A Step By Step Guide To The IVF Process: Step Seven -- Embryo Transfer

Embryo Transfer

Dear Readers: This is the seventh and final part in the series I have begun to help answer what In Vitro Fertilization (IVF) is and how it works with my world-wide Blog audience. What you read here is what I also provide my patients with on a daily basis. I plan on going into some detail but in a way that is understandable to the normal (lay) audience, and not the medical or scientific one. I also hope that this will not only clarify what you will go through, but explain why things are done in a certain way and what the goals of each step are. I also want to convey that IVF is actually a replacement for some of the “natural” steps required to get pregnant and not some miraculous high tech fertility treatment that gets patients pregnant artificially, as many think it is. It is somewhat of a miracle that we can do as much as we can, but there are still lots of things/steps that we cannot do or influence. I hope this discussion will benefit you. This series has been posted over the past weeks in installments. (For earlier installments in correct order scroll down to the beginning of July 2012)

STEP SEVEN: EMBRYO TRANSFER

In my previous entries, I have been discussing each of the steps involved in In Vitro Fertilization (IVF). By this point, the ovaries have been stimulated with fertility drugs to recruit and grow follicles, where the eggs are located, these follicles have been aspirated to retrieve the eggs, the eggs have been put with the sperm and allowed to fertilize and the fertilized eggs, now embryos, have been cultured and allowed to grow. We are now at the step where the embryos have to be returned into the womb (uterus) for the final stages to occur so that a pregnancy can result. Embryo transfer is essentially the last step for IVF and the farthest this technology can take us to influence whether or not a pregnancy can occur. This is the step that replicates the natural step where the embryo enters the uterus. From that point, the embryo has to hatch out of its shell and attach to the uterine lining, and then the lining has to grow around the embryo, which is implantation. At that point, beta HCG hormone will be produced and testing for this hormone will be detectable by blood testing. This is a positive pregnancy test. So, as you can now understand, IVF is NOT a perfect technology and, in reality, cannot get make you pregnant. It can help you to become pregnant or expedite the natural process. It still requires your body or nature or God to influence the final steps so that a pregnancy can ensue. Because of the limits of current technology, we cannot yet attain 100% pregnancy rates.

Failure after the embryo transfer of good embryos is often referred to as "implantation failure" but this is not necessarily the cause of the failure. There are many little steps in this final process, which I will explain, that influence whether or not actual implantation will occur. If you fail an IVF cycle, it may not necessarily indicate that there is something wrong with you. It could be the embryo’s fault, the doctor’s fault, the uterine lining’s fault or your body’s fault. Unfortunately, there is no testing that can be done at this step to help with the specific identification of what did not occur and so it is lumped into one big category, “implantation failure.”

The exact protocols and procedures done at the embryo transfer step can vary widely among clinics. They can vary even among doctors in the same clinic. I’m sure that I will not be able to explain all or cover all variations, because many are clinic, country and physician specific, but I will mostly cover the protocol that I use, and of course, think is the best way. But don’t fault your doctor if they don’t do it the same as I do. I’ll try to generalize as much as possible.

PRE-TRANSFER COUNSELLING

In most clinics, the doctor doing the transfer will meet with the patient to go over the findings of the embryo culturing and reveal how many embryos are available to transfer, what they look like and give some type of recommendation as to how many to transfer. The number to transfer will likely depend on the patient’s age, the quality of the embryos (based on their appearance) and specific regulations or laws governing the clinic. An example of the latter is that many European countries with a large Catholic base disallow transferring more than one embryo. In the U.S., we don’t have a specific law or regulation that restricts the number of embryos to transfer, but most clinics are members of the Society for Assisted Reproductive Technology (SART), a division of the American Society for Reproductive Medicine (ASRM), which over sees IVF, and the society has specific recommendations for the number of embryos to transfer for each age group and based on embryo quality. This was put into place because of the desire and need to reduce the incident of multiples (twins or higher) that occur with IVF. When evaluating clinics and their pregnancy rates, that is something you may want to look at. Studies have shown a near equivalent pregnancy rate with single embryo/blastocyst transfer but all those studies don’t look at per cycle rates but cumulative rates. That is, it may take two to three cycles to get the same pregnancy rate as a clinic that transfers two to three embryos in a single cycle. But it seems that those single embryo transfer rates are getting better and closer to multi-embryo transfer rates per cycle. Eventually we will probably have the technology to identify the perfect embryo in its entirety so that we can just choose one to transfer and not have to hedge our bet by transferring more than one. At this point in time, we don’t have that ability. So this is one aspect of IVF that you might want to check on when choosing an IVF clinic, that is, do they have a policy that restricts you to single embryo transfer (SET) and what is their per cycle pregnancy rate.

Prior to the embryo transfer, my procedure is to meet with the couple and do a review of the cycle up to that point, explaining each step and the results. I then show them a chart that indicates where each embryo is in terms of the number of cells they have attained to that point, and the quality based on how they look (grading). I also show them a chart that has tracked their development each day so that we can see how each embryo has evolved and to verify that they are dividing at a good rate. This latter chart or evaluation is important because it is one way to help determine which embryos are behaving as healthy embryos versus ones that are not dividing well, or unhealthy. This also helps to eliminate embryos from being transferred and that are eligible for freezing. I will then provide them with a counseling sheet, that they sign, that shows what the SART recommendations are and what category they fit into based on their age. I also give them my personal recommendations and share my multiple gestation rate based on how many embryos were transferred (this is based on cumulative data over the 18 years I have had my clinic and when we were transferring a lot more embryos than we do now). I am not yet personally confident about single embryo transfer and so do not encourage it unless a patient does not want to take the risk of a twin pregnancy at all. I average transferring two embryos now and try to follow the SART guidelines. I rarely do single embryo transfers but again, keep in mind that this is a personal preference and I don’t like to risk a failed cycle with my patients. There are many clinics that now only do single embryo transfers and, as long as their pregnancy rates support that decision on a per cycle basis, then that is fine. If their per cycle pregnancy rates suffer because of this policy then I feel they are not taking the patient’s emotional and financial risks into consideration.

Because I usually transfer two to three embryos, I make sure to explain the risks associated with a multiple gestation, especially the risk of loss of the pregnancy due preterm delivery, as well as, the complications that can cause the pregnancy to be a hardship for the patient. Ultimately I believe the patient has the right to make the decision, since they are paying for the procedure, but, at the same time, I will not allow them to go overboard on how many to transfer and make a poor decision, so the ultimate decision is a combination of their choice, as well as, my endorsement of that decision. Once we have had this discussion, we then decide which specific embryos to transfer. Due to the lack of any other technology to help us decide which embryos are the best embryos, we will choose the two embryos that look the best (highest grade) and have been developing appropriately. In my consultation sheet, I indicate which two embryos this will be so that the embryologist knows what we chose. I then also recommend what to do with the remaining embryos as to whether to freeze, culture further or discard them. I then indicate those specific choices as well on our transfer form. Finally, the patient signs this transfer form to verify their choices since, after all, the embryos belong to them and we need their permission to do anything with their embryos.

PRE-TRANSFER PATIENT PREPARATION

In this step, clinics will vary highly so this is only a guideline based on what I do. It may not be the only way or the way your doctor proceeds. I put on sterile gloves and then measure the embryo transfer catheter and mark how far the catheter should be inserted. This measurement is based on the MET (mock embryo transfer) that I did prior to the start of the IVF cycle. Before the ultrasound was used to verify the position of the catheter (ultrasound guided embryo transfer), this measurement was the only way that we knew where to put the embryos. Fortunately, someone was smart and astute enough to think to use the ultrasound to help identify the position of the catheter within the uterus, which I think immensely helped increase pregnancy rates. Since doing ultrasound guided transfers, I have had many situations where I changed the position of the catheter beyond the original measurement based on the ultrasound visualized position. In any case, I still mark the position on the catheter just in case I am unable to visualize the catheter by ultrasound, which can happen in heavier patients, patients with retroflexed uteri and patients without sufficient urine in their bladder. It’s my back-up.

