This past summer, Dr. Herbert and I had the opportunity to travel to Barcelona, Spain for the annual meeting of the European Society for Human Reproduction and Embryology (ESHRE). Though largely attended by Europeans, this scientific meeting draws physicians, embryologists and scientists from around the world to discuss their research, attend courses and lectures, and discuss the latest topics in our field.

Here are some of what I consider the highlights of the meeting:

Outcome of 1267 Children after Frozen Embryo Transfer – Study from Denmark

Control group: Fresh IVF pregnancies

Only 14% were twins

They compared 957 frozen embryo singletons with about 10,000 fresh IVF singletons

No increase in neurological problems or malignant diseases on FET babies.

No differences were seen when IVF or ICSI-derived frozen embryos were compared.

Results similar to prior Swedish study showing better outcomes for FET babies.

Why a better outcome? The authors postulated that patients conceiving with FET were more likely to be good prognosis patients.

Three years of clinical application in human oocyte vitrification (freezing): high survival rate and healthy deliveries (from Rome)

3138 unfertilized eggs were frozen between 10/04 – 10/07.

They reported on 295 cycles with planned embryo transfer – all patients were less than 40 years old. The patients underwent programmed endometrial preparation using a GnRH agonist (like Lupron) and oral estrogen and vaginal progesterone.

770 unfertilized eggs were thawed, 98.9% survived the thaw. The eggs were injected with sperm 2 hours after thawing and the embryos were transferred on Day 3.

Results: Avg. # embryos transferred = 2.3

Clinical pregnancy rate = 27.8%

Implantation rate = 13% per embryo, 11.3% per thawed egg. That is, about 11% of the eggs thawed resulted in a viable gestation.

58 deliveries of 63 babies, mean birth weight = 2930 grams

They experienced no congenital malformations at birth.

Then, the most controversial paper presented by Dr. Norbert Gleicher, an RE from New York.

The title: “In contrast to prevalent opinion, twin pregnancies after fertility treatments are medically, ethically and economically desirable outcomes.”

His arguments to support this opinion:

Most couples want to have more than one child. Therefore, they will need to undergo two pregnancies of two separate singletons vs. one pregnancy of twins to have two children. He argued that twins born after ART have much better pregnancy outcomes (by 30-50%) than spontaneously-conceived twins. He also argued that the accumulated costs and risks to mother and babies are higher with two singleton than one twin pregnancy.

Despite these intriguing arguments, this paper was hotly debated and essentially disavowed by the European ART community. Europe has led the way in legislating for avoidance of twins. In fact, in Denmark, if a woman has twins after the transfer of more than one embryo using IVF, she incurs any neonatal costs out of pocket.

Corifollitropin: a modification of Follistim to make it a once-a-week injection.

As most people know, the medication we most commonly use for fertility treatment, Follistim, is pure human FSH, manufactured using recombinant DNA technology. The company that makes Follistim, Schering Plough, is working towards FDA approval of a modified version of Follistim, called Corifollitropin, that will make the drug very long-acting. It may be possible to only take one injection per week!

A symposium at ESHRE presented information from studies underway in Europe and USA. Corifollitropin is not in clinical use yet, even in Europe, but will be very soon.

For those of you interested in the details, Corifollitropin is the recombinant FSH molecule + 22 C-terminal peptides from beta-hCG, It does not bind to the LH receptor.

This modification lengthens the half-life of Follistim from 22-34 hours to 60-74 hrs for Corifollitropin. After injection peak levels are reached in 2 days then slowly levels decline. The recommended regimen will be one dose per week, starting at baseline, switch to daily recombinant FSH after that.

	Carolyn Givens, M.D. was the first in San Francisco to successfully initiate a pregnancy using intracytoplasmic sperm injection (ICSI). She currently co-directs the Bay Area Pre-Implantation Genetic Diagnosis Program (PGD) and is director of PFC’s PGD program.
	Carl Herbert, M.D. was instrumental in the development of one of the first assisted reproductive technology programs in the United States and has been performing IVF longer than any physician in the Bay Area.

Question: A friend of mine recently conceived a couple of months after two failed IVF cycles. Did she really need IVF in the first place or did the IVF change things to make it more likely she would get pregnant on her own later?

Answer: For some couples, IVF is necessary because the woman’s tubes are blocked or because the sperm count is drastically low. For these patients, IVF is probably the only way they are going to conceive. For the rest of our patients, those with endometriosis, mild male factor, decreased ovarian reserve, age-related, or unexplained infertility, there is some chance of conception, however low it is. For these patients, IVF is a way to boost (often dramatically) the chances of conceiving sooner than later.