The embryologist will then come to the transfer room and I will give her (it’s a her in my clinic and this is not intended to be sexist), and recite the name of the patient and the number of embryos to be transferred. The embryologist then repeats that information back to me. This is my protocol for verifying the identity of the patient and to make sure the embryologist knows who the patient is as well. From this point, the embryologist returns to the laboratory to load the appropriate embryos into the catheter. Some clinics with multiple embryologists might have an additional identity verification step in the lab when the embryos are being drawn into the catheter where a second embryologist recites the name of the patient and confirms that the identifying information for the embryos is the same as the name they’ve recited. Our embryos are strictly identified as to which incubator they are in and where in the incubator they are placed, as well as, identifying information on the Petri dish. The petri dishes are placed apart and in unique positions i.e. different incubators, different racks and different positions on the rack, so that they don’t get mixed up. All that information is noted in the embryologist’s log. Verification of all this information is part of the embryo identification protocol.

In the meantime, I then prepare the patient for the procedure. The patient is placed into the lithotomy position, the same position as doing a pap smear. In the center where I trained, the patient was placed either on her tummy with the bottom up or on her back in the lithotomy position based on whether the uterus was angled up or toward the back. That type of positioning has not been shown to make any difference in pregnancy rates so I just use the one lithotomy position. In patients with a uterus that is angled up (anteverted or anteflexed), I will tilt the bed a little more so that the patient’s head is lower than her bottom but not so steeply that she is uncomfortable. Again, using sterile gloves and sterile technique, a sterile speculum is placed into the vagina. I will then irrigate the cervix and surrounding area with culture media using a forceful but gentle squirting technique. No antiseptics are used because this can kill the embryos. Next, I remove my first set of gloves and help position the abdominal ultrasound transducer to find the uterus, and make any adjustments I need to make to the ultrasound machine. My assistant has been trained to do this as well and holds the transducer in the proper position. That frees me up to do the transfer procedure. Because the ultrasound sound waves have to pass through the abdominal tissues of fat and muscle to reach the uterus, there has to be adequate filling of the bladder for the sound waves to pass through and get deep enough to see the uterus. Too much filling is just as bad as not enough because it pushes the uterus further back and farther away from the ultrasound transducer. A bladder that is uncomfortably full can also cause bladder spasm, causing pain, and uterine contractions which will adversely affect the chances of pregnancy. Inevitably there are cases where we can’t proceed with the transfer because the bladder is not full enough and therefore have to allow the patient to drink and fill her bladder, or have to have the patient go to the bathroom to let out some urine or sometimes use a bladder catheter to drain some. But if the bladder is filled properly, we can see the uterus and, more importantly, the endometrial lining so that we can see the catheter pass within. We are then ready to proceed with the transfer procedure.

THE TRANSFER

By now, the embryologist returns to the transfer room with the loaded catheter. As she enters the room, she again recites the name of the patient for verification. Both I and the patient acknowledge that she is correct. I then put on new sterile gloves, since I will be handling the catheter with the embryos. Since most uteri are angled, and since I already know the specific direction of the patient’s canal based on the previously performed MET that I have documented on an MET form, as well as, what I know from her previous ultrasounds, I will usually need to put a curve in the introducer. I use an embryo transfer catheter that has an outer sheath (introducer) through which the catheter passes. The embryo transfer catheter is very very soft and without an introducer, would get stuck in the crevices of the cervical canal. The introducer helps it to pass through the canal and get into the endometrial cavity. I put the curve in the introducer after the catheter has been pulled back a bit so as not to squeeze the catheter inadvertently (that would be very bad because the embryos could be pushed out from that pressure). Sometimes in doing the transfer it can take several attempts to place the introducer because it can take several attempts to get the right angle, or the introducer doesn’t hold the angle long enough. I then advance the introducer into the cervix to the point of the internal cervical os but not farther. I do not advance the catheter with the embryos through the introducer until I know that the introducer is in the proper place, just beyond the internal os. I don’t want any resistance or difficulty advancing the catheter, which could influence pregnancy rates.

The technique of the embryo transfer is one of the most important steps in IVF. I cannot emphasize that enough. It is this technique that usually causes varying pregnancy rates among doctors. This step is important because even if you have the most beautiful and healthy appearing embryos, if the transfer is not done properly and with utmost gentleness, pregnancy will not occur. Many studies have been done comparing transfer techniques among Physicians and even among Physicians in the same group and found wide variations in pregnancy rates. This is attributed to the technique of and gentleness of the embryo transfer. It is absolutely critical that no bleeding is induced, because blood is toxic to the embryo, and that the back of the uterus is not touched, which can cause uterine contractions leading to failure. For this reason, I consider it very important that the Physician doing the transfer knows your uterus because he/she has done the MET before and practiced the transfer, and is not learning your cervical canal and uterine cavity for the first time. This point is especially important if you have a very deviated, curving or abnormal cervical canal. This is a problem with many, if not most, large IVF clinics because you may have the transfer done by a doctor that has never met you due to their cross-coverage schedule.

I also think that this is where experience is very important. You want to choose a doctor that has done a lot of embryo transfers. A recent study in the U.S. found that a Fellow (an Ob/Gyn doctor undergoing specialty training) graduating from an infertility fellowship (advanced training) in the U.S., has only done an average of three embryo transfers. That would be like a new doctor that has only done three cases in a specific surgery. Essentially, they are not yet expert in that technique or surgery and therefore still need to “practice”. I agree that all doctors need to gain experience when they are just starting out, and most fellowship programs are unable to allow an untrained doctor to learn on their cash paying patients, but if you have a choice and since you are spending $10,000 or more for this treatment, just like with surgery, wouldn’t you want the doctor with the most experience so that you have the best chance of success?

To continue: so now, the introducer is in place and the catheter is very gently fed through the introducer into the endometrial cavity to a point that had been pre-measured. The ultrasound also helps to see the catheter tip to verify its location and make sure that it is in the proper place. If the catheter is seen as not in the proper place, then the position is adjusted to put it in the correct position. Technically the catheter is not placed all the way to the end of the endometrial cavity. Studies have shown that the optimal placement is 0.5 to 1 cm from the top of the endometrium. The embryos are then very slowly injected into the cavity. The embryos are within a bubble of culture media so that fluid injected can be seen but the embryos cannot because they are too small. I then allow the embryos to settle for 30 seconds but that is how I was trained. Other doctors may just quickly remove the catheter which is okay as well. Studies show no difference. From this point, I tell my patients not to move, cough, sneeze, laugh or talk above a whisper in order to minimize abdominal pressure on the uterus. Again, this is a precaution I take but probably is not an absolute necessity. I then return the catheter to the embryologist and she returns to the lab to verify that the embryos have been expelled. Sometimes embryos will reflux back into the catheter. Studies have shown that if the refluxed embryo is returned to the uterus immediately, pregnancy rates will drop because of the likelihood of disturbing the embryo that remained. In some cases, the previous placed embryo can be aspirated with the second procedure and be injured. For this reason, my recommendation is not to do a second procedure to replace the refluxed embryo. It is left out and allowed to be frozen. I have already counseled my patients about this possibility in the pre-transfer counseling so the plan is already set. The only situation where I would repeat the procedure is (1) if all the embryos refluxed and there are none left inside, which can occur when mucus plugs up the catheter opening, or (2) if the best embryo refluxes in a group where several embryos are being placed and the other embryos are poor quality (as in a patient that has a low number of embryos to transfer).

Once the embryologist informs me that there were no refluxed or retained embryos, we then place the patient in position to rest for 30 minutes. It is my protocol to have the patient rest after the transfer, more for psychological reasons than medical reasons. In fact, studies have shown no differences in pregnancy rates if the patient rests or gets up right away. Since the patient is in lithotomy (pap smear) position, and we don’t want the patient to use any muscles to move into place, I put the table into a head down or trendelenberg position (this is where the patient is tilted to be head down). In this position, I and my assistant have the assistance of gravity to easily slide the patient up to the top of the bed without the patient pushing. I then return the bed to a flat position so that she can rest.

From this point in the overall IVF treatment, the patient continues the medications that were started at the time of the egg retrieval to support the luteal phase and prepare the endometrium for implantation. Again, these medications and hormones are to help with the implantation step but cannot make implantation take place.

So now the IVF procedure is essentially done. There are no other techniques or procedure to be done because this is the extent of the technology. The process is again a natural process from this point. The embryo needs to continue developing to a blastocyst, if it was a day #3 transfer, needs to hatch out of its shell, attach to the endometrium and then the endometrium needs to engulf or grow around the embryo (implantation). Failure at any one of these remaining steps can cause failure in the cycle. As mentioned previously, if the transfer is not done well, then despite having the very best embryos, failure will occur. Also, if the embryo does not continue its development to the blastocyst stage then that is the end of the process; or if the embryo does not exit (hatch) from its shell, then it will not be able to attach to the endometrium and that is the end of the process; or if the endometrium does not engulf the embryo because it is not in the correct anatomical form, timing is not correct, or other possible factors that we don’t completely understand, then the process is at an end. Any of these factors can lead to what we refer to as “implantation failure” and is the reason why we often don’t have solutions for failure at this step. Some people might ask about “assisted hatching” which I have not explained yet. Assisted hatching is where a small hole is placed into the shell of the embryo. All it does is give the shell a defect where the inner embryo can emerge from, but the process of emerging or hatching is still dependent on factors within the embryo. So having assisted hatching does not guarantee that the embryo will in fact hatch out of the shell. However, in older eggs, where we know the shell is often too thick or if the embryologist measures the zona (shell) and finds that it is too thick, it may be a good idea to have assisted hatching done.

I would also like to mention some technologies that have been advertised that are not yet verified and accepted universally. One of those is laser drilling of the endometrium, where a small laser is introduced into the endometrial cavity to make a hole where the embryo can be placed. You need to understand that implantation is NOT the embryo making a hole and burying itself into the endometrium, rather, it is the process by which the endometrium grows around the embryo. As logic dictates, making a hole probably does nothing to help the process. A second technique that I have heard of is using “embryo glue”. I don’t have detailed information about this “glue” since it is proprietary, but again, this may help the embryo to stabilize itself in a certain point in the endometrium, but it does nothing to help the embryo hatch out of the shell or help the endometrium to grow around the embryo. So, again logic dictates that it doesn’t make sense for this to help with implantation. As a result, and expectedly, neither of these techniques have been shown to be of benefit in any legitimate studies.

THE TEN DAY WAIT

So we have now come to the end of the IVF procedure and the maximum that our technology can help a person to achieve a pregnancy. We are at the point where we have to wait to see if the next steps happen on their own. If a day #3 transfer was done, it will take approximately 7 days for the remainder of the process to be completed and for the pregnancy test to be positive. For that reason, I do my pregnancy tests at 8 or 9 days post transfer. For a blastocyst transfer, you only need three more days to get a positive pregnancy test. I know that some clinics want to be absolutely sure so they wait for 14 days but the problem with that protocol is that an early chemical pregnancy will be missed, and in my opinion, it is important to know if a chemical pregnancy occurred or not. This event is important to know because it verifies that the patient can become pregnant with IVF and that the last steps actually occurred. With that knowledge the patient can be reassured that this treatment can work, that her body can do what it needs to do, and it is just a matter of getting a perfect embryo into her womb for her to be successful. The majority of chemical pregnancies occur because the embryo is genetically abnormal. It would be good to know that those last steps, those steps that are beyond our technology, can occur on their own.

PERSONAL THOUGHTS

Before I leave the patient to rest after the embryo transfer, I say a little prayer because I know that this is the point where God takes over, and so I will leave this prayer for you to use if you wish to pray to whichever God you believe in: “Dearest Lord God, Bless this couple with fruit of the womb and Grant their wish for a Child. We ask this through your Son, Jesus Christ. Amen”. I hope that this series has been valuable to your understanding of the process that you will be or are going through, and I wish you the best of luck and blessings to eventually realize the wonderful dream of having a child. It may seem very expensive, arduous, stressful and emotionally draining but when you are successful and hold that baby in your hands, you will realize that it was more than worth what you went through.

My mother used to always tell me that “if you want something bad enough and it is something very valuable, there will be no easy way to get there and you will have to work harder for it.” She was referring to careers and my desire to become a doctor, but as a former IVF patient, I know that this same advice applies to doing IVF as well. It is neither an easy path nor a guaranteed path. With the technology that is now available in fertility treatments, the only thing that can cause you to ultimately fail is yourself, when you give up trying. Otherwise, if you are open to all the options available and want a baby bad enough, you only have to choose to keep trying, consider all your options, revise your strategy and not forget to look forward to your goal, the success in the end; holding that new baby, and not the failures of the past or the path you had to go through.

God Bless you on your journey.

Edward J. Ramirez, M.D. F.A.C.O.G.
Medical Director, Monterey Bay IVF
Monterey, CA
http://www.montereybayivf.com/

A Step By Step Guide To The IVF Process: Step Six -- Embryo Development

Blastocyst
 

Dear Readers: This is the sixth part in the series I have begun to help answer what In Vitro Fertilization (IVF) is and how it works with my world-wide Blog audience. What you read here is what I also provide my patients with on a daily basis. I plan on going into some detail but in a way that is understandable to the normal (lay) audience, and not the medical or scientific one. I also hope that this will not only clarify what you will go through, but explain why things are done a certain way and what the goals of each step are. I also want to convey that IVF is actually a replacement for some of the “natural” steps required to get pregnant and not some miraculous high tech fertility treatment that gets patients pregnant artificially, as many think it is. It is somewhat of a miracle that we can do as much as we can, but there are still lots of things/steps that we cannot do or influence. I hope this discussion will benefit you. This series will continue to be posted over the next few weeks in installments. (For earlier installments in correct order scroll down to the beginning of July 2012.)

STEP SIX: EMBRYO DEVELOPMENT

At this point, we have gotten the eggs out of the ovaries, put them with the sperm or injected the sperm into them and fertilization has occurred. Each of these steps has lead to a decrease in numbers from the original number of follicles. Not all the follicles had eggs retrieved from them, not all of the retrieved eggs were mature and therefore could not be fertilized, and not all of the mature eggs fertilized or fertilized normally. So now we are left with a cohort of embryos that have fertilized normally and are ready to grow and develop into embryos that can be transferred.

At the end of fertilization, normal embryos are in a 2PN stage, or two pronuclei and is one cell. These are placed into special media that provides the proper nutrition for these early embryos to grow and develop. This is key for the growth of embryos. Embryo culture media has been researched and developed over the evolution of IVF technology, researching and finding the proper combination of chemicals to mimic the intratubal environment. In the natural process, the embryo is within the tube and develops and divides as it makes its way down toward the uterine cavity. So the culture media has to match the media that would be found within the tube. In addition, the environment, such as gas ratios and temperatures, have to match as well. So the requirement for embryo development is to have the proper nutrition within the Petri dish, the proper temperature within the incubator and the proper gas mixture within the incubator as well. Also, the embryo needs to be protected from airborne contaminants outside of the incubator. These factors are so critical that they will influence the success rates of an IVF clinic.

Many embryology labs, such as mine, are designed and constructed to the standards of a “clean” room, such as that used in Silicon Valley for making silicon chips. The airflow within the room is isolated. In other words, the airflow is completely separated from the air outside of the room so that there is little contamination from in the outside. In my lab, the airflow is set to be a positive flow, meaning the air pressure within the room exceeds the pressure outside the room so that when the door is opened the air pushes out rather than allow the outside air to push into the lab. In addition, the airflow within the lab is cleaned by a HEPA filter and Charcoal filter to filter out small particles and chemicals, called VOC’s or volatile organic compounds. VOC’s are the fumes or gasses you can smell after a room is painted or a road is repaved, but there are VOCS’s that can’t be smelled as well. These chemicals can kill or injure embryos so that they don’t continue their development. Finally, the embryology lab temperature must be maintained so that when the embryos are taken out of their warm environment to be checked, their temperature does not drop abruptly. When choosing an IVF clinic, it would be wise to ask about their lab set up and, if possible, tour the lab to see how well the environment is. Many centers have certification by the College of American Pathologists (CAP) which means they have undergone a survey, which includes evaluation for many of the aforementioned criteria for labs, and have passed and received certification of their lab.