For example, for a couple that has unexplained infertility of one to two years’ duration, the statistical chances that they are going to conceive on their own are probably in the range of 3% per month. Depending on the woman’s age, IVF could increase that to 20-50% per month of treatment. But even if she doesn’t happen to get pregnant with IVF, and the couple continues to try on their own, their chance of conception returns to that 3% per month, so they may conceive, even after a failed IVF attempt. There is no reason that the IVF itself should make that couple more likely to conceive later.

An Example X-Ray of a normal HSG	An example X-Ray of an abnormal HSG

Infertility due to blocked fallopian tubes was a common cause of infertility in the 1970’s and 1980’s. Some textbooks from that era quote an incidence as high as 25% of all infertility causes. At Pacific Fertility Center in 2005, only 10% of our in vitro fertilization patients were noted to have a tubal factor contributing to their infertility. Fallopian tube damage is most commonly due to prior infection with a sexually transmitted disease such as gonorrhea or Chlamydia. Most chlamydial pelvic infections are relatively asymptomatic and may go unrecognized; therefore many patients with tubal obstruction are unaware they have a tubal problem. Better safe-sex practices and improved screening of young women are possible factors for the lower incidence of tubal disease we are seeing, at least in our Bay Area infertility population.

Even though there is less tubal factor infertility these days, if there is a tubal obstruction, the course of fertility treatment becomes quite definitive: in vitro fertilization. No other treatments, including surgery, are likely to result in a healthy intra-uterine pregnancy. Therefore, we are still advocating some type of screening test for tubal factor in the evaluation of infertile couples.

There are two common ways to determine whether there is tubal obstruction. One is surgery, where dye is passed through the cervix, uterus and tubes, and there is direct visualization of the flow of the dye out the ends of the tubes into the pelvis. The other is the HSG, or hysterosalpingogram. The HSG is an X-ray procedure that involves placing into the cervix a small flexible catheter with a balloon around the tip to hold the catheter in place and close off the cervical opening. Radiographic contrast dye is then instilled into the uterine cavity, using a syringe attached to the tube. Under X-ray visualization, the dye is tracked into the uterine cavity and into the tubes. Pictures are taken during this process to document the shape of the uterine cavity and whether or not the dye enters and flows through both tubes into the pelvis.

HSG procedures are usually performed by radiologists; however, if there is difficulty placing the catheter securely into the cervix, the radiologist may ask the patient’s gynecologist to assist. This test is valuable in determining tubal blockages, but it has some disadvantages. It is very important to get the balloon properly inflated in the cervix to keep enough pressure on the fluid (no back flow into the vagina) so it will enter the fallopian tubes. Unfortunately, this pressure on the walls of the uterus can cause the uterus to contract, causing the patient to experience significant cramping. For this reason, it is recommended the patient take 2 or 3 ibuprofen prior to the procedure.

In some cases, the pressure is enough to cause the smooth muscle walls of the fallopian tubes themselves to spasm, blocking any dye from entering the tube. Sometimes the dye flows so easily through one tube that there is not enough pressure generated to get the dye to fill the other tube. These are some of the drawbacks of the procedure. This is why, even when we get a report of one-sided tubal obstruction, we are often skeptical that this is really due to some abnormality of the tube.

Although there are some false positives associated with this test, if the dye fills both tubes and does not flow out the ends of the tubes, this is highly suggestive of true tubal obstruction. In this instance, IVF is indicated.

At Pacific Fertility Center we aim to help our patients build a healthy family. To build healthy families, maximum pregnancy rates are a goal, but maximum pregnancy rates must be balanced by consideration of risk, the chance of an adverse outcome. High pregnancy rates with minimal risk is PFC’s goal.

The risk of multiple pregnancy has increased as fertility therapy has improved. The wider use of gonadotropins in the 1990s to induce ovulation of multiple follicles, as well as the use of more effective laboratory and clinical IVF methods, resulted in production of more and healthier oocytes and more embryos, and increased the chances of multiple pregnancy. The very dramatic improvement in success rates over this time period resulted in many more children being delivered after fertility therapies, but also more twins, triplets, and higher order multiples.

Over the last twenty years, the incidence of multiple birth has increased nationally. According to the National Vital Statistics Report and the March of Dimes, the incidence of twins has increased by two-thirds, and the number of triplets and quadruplets has increased four-fold since 1980.