If all of the above quality controls are in place the embryo can proceed with development to a stage where they can be transferred into the uterus. The embryo actually can be transferred at any point in its development, but time and research has identified the two optimal embryonic ages as day #3 or day #5. These are the two ages that most IVF centers in the world use in their transfer protocols.

So, by the day after fertilization (48hrs after retrieval) has taken place, the embryo has developed into a 2-4 cell embryo, in normal development. Sometimes embryos will have progressed further than 4 cells but that can either be because the evaluation of the embryo was later in the day (48hrs) or the embryo is developing faster than expected, which could be an indication of an abnormal embryo. Embryos are also examined for external features and a grade is given. There is no universally accepted standardized method for grading but they are all essentially similar. They are all based on the external or “morphological” characteristics of the embryo as viewed through a microscope. Almost all labs will count the number of cells that the embryo has on that particular date, up to the Morula stage where individual cells are no longer visible. They will also give it a grade (A,B,C or 1,2,3) based on the clarity of the embryo. That is, the amount of fragmentation or debris located within the cell. These fragments are pieces of tissue that have been extruded in cell division. Although cells with high amounts of fragmentation have been related to decreases in pregnancy rates, that is not an absolute. I have had the worst looking embryos lead to pregnancy, as have many other clinics. But, we know that most successes come from cells that either don’t have any fragmentation or a minimal amount. Finally, most clinics will look at the symmetry of the cells; do they look fairly equal or are there larger and smaller cells. In my practice, we use a simple 1,2,3 grading system where the embryos are evaluated for fragmentation and symmetry, and the combination of those two factors lead to a grade. Some clinics break these down and give two grades for each embryo; one to represent fragmentation and one to represent symmetry, and some use letters instead of numbers. In 2010, the Society for Assisted Reproductive Technologies released guidelines for grading embryos in the hope of standardizing this among IVF centers within the United States. In their system, cleaved embryos (those before morula stage) are evaluated for the number of cells present, fragmentation (0%, 1-10%, 11-25%, >25%) and cell symmetry (perfect, moderate asymmetry and severe asymmetry). Embryos are then given a score of Good, Fair or Poor.

The biggest disadvantage of current embryo evaluation methods is that it is essentially a beauty contest, so as I explain to my patients, Grade A or 1 or Good is “beautiful”, Grade B or 2 or Fair is “average” and Grade C or 3 or Poor is “ugly.” We know that most pregnancies come from Grade 1 or 2 embryos and only Grade 3 embryos have a decrease in pregnancy rates. This method does little to evaluate the internal quality of the embryos, which we know is really the main determining factor for embryo health or viability. That technology is yet to be developed. Embryo chromosomes can be determined by removing one of the cells and checking for its chromosomes, a procedure known as Preimplantation Genetic Screening (PGS/PGD), but this still does not evaluate the structures within the cytoplasm, or outside of the nucleus where the chromosomes lie, which are the structures that provide the energy for the embryonic cell. When looking at embryos to decide which to transfer, not only must the embryo appearance be taken into consideration, but its development rate must be considered as well, as an indirect measurement of embryo health. I’ll discuss this decision more in the next step.

To summarize the stages of development, at 24 hrs after egg and sperm have been put together (day of retrieval), the embryo is a 1 cell 2PN; at 48 hrs (Day#2) it is 2-4 cells; at 72 hrs (Day#3) it is 6-8 cells; at 96 hrs (Day#4) it is usually a compacting Morula; at 120hrs (Day#5) it is a Blastocyst. There is some variability to this development scheme as embryos do have differences in rate of division. In a natural (non-IVF) cycle, the embryo is usually at the Blastocyst stage when it reaches the endometrial cavity. In IVF the transfer is done either on Day#3 or Day#5. Because of the political pressure to do more single embryo transfer cycles, or 1 embryo transfers, many clinics are now culturing to Blastocyst stage before doing the transfer. This is because culturing to Blastocyst stage leaves less embryos to choose from and MAY indicate a healthier embryo, but the latter conclusion is not an absolute.

In my center, I have specific criteria to determine whether or not to proceed to Blastocyst. One of these criteria is that there has to be a minimum of 8 good quality embryos (7-8 cell, grade 1) because I know that many embryos will not make it to Blastocyst, and that is not necessarily because the embryos are bad. In doing PGS, I have seen Blastocysts turn out to be chromosomally abnormal embryos whereas an embryo that did not survive to Blastocyst had normal chromosomes (PGS usually is done with Day#3 embryos and takes two days to get the result so by the time the result comes back, the embryos are Day#5). I have also seen ugly poor looking embryos (4 cell, Grade 3) lead to pregnancies when transferred at Day#3 that would not have survived to Blastocyst. My reasoning is that Blastocyst culturing is not a perfected technology yet. A clinic that puts only a few embryos at risk to develop to Blastocyst is basically risking the cycle by not having anything to transfer. For that reason, I want to make sure that there are enough embryos to start with so that there will be embryos to transfer. In addition, it is still my personal belief that the uterine cavity is a better culture environment and media than what we have available in the lab. For this reason, most of my transfers are on Day#3, but I have colleagues who now transfer mainly Blastocysts. So, when looking at these transfer options with your doctor, ultimately the decision has to be made based on pregnancy rates at Day#3 vs Day#5 transfers and not just because you only want to transfer 1 embryo.

In the next entry we’ll discuss embryo transfer and the decisions that go into this step, as well as, the critical parts of the transfer technique.We will continue this discussion soon with the next installment, "Step Seven: Embryo Transfer". Thank you for joining me today!

Edward J. Ramirez, M.D. F.A.C.O.G.
Medical Director, Monterey Bay IVF
Monterey, CA
http://www.montereybayivf.com/

A Step By Step Guide To The IVF Process: Step Five -- Fertilization

Dear Readers:

This is the fifth part in the series I have begun to help answer what In Vitro Fertilization (IVF) is and how it works with my world-wide Blog audience. What you read here is what I also provide my patients with on a daily basis. I plan on going into some detail but in a way that is understandable to the normal (lay) audience, and not the medical or scientific one. I also hope that this will not only clarify what you will go through, but explain why things are done a certain way and what the goals of each step are. I also want to convey that IVF is actually a replacement for some of the “natural” steps required to get pregnant and not some miraculous high tech fertility treatment that gets patients pregnant artificially, as many think it is. It is somewhat of a miracle that we can do as much as we can, but there are still lots of things/steps that we cannot do or influence. I hope this discussion will benefit you. This series will continue to be posted over the next few weeks in installments. (For earlier installments in correct order scroll down to the beginning of July 2012.)

STEP FIVE: FERTILIZATION

In the previous step, the eggs were aspirated and retrieved from the ovaries, the equivalent of ovulation in the natural process. These eggs have been collected and the embryologist now isolates each egg within a petri dish. The eggs are prepared for the fertilization step. In the natural cycle, after ovulation, the egg needs to pass through the culdesac of the pelvis to find the fimbria of one the tubes. In the normal anatomical position, the fimbria of the tubes are lying within the culdesac. If there is scar tissue within the culdesac or the anatomical positions of the tubes are altered, then this “pickup” step may not occur. This would be an indication to do IVF. If this does not occur, then that is the end of the process in that cycle. If it does find the tube, it is then brought into the tube and through peristalsis (muscular motion) within the tube it is pushed to a portion of the tube where the sperm need to be waiting to accomplish fertilization. Again, if the sperm are not there, then fertilization will not take place and the cycle ends at that point. If the sperm is in the correct position at the correct time, then sperm attach to the egg and one sperm penetrates the egg to accomplish fertilization. In IVF, these two steps are accomplished by laboratory means, so there is little chance that those steps will not be accomplished. This is another step that IVF accomplishes for your body, thereby enhancing your chances of success. It is not left to chance as in the natural process.

At this point, there are two ways to accomplish fertilization. It can be allowed to occur by natural means, meaning the sperm can be added and the egg-sperm interaction allowed to happen on its own, or it can be assisted, also known as ICSI or "intracytoplasmic sperm injection". In order for the fertilization process to occur, a sperm needs to penetrate the outer lining (shell) and enter the egg and then there is an elaborate process within the egg whereby the nucleus of the egg and the nucleus of the sperm unite. This latter process is the actual process of fertilization. Just putting a sperm into the egg is NOT fertilization. The second part of the process, a natural step, has to occur on its own. In other words, just doing ICSI is not fertilizing the egg and does not guarantee fertilization. ICSI is just putting the sperm within the egg so that fertilization has the possibility of happening.

If natural fertilization is going to be done, the egg and sperm are put together and the sperm is allowed to penetrate the egg on its own. But if injection of the sperm is going to be done, then the embryologist removes the filmy lining of the egg, called the cumulus. This will also allow evaluation of the maturity of the egg. Only mature eggs, in Meiosis stage II, can be fertilized. Eggs can be in either Meiosis stage II (M2), Meiosis stage I (M1) or Germinal Vesicle (GV) stages at the time of retrieval. As explained previously, the follicles, and the eggs within, don’t all mature at the same rate. That leads to some larger follicles and some smaller follicles. The larger follicles have the matured eggs, eggs that have had the time to mature, and the smaller follicles have immature eggs. As a result, eggs in the various stages can be retrieved, but only the mature ones will fertilize. In the case of Meiosis stage I eggs, these can be left in culture and allowed to mature, if the clinic has an egg maturation program and the proper media in place, or in some cases, just waiting will allow the egg time to mature to the mature Meiosis stage II. They can then be fertilized at that time. So with ICSI, an anatomically normal appearing and swimming sperm is identified and aspirated into a glass needle. This needle is then inserted into the egg and the sperm is then injected within. All of this procedure is done microscopically. ICSI essentially assists the step whereby the sperm enters the egg. This procedure is done mostly in cases where there is an abnormality of the semen analysis, since it is known that with abnormal semen analysis, there is a high possibility of a functional problem i.e. that the sperm cannot fertilize the egg. Also, it is recommended in older patients (>37 years old) because the shell of the egg is thicker and sperm have a more difficult time penetrating the shell normally. In some cases, patients will choose to have ICSI because they don’t want to take the risk of fertilization not taking place (fertilization failure), which will essentially end the cycle at that point. Without fertilization, embryos are not formed, and no embryos means there will be nothing to transfer.

Once the eggs are put with the sperm, the petri dishes are placed into an incubator. Fertilization will take a minimum of 12 hours to occur so most clinics will re-evaluate the eggs the next morning for fertilization. It is expected that some eggs will fertilize normally, called a 2PN stage, some will not fertilize and some will fertilize abnormally (1PN or 3PN). Because of this, there will be another reduction in the number of eggs available to use. With fertilization, the egg is now referred to as an embryo. A typical threshold to evaluate fertilization is to expect a minimum of 50% of the available (mature) eggs to fertilize. If that threshold is not reached, it could be because of egg quality, sperm quality or lab quality. Only the fertilized embryos can be cultured to develop into embryos that can be transferred back into the womb, so this number essentially establishes how many might be available for transfer. Fertilized embryos are now transferred into a new culture media and placed in incubators that have a specific gas content and temperature to allow them to grow.

We will continue this discussion soon with the next installment, "Step Six: Embryo Development". Thank you for joining me today!

Edward J. Ramirez, M.D. F.A.C.O.G.
Medical Director, Monterey Bay IVF
Monterey, CA
http://www.montereybayivf.com/

A Step By Step Guide To The IVF Process: Steps Three And Four--Egg Retrieval

Dear Readers:

This is the fourth part in the series I have begun to help answer what In Vitro Fertilization (IVF) is and how it works with my world-wide Blog audience. What you read here is what I also provide my patients with on a daily basis. I plan on going into some detail but in a way that is understandable to the normal (lay) audience, and not the medical or scientific one. I also hope that this will not only clarify what you will go through, but explain why things are done a certain way and what the goals of each step are. I also want to convey that IVF is actually a replacement for some of the “natural” steps required to get pregnant and not some miraculous high tech fertility treatment that gets patients pregnant artificially, as many think it is. It is somewhat of a miracle that we can do as much as we can, but there are still lots of things/steps that we cannot do or influence. I hope this discussion will benefit you. This series will continue to be posted over the next few weeks in installments.

STEPS THREE AND FOUR: EGG RETRIEVAL

Thus far, we have covered the first two steps in the reproductive process. In the natural process, the brain has sent signals to the ovaries to recruit and grow the follicle and mature an egg within. The same process has been done in IVF through stimulation by the fertility medications. The follicles have grown and the eggs within have gone through their maturation process. In a natural cycle, one follicle will rupture and the fluid will rush out, taking the egg with it, and empty into the cul-de-sac. The egg will then have to find its way to the fimbriated end of one of the fallopian tubes. Follicular aspiration is the way that IVF accomplishes the ovulation step so that the egg can be retrieved. It is also the method that the egg and sperm are brought together, and therefore, a substitute for finding and being picked up by the tube.

Egg retrieval is technically known as "transvaginal ultrasound guided oocyte (egg) or follicular aspiration". It is a relatively safe procedure and simply put, just a needle poke, like drawing blood. There are some potential risks to this procedure, as with all medical procedures, such as causing bleeding, infection, organ injury or pain but these risks are very minimal and rarely occur. As with all surgeries or procedures, the experience of the physician directly influences the risks. The more experience a physician has doing the procedure, the lower the risks. In many centers, some form of conscious sedation is used so that the patient does not move or feel pain. Despite the quick duration of the procedure, the ovaries are very sensitive and can elicit a large amount of pain. There are some clinics that do not use any sedation, however, and a few that still use general anesthesia where the patient is intubated.

Some clinics will use an Anesthesiologist or Nurse anesthetist to give the conscious sedation and monitor the patient during the procedure. The safety of this set-up is that the physician doing the procedure does not have to be distracted by constantly thinking about the patient’s vital signs, and thus will be able to concentrate fully on just the aspiration part of the procedure. Also if the patient has any difficulties, such as difficulty breathing, bronchospasm, inadequate sedation or increased movement, the Anesthesiologist can attend to it without the fertility physician having to stop the aspiration procedure. The procedure takes 5-20 minutes to perform depending on the skill of the physician, the number of follicles to be aspirated and whether or not the physician uses a technique of follicular flushing (rinsing out the follicle with culture media after the initial aspiration).

The procedure proceeds as follows:

The patient is placed into an operating suite or procedure room, vital sign monitors are placed, the patient is put into the lithotomy (or pap smear type) position and the sedation medication given. In some cases, sterile drapes are put in place, but this is not absolutely necessary. In most clinics, a vaginal speculum is placed and the vagina irrigated with sterile water. Betadine or similar antiseptics are NOT used because they could be lethal to the egg if the solution contaminates the aspiration needle. Local anesthesia is not used in this procedure. Once the vagina has been thoroughly irrigated, the speculum is removed. Just as was done with a vaginal probe to view and monitor the follicular growth, a vaginal probe is used to visualize each ovary, but in this case, a needle guide has been mounted to the probe. This needle guide is so that a needle can be directed to where the probe is pointing. The vaginal ultrasound probe, with the needle guide mounted, is then placed into the vagina once the patient is sedated, and a quick inspection of the ovaries are carried out to verify position and confirm that the follicles are intact. If ovulation had occurred prematurely, the follicles would be absent. The probe is placed toward one side so that it can clearly see one ovary.