It is thought that about one-third of multiple pregnancies arise because women are waiting until later in life to conceive; age is a well-known risk factor for multiples. Another third arise from use of ovulation induction with gonadotropins (Pergonal, Follistim, Gonal-F, Repronex) alone. Less than one fifth of multiples are from assisted reproduction techniques (IVF and related procedures). Assisted reproduction in 2003 accounted for 18% of multiple pregnancies, 16% of twins and 44% of triplets ¹.

The risks to the children of multiple pregnancy are numerous. Low birth weight and very low birth weight are increased in children born as multiples. The chance of low birth weight (<2500g) is increased 8 times in twins. Cerebral palsy is increased 4 times, neonatal death risk by 7 times ^{2, 3}.

The risk to the mother from multiple pregnancy is also increased. Pre-eclampsia, high blood pressure, preterm labor, and premature rupture of membranes are all more common with multiple pregnancy ⁴ .

Multiple pregnancy is also expensive. It is estimated that twins alone cost the healthcare system some $600,000,000. There is clear evidence of an increase in parenting stress and divorce in families of multiples ^{5, 6} .

The need to assure our patients of the highest quality care requires that we bear this in mind – the healthiest pregnancy is a singleton pregnancy.

Pregnancy requires the cooperation of sperm and egg, accurate transcription of the early genetic code in the developing embryo, a fertile spot for attachment to the mother in the uterus, and a route for getting there. All other factors being equal, pregnancy rates almost double when two embryos are transferred instead of one, and increase again when a third and fourth embryo are added. The desire for high pregnancy rates has driven a desire for more embryos to be transferred ⁷ .

Improvements in insemination technique, embryo culture methods, and transfer efficiency have added substantially to pregnancy rates. Each embryo transferred today has a considerably higher chance of producing a pregnancy than an embryo transferred twenty years ago. Such improvements have enabled us to think about ways to reduce the risk of multiple pregnancy by transferring fewer embryos.

The development of blastocyst (day 5 embryo) culture techniques allows the selection of high quality embryos for transfer. The blastocyst stage requires advanced incubation techniques with low oxygen incubators and specialized culture media. A tight quality control system is also required. The blastocyst stage is a more advanced stage in which the genetic code of the embryo is fully activated and working. Only the healthiest of embryos can move to the more advanced stages, allowing selection of the best embryos for transfer.

In 2006 the ASRM published guidelines for number of embryos to transfer:

These guidelines encourage all of us to transfer ‘just enough’ embryos to achieve pregnancy.

Pacific Fertility Center has pioneered techniques of transferring fewer embryos. Last year, in 2007, our program of single embryo transfer in oocyte donation recipients produced a 66% pregnancy rate. The multiple pregnancy rate in this group was minimal. Utilizing a single embryo, two-thirds of patients were able to conceive a singleton pregnancy. This pregnancy rate was very similar to the overall pregnancy rates regardless of the number of embryos transferred.

Today half of our patients using oocyte donation elect to transfer a single embryo. Single embryo transfer is not always possible. Our criteria include age and embryo quality. A young woman (under age 35) with high quality blastocyst stage embryos and a healthy uterus can reliably transfer a single embryo and achieve high pregnancy rates. An older woman (over 40) may need to transfer 3 or more embryos to achieve a good pregnancy rate. Because of the higher number of embryos transferred, the risk of multiple pregnancy remains higher in these older age groups⁹ .

Pacific Fertility Center is very pleased to offer these techniques of single embryo transfer as some of the best and most advanced fertility treatment technology available. We are moving closer to our goal of growing families, one healthy baby at a time.   Philip Chenette, MD

1. Martin, Births: Final Data for 2003. National Vital Statistics Reports, volume 54, number 2, 2005
2. Scher, Ped Res, Vol. 52:671-81, 2002
3. Rutter, J Child Psychol Psych, Vol. 44:326-41, 2003
4. Pinborg, Human Reproduction, Vol. 18:1234-43, 2003
5. Griesinger, Hum Reproduction, Vol. 19:1239-1241, 2004
6. Glazebrook, Fertil Steril, Vol. 81:505-11, 2004
7. Paulson RJ, Fertil Steril., Vol. 53:870-874 , 1990
8. Fertil Steril, Vol. 85, Suppl. 4, 2006
9. Pacific Fertility Center 2007 IVF Statistics

As a lesbian couple, we were aware that getting pregnant might be a challenge and might require medical intervention, but decided to try at home anyway.  Since Jean is older it made sense for her to carry first.  In 2002, we began the process of trying to conceive with our known donor.  We had a few challenges to overcome. Our donor was from out of state and we had to use a shipping kit designed by University of Chicago Andrology Lab to maintain the viability of the sperm.  We hired a midwife to come to our home, clean the semen sample and do the insemination.  In 2004, after two years of trying and many dollars spent, it became apparent that we were not going to be successful on our own.