With IVF, the ovaries usually fall into the cul-de-sac, a space behind the uterus, which is located just on the other side of the vaginal wall, so the probe is actually millimeters away from the ovary and the ovary can be seen clearly. In addition, the probe is almost in direct contact with the ovary. There is only a small amount of vaginal wall between the probe and the ovary. The needle can then be easily passed through the vaginal wall, into the ovary and into the first follicle to be aspirated. Once within the ovary, it can then be moved from follicle to follicle to aspirate (or vacuum extract) the fluid within the follicle. It does not need to be removed and reinserted for each follicle. Basically the physician will move from follicle to follicle aspirating each follicle until all the fluid is removed. If the physician uses a flushing technique, the fluid will first be aspirated then culture media is injected back into the follicle and aspirated. This is done several times. Some physicians use this technique because that is how they were trained. There is no advantage of using flushing over not using flushing on pregnancy rates, but flushing may help to make sure that an egg is either retrieved or not present, especially if there are only few follicles as occurs with poor responders. The downside of this techniques is that is lengthens the retrieval procedure and so more sedation medication is required.

If the egg within the follicle has matured, and assuming that there was an egg within the follicle because not all follicles have eggs, the egg releases from the follicle wall and is floating within the follicular fluid. The exact physiologic process is more detailed than can be explained here, but suffice it to say that the egg is surrounded by a layer that is congruent with the wall of the follicle. As it matures that connection slowly gets pinched off and the egg is released from the wall. If the egg does not reach maturity, it will usually stay attached to the wall. That is why it is important for the physician to determine when is the appropriate time to trigger the follicle with HCG and schedule the aspiration/retrieval. This is another place where the “art” of IVF comes into play and experience plays an important role. Usually once the appropriate follicle size has been reached, the trigger is scheduled so that it is 34-39 hours prior to the time of the retrieval. Most clinics will schedule the retrieval to be at 36-37 hrs.

So by aspirating the follicular fluid, the egg is retrieved from that follicle. The physician will work on one ovary at a time and aspirate each follicle on that side. Once that is completed, then he or she will move to the second ovary and aspirate all the follicles on that side. The follicular fluid with the egg is aspirated, using a specialized aspiration machine with a low aspiration pressure, into a tube that has been prepared with a special culture media. A special 16 or 17 gauge aspiration needle is also used. As the needle is placed into the follicle, the end of the needle can be seen via the ultrasound as a bright echo. This allows the physician to know where the needle tip is at all times to prevent injury to other structures.

The aspirated fluid, collected in a test tube (hence the name “test tube baby” ) is then passed to the embryologist. The embryologist empties the fluid into a small plastic dish and looks for the egg using a high powered microscope. Some of the tubes will not have an egg within because either the egg did not mature and release from the follicle wall, or there was no egg within the follicle i.e. the follicle was empty. Once an egg is identified, the embryologist will move it into a special petri dish or other prepared dish with culture media. This is the dish that the eggs will stay in as it develops into an embryo. The eggs will then be placed into an incubator that has a set temperature, humidity and gas content within so that there is a stable and idealized environment for embryo growth. Fertilization is then the next step in the process.

In the meantime, the patient is awakened, most don’t remember anything that has occurred and enjoyed a short sleep, and moved to a recovery bed or returned to her recovery area. My clinic has individual rooms where the patient is prepared for the procedure and then returned to for her post-procedure care. Many clinics have an open recovery room area, and each patient is separated by a curtain. She is then closely watched by a nurse for 30 minutes to 1 hour to make sure that the sedation has cleared her system, that she remains stable and that there are no signs of any complications. She can take fluids orally at this point (we don’t allow food or drink prior to the procedure).

Once she has met criteria for discharge, she is allowed to go home. My criteria for discharge is that she will need to be able to take and keep down oral fluids, that her vital signs, especially the pulse, remain stable and within normal limits, that she is able to sit upright without getting dizzy and that she can urinate prior to leaving the recovery area. Because we place an intravenous catheter and run IV fluids in our patients, she will receive sufficient fluid to have an urge to urinate by the end of her stay. Most patients will be able to walk out of the clinic on her own after this procedure. From a pain perspective, there is some cramping that occurs immediately after the procedure, but by 30 minutes it is mostly gone. It usually does not need anything more than a warm pad on the stomach or mild nonsteroidal pain medication to relieve the pain. Most patients will not need a pain medication prescribed when they go home. Patients are directed to remain at very light activity, what I call “couch potato rest”, for the duration of the day. They do not need to remain in bed, and I do not encourage it. They should not engage in any strenuous activities, even long walks, or intercourse for 24-48 hours. I usually will prescribe antibiotics for a short course to reduce the chances of pelvic infection, but not all clinics do this. It is also at this point that patients will start their progesterone supplementation which starts the luteal phase of the endometrium in preparation for implantation.

We will continue this discussion soon with the next installment, "Step Five: "Fertilization". Thank you for joining me today! Edward J. Ramirez, M.D. F.A.C.O.G. Medical Director, Monterey Bay IVF Monterey, CA http://www.montereybayivf.com/

A Step By Step Guide To The IVF Process: Step Two -- Follicle Growth And Egg Maturation

Dear Readers:

This is the third part in the series I have begun to help answer what In Vitro Fertilization (IVF) is and how it works with my world-wide Blog audience. What you read here is what I also provide my patients with on a daily basis. I plan on going into some detail but in a way that is understandable to the normal (lay) audience, and not the medical or scientific one. I also hope that this will not only clarify what you will go through, but explain why things are done a certain way and what the goals of each step are. I also want to convey that IVF is actually a replacement for some of the “natural” steps required to get pregnant and not some miraculous high tech fertility treatment that gets patients pregnant artificially, as many think it is. It is somewhat of a miracle that we can do as much as we can, but there are still lots of things/steps that we cannot do or influence. I hope this discussion will benefit you. This series will be posted over the next few weeks in installments.

STEP TWO: FOLLICLE GROWTH AND EGG MATURATION

Under the influence of FSH (follicle stimulating hormone), dormant follicles within the ovary start to grow. Measurement of the dormant follicle number is called the “antral follicle count (AFC)” and also measured by the “Anti-Mullerian Hormone (AMH)”. Both these measurements are used to give one an idea of the ovarian capacity to be stimulated, also known as ovarian reserve, similar to the FSH level. They are additional indirect measurements. Many physicians and patients believe that these two measurements actually tell them how many eggs are left within the ovaries, but that is too broad an interpretation. We do not have the technology to know how many eggs are present without doing a careful dissection of the ovaries. So these are indirect measurements that serve to give warning about your fertility. Their only use is to help predict, as much as possible, whether the ovaries will yield many follicles upon the hyperstimulation that occurs with giving increased amounts of FSH.

So the real interpretation of a low AFC or AMH is that there might be a lower number of follicles produced, and consequently less eggs retrieved. As explained previously, these are additional measurements of “ovarian reserve.” They only predict success from a statistical point of view because part of how IVF enhances your chances of fertility is by increasing the number of eggs that are available for fertilization and hence the number of embryos and hence the increased chance of finding the perfect embryo that will lead to a pregnancy as explained in the previous segment. It is a total misunderstanding or misinterpretation to say that a low AFC or low AMH indicates that you are infertile, that your ovaries won’t stimulate or that you won’t have good eggs! Taken together with an elevated FSH, these measurements serve as red flags from a time point of view. It means that you may not have as much time to get pregnant using your own eggs as you might have thought. Since we cannot predict when you will run out of time, time becomes a critical consideration.

Currently, transvaginal ultrasound is used to monitor the follicular growth by simply measuring the follicles. This measurement is usually an average diameter taken from a horizontal and vertical measurement of the follicle and reported in millimeters (mms). As the ovary is stimulated with FSH, some of the follicles will grow. Follicles grow approximately 2 mms per day so there is some predictability of when the follicles will reach the appropriate size for ovulation or retrieval. As the follicle expands, Estradiol hormone is produced in increasing amounts by the growing follicle and so estradiol levels can be monitored to also help determine progress as well. With IVF, the goal is to have 15-20 total follicles and estradiol levels between 2000-4000. Each mature follicle will produce approximately 150-250 of estradiol. In IVF, we want to keep the estradiol level at less than 4000 because if there are more than 20 growing follicles and the estradiol level goes above 4000, there is an increased risk for an illness called “ovarian hyperstimulation syndrome”. That is a whole other topic so it won’t be explained here. Suffice it to say that OHSS has the potential to cause death in its worst form. A competent physician with experience doing IVF will take appropriate precautions to prevent this from occurring.

It is known that the follicle has to reach an average diameter of a minimum of 15 mms for the egg within to be mature. We cannot see the egg because it is microscopic size. Therefore, maturation is assumed by the size of the follicle, as has been shown in early IVF studies. With most IVF clinics, a follicle is deemed to be mature size and appropriate to trigger once it has reached at least 18 mms, but it can be as low as 15 mms based on previous studies. Because the follicles will grow unevenly, meaning there will be some that grow faster and some that grow slower, most physicians will trigger with HCG when the largest 2-4 follicles reach maturity size, or when the highest number are between 15-24 mms. My preference is for the larger follicles to be 20-24 mms which I have decided to use based on my long term experience. I don’t necessarily trigger when the largest ones reach that size but, rather, I want to get as many follicles into the mature stage as I can without losing the larger ones or have too many smaller ones. The problem with smaller sized follicles is the eggs within them will not have had adequate time to mature and so will be unusable. Also, follicles that grow to over 24 mms tend to have eggs that are over-mature and therefore not viable. Once the majority of the follicles reach a size of 20-24 mms, then you are ready for the “trigger” shot. The decision of when to give this shot is determined by the experience of the doctor part of the art of IVF. If given too soon, you may lose eggs because they will not be mature. Too late and you may lose them because they will be over-mature. The goal is to try to get the majority number of mature eggs as possible because only mature eggs will fertilize.

Until the trigger shot is given (or the body goes through an LH surge if allowed to occur naturally) the egg within the follicle does not go through its final phase of maturation, meiosis stage 2. Eggs within the follicle are usually in the “germinal vesicle (GV)” stage. Once stimulation occurs, they then go through meiosis phase 1 (M1) and then are mature at meiosis phase 2 (M2). In the natural reproductive process, the “trigger” occurs under the influence of a hormone called LH (luteinizing hormone) and is known as the LH surge. This is what is being checked when you use an ovulation detector kit. There is a sudden rise in the LH hormone which then signals the ovary to begin the ovulation event.

In IVF, HCG (human chorionic gonadotropin) hormone, which is chemically similar to LH, is substituted for the LH to make the eggs go through their final maturation phase and begin the process of ovulation. There are three sources for this medication:

(1) Urinary HCG extracted from human urine,
(2) Recombitant HCG (synthesized HCG) and
(3) Lupron, another drug that has a similar chemical structure to LH.

Lupron can only be used if you are on an antagonist protocol, with Ganerelix or Cetrotide, and not in a long Lupron protocol. This trigger shot will also cause the ovary to begin the ovulation process but because we don’t want the ovulation to occur, and thereby lose the eggs into the pelvis, the egg retrieval procedure is timed to occur before ovulation will take place. This is usually scheduled for 35-36 hours from the trigger shot.

We will continue this discussion soon with the next installment, "Step Three And Four: Egg Retrieval". Thank you for joining me today!

Edward J. Ramirez, M.D. F.A.C.O.G.
Medical Director, Monterey Bay IVF
Monterey, CA
http://www.montereybayivf.com/

A Step By Step Guide To The IVF Process: Step One -- Stimulation

Dear Readers,

This is the second part in the series I have begun to help answer what In Vitro Fertilization (IVF) is and how it works with my world-wide Blog audience. What you read here is what I also provide my patients with on a daily basis. I plan on going into some detail but in a way that is understandable to the normal (lay) audience, and not the medical or scientific one. I hope that this will not only clarify what you will go through, but explain why things are done a certain way and what the goals of each step are. I also want to convey that IVF is actually a replacement for some of the “natural” steps required to get pregnant and not some miraculous high tech fertility treatment that gets patients pregnant artificially, as many think it is. It is somewhat of a miracle that we can do as much as we can, but there are still lots of things/steps that we cannot do or influence. I hope this discussion will benefit you. This series will be posted over the next few weeks in installments.

STEP ONE: STIMULATION

As explained in the natural process, the first step in your body is for the hypothalamus and pituitary to send a hormone to the ovary to stimulate the growth of a follicle and maturation of the egg within.

The hypothalamus sends a hormone called GnRH or gonadotropin releasing hormone to the pituitary. This in turn, causes the pituitary to give off follicle stimulating hormone (FSH) and a little luteinizing hormone (LH). For now, I won’t go into detail regarding LH since it is not as important in this stage of the process. The FSH, or follicle stimulating hormone, stimulates the growth of a follicle, hence the name. The ovaries already have all the follicles they are going to have from birth. These follicles are in a dormant state until they are stimulated. In a natural cycle, several follicles are stimulated but only one is designated to grow to ovulation. The FSH goes through the blood stream and makes its way to the ovary. The ovary then picks up this hormone from the blood. It then processes the hormone and a follicle grows causing the production of estradiol and progesterone, and maturing the egg within. The egg is normally in an immature state in the dormant follicle.

In the IVF process, we take over the function of the hypothalamus and pituitary. In fact, we shut down the natural process so that we can control how the process goes and to help with timing. Timing is critical in IVF, as it is in the natural process. Many programs use birth control pills to shut down the ovaries and thereby shut down the hypothalamic-pituitary axis. Some clinics use leuprolide acetate or Lupron, Synarel or a similar drug, to shut down this axis. These drugs are known as GnRH (gonadotropin releasing hormone) agonists which is essentially adding GnRH but the brain monitors the levels of this hormone and if it reaches a certain threshold, shuts down production in the hypothalamus. Using Lupron from the luteal phase of the previous cycle is known as the “long protocol”. Some programs will go into IVF directly from an natural menstrual cycles and this is sometimes called “Natural cycle” IVF.

As I was explaining, in the IVF process we take over this step by giving FSH and LH hormone directly. These are known as injectable fertility drugs, but in actuality are not “fertility” drugs but merely the hormones your body would naturally produce to induce follicle growth in the ovary but at a higher dosage. So in reality, these drugs don’t increase your fertility or make you more fertile, they actually just give you more of an opportunity to become pregnant. Some of the medication used in IVF, such as Gonal-f or Follistim are now recombitant, or genetically produced FSH (in the old days, all FSH used to be natural FSH that was extracted from elderly women’s urine). These medications are pure FSH and have no LH within. There are other medications such as Pergonal, Menopur, Repronex that contain both FSH and LH. These are still derived from urine. Some clinics will use only FSH but most will use a “mixed” protocol, meaning they use both an FSH only drug in combination with an FSH/LH drug taken together.

The amount of medication given is what determines how many follicles your ovaries grow, and is dependent on how aggressive your doctor wants to be, i.e. how many follicles they want to try to get, and how well he/she thinks your ovaries are functioning or going to respond to the stimulation. We call the latter “ovarian reserve”. A younger patient will usually, but not always, have a very good ovarian reserve and therefore require less medication, whereas as a woman ages, her ovaries become more resistant or less likely to pick up the FSH from the blood, i.e. decreased ovarian reserve. Logically you can see that if the ovaries are more responsive, less medication is required and vice versa. The best way to picture this, as I explain to my patients, is to imagine a golf “wuffle” ball. If you don’t know golf, this is a practice ball with lots of holes in it so that it doesn’t fly far. Imagine that all the holes are open and you put the ball in a bowl of fluid (which is the FSH). The wuffle ball readily admits the fluid into its center. Now imagine that you block off most of the holes in the ball. You can see that less fluid gets into the ball (you also have to imagine that you have a time limit as to how long the ball gets to sit in the bowl of fluid). That is ovarian resistance. No matter how much drug you give, the ovary will only pick up as much FSH as it can and thereby only stimulate as well as it is going to stimulate. There is no technology that can change this. That leads to a lower ovarian response to the stimulation, and less follicles and eggs to work with. It is called “ovarian resistance” once stimulation has been attempted and only a few follicles grow. That is different from “ovarian reserve” which is the anticipated ovarian response or ovarian response potential before stimulation. “Ovarian resistance” is what you see once the stimulation is done and the ovary does not stimulate well.