We spoke to our OB/GYN who recommended that we work with a fertility specialist.  On a recommendation from a Pacific Fertility Center staff counselor, Peggy Orlin, we contacted Dr. Eldon Schriock at PFC.  Though the initial paperwork and set up seemed daunting, we were able to complete the required items quickly and were ready to start fertility treatment with Dr. Schriock in March 2005.  Jean was set to do the “Clomid challenge” test on our first attempt.  With new FDA regulations looming in May 2005, we felt we had limited time to get Jean pregnant with our current donor so the pressure was on.  Although the PFC staff was not initially familiar with our shipping kit, they were more than willing to work with it and help us with the logistics.  Jean had a fortunate experience with Clomid and on April 15, 2005 with 3 good follicles we completed our first IUI with PFC.  Two weeks and 3 positive pregnancy tests later, we confirmed that we were in fact going to have a baby.  It was hard to believe that after so many years and tries it was actually happening.  Now 3 years later we have a beautiful and fun two year old girl named Logan.

When Logan was 5 months old, there was an accident in my family that gave us pause.  We realized life is short and you never know what is in store for you around the next corner .We decided to begin the process of trying to get Marni pregnant. In May 2006 we made the decision that we would begin the process at home, but needless to say, we were unsuccessful. After 6 months we would again meet with Dr. Schriock and his fabulous team of nurses and doctors.    Because of our history with PFC, we were able to quickly begin the process and get started trying to achieve pregnancy at PFC.

With the new FDA regulations now in place we had a host of new hoops to jump through. Once we cleared the list of hurdles, we began our attempt to get Marni pregnant.  After many different fertility treatments (Clomid, Letrazole, and Follistim), three different PFC doctors (Dr. Schriock, Dr. Ryan and Dr. Givens) all suggested that if we were committed to our donor then we should seriously think about IVF as an option because of the quality of his frozen/thawed sperm.  In October 2007 we began the IVF process.  Though there was a lot to manage and keep track of (when to give shots, appointments, blood tests, etc.) we never felt alone.  The PFC doctors, nurses and staff were always available for a phone conference to answer any questions or concerns.  In late November 2007 we completed IVF – the egg retrieval and embryo transfer process.  Four embryos were implanted out of the seven that fertilized.  In December 2007, two weeks later, we received the positive blood test result and were ecstatic.  Unfortunately, within days of the positive pregnancy result it became clear that this was not going to be a viable pregnancy.  Marni had apparently been pregnant with twins. She miscarried the first embryo and had to undergo not only the abortion pill, but a subsequent D&C to remove the second gestational sac.  Dr. Schriock and all of the staff, nurses and other doctors were available for emotional support and medical guidance throughout the process.

We completed our second egg retrieval and awaited the fertilization results.  Our hopes were high but we were realistic and knew that anything could happen. As it turned out, Marni’s second round of IVF was unsuccessful. Though the quality of embryos was better than in the first cycle, she did not get pregnant.  We had a few conversations with Dr. Schriock and determined that if she were to continue trying to get pregnant, it would take an ovum donor and a lot of money.  We decided to have Jean try again, because we wanted to be pragmatic and realistic and keep the goal of adding to our family in mind.  Jean is currently under Dr. Schriock’s care and last week she completed a course of Clomid and an IUI.  We are now in the waiting period and are hopeful for a positive result.

Our experience with PFC, Dr. Schriock and all the other staff has been great.  We had a few bumps along the way but the doctors, nurses, office manager and staff responded quickly and effectively.  We always felt at ease to express concerns and ask questions.  Everyone we encountered at PFC has a good understanding of how emotional this process can be and has always been empathetic in their dealings with us.  We never felt uncomfortable as a lesbian couple.  We would absolutely recommend PFC for their cutting edge technology, knowledge and exceptional care during this highly emotional event.

Best Regards,
Marni & Jean

1. A healthy woman in her late 30’s or even in her 40’s, will have the fertility of a younger woman.
   Although it is always better to be healthy, especially when it comes to carrying a pregnancy, the likelihood