The stimulation step is important because part of the success of IVF is an enhanced statistical chance by having lots of eggs to work with. Take for instance, if you have one dice and you want the number five. You have a 1 in 6 chance with each roll of the dice. Of course, your chances increase with rolling the dice more times, which is a different statistical chance and the statistic that changes as you attempt IVF repetitively. But taking just one roll into consideration, as in one IVF cycle, your chance is 1 in 6. Now, if you add three, four or five dices to that one roll, you can see that you have increased your chances 3, 4 or 5 fold. That is the same with each IVF cycle. In a natural cycle, you give off only one egg, so if that egg doesn’t go through each step perfectly, you don’t get pregnant. IVF increases your chances of pregnancy by accomplishing more of the steps of the process for you, but more importantly, you still need to have a perfect egg that forms a perfect embryo. If you only have one egg, the chances of having a perfect egg are significantly decreased. It increases by having more eggs to work with. That is how IVF increases your chances of pregnancy statistically. So the goal of stimulation is to try to maximize the number of eggs that you have available in order to increase your chances of getting/finding the perfect egg/embryo.

Now there is a caveat to this. You don’t necessarily want too many eggs because over stimulation can not only cause a major illness, but the egg quality may suffer. This is where the “art” of IVF lies. It is up to the doctor to try to make an educated guess as to how much stimulation would be ideal for each patient. Under-stimulate and you decrease the chances. Over-stimulate and you also decrease the chances, as well as, risk making the patient sick. Doctors get better at making this decision through experience. And this is part of what makes each doctor and each clinic different.

We will continue this discussion soon with the next installment, "Step Two: Follicle Growth and Egg Maturation". Thank you for joining me today!

Edward J. Ramirez, M.D. F.A.C.O.G.
Medical Director, Monterey Bay IVF
Monterey, CA
http://www.montereybayivf.com/

A Step By Step Guide To The IVF Process: Overview

Dear Readers,
I get many  many questions regarding what In Vitro Fertilization (IVF) is and how it works that I thought I would share the information with my world-wide Blog audience. What you read here is what I also provide my patients with on a daily basis. I plan on going into some detail but in a way that is understandable to the normal (lay) audience, and not the medical or scientific one. I hope that this will not only clarify what you will go through, but explain why things are done a certain way and what the goals of each step are. I also want to convey that IVF is actually a replacement for some of the “natural” steps required to get pregnant and not some miraculous high tech fertility treatment that gets patients pregnant artificially, as many think it is. It is somewhat of a miracle that we can do as much as we can, but there are still lots of things/steps that we cannot do or influence. I hope this discussion will benefit you. This series will be posted over the next few weeks in installments.

OVERVIEW:
Before I begin explaining each step, let me give you an overview of IVF. As I mentioned earlier, IVF or "In Vitro Fertilization" is actually a replacement for the natural steps your body would go through in order to get pregnant, and it still relies on many of those natural steps to occur before you become pregnant. “In Vitro” means in the laboratory versus “In Vivo” which means in the body. As I’ll explain, IVF is not all done in the lab. Some parts of the process still are required to be in the body, so in actuality, it is both an “In Vitro” and “In Vivo” procedure.

There are basically nine steps that your body goes through in order to achieve a pregnancy:

(1) Your brain (hypothalamus and pituitary) sends a signal to the ovaries to stimulate the growth of a follicle and maturation of the egg within.

(2) The designated follicle grows, and the egg matures, until it reaches a critical size, whereby there is an LH surge to induce ovulation.

(3) The follicle surface ruptures and an egg is expelled with the rush of fluid within (ovulation) and enters a space behind the uterus called the culdesac, the lowest point in your abdomen.

(4) Through fluid motion (this part is not exactly known so it is my personal belief that this is how it happens), the egg contacts one or the other fimbria of the tube, which is hanging into the culdesac in its natural position, and now lies within this puddle of fluid. The egg is then brought into the tube by the fimbria and tubal motility.

(5) The egg moves into a part of the tube where, hopefully, the live sperm are waiting to attach to the egg, and then fertilization occurs.

(6) The fertilized egg slowly moves down the tube, dividing and forming into a blastocyst.

(7) The blastocyst then enters into the uterine cavity and settles there.

(8) The inner portion of the blastocyst then hatches out of the shell and attaches to the uterine lining.

(9) The uterine lining then engulfs the embryo, which is known as implantation and at this point bHCG begins to be produced.

These are the steps that your body goes through to get pregnant, but does not do it exactly or perfectly each month. That is why it may take several months before a human woman gets pregnant. IVF is basically accomplishing most of these steps for you, NOT doing some artificial process. Yes, it is not within your body, or at least some of it is not, but the same processes have to occur. If you know and understand IVF you can see that IVF basically accomplishes steps 1-7. Two steps then have to occur naturally for pregnancy to occur. So as you can see, IVF is still basically a “natural” process because it still relies on natural processes within your body.

In other words, we give fertility drugs to stimulate the ovaries to grow and mature eggs but the ovaries still have to pick up and process these hormones on their own, and growth and maturation of the eggs still have to occur naturally. We can put the egg and sperm together but fertilization still has to occur by itself. Even ICSI (intra cytoplasmic sperm injection) is only putting the sperm into the egg. The actual fertilization process, the merging of the egg nucleus and sperm nucleus, among other processes; still have to occur on their own. We cannot make that happen. We can put a grown embryo into the uterus but we cannot make it hatch out of its shell, attach to the uterine lining or make the lining engulf the embryo (implant). All of these steps are left up to nature or, as I tell my patients, are in God’s hands and the way He reminds me that I am but His humble servant. This keeps my head and ego from becoming too big!

Many patients are devastated when an IVF cycle fails, because they have the false belief that it is the ultimate and perfected technological way to become pregnant, and therefore works every time. It is certainly more technological but not even close to being the ultimate or perfect method, and it doesn’t work every time. For that reason we cannot achieve 100% pregnancy rates, and much research and technological advances still need to be developed before we will get there. Make no mistake, however, we have improved greatly since the first IVF success with Louise Brown, but that took years to occur as well.

Sixteen years ago when my wife and I did IVF, she was 37 years old, and her statistical chances were about 12-15% but now a 37 year old in my center has a 65% chance of pregnancy per cycle. We have improved greatly and come a long way. We can now help a couple acheive a pregnancy where previously there would have been no other option but adoption. IVF is certainly better than trying naturally because more steps are accomplished, whereas in natural cycles, the body does not always do each and every step correctly. For example, ovulation may occur but the egg may never find the fimbria so that month pregnancy will not occur. Just to put things in perspective, a 37 year old has a 5% chance of pregnancy per month of trying by natural means. When trying naturally, women have to keep trying for several months before a pregnancy occurs. In fact it will take 85% of women under 30 years old 8 to 12 months to achieve a pregnancy. In the same way, because IVF is just replicating the process, it can take several attempts before the body does its part of the process correctly. In my center 55% of patients (not adjusted for age), achieve pregnancy in their first attempt. Most patients will be pregnant by three attempts rather than the 12 months it may take to achieve a pregnancy naturally.

We will continue this discussion soon with the next installment, "Step One: Stimulation".

Thank you for joining me today!

Edward J. Ramirez, M.D. F.A.C.O.G.
Medical Director, Monterey Bay IVF
Monterey, CA
http://www.montereybayivf.com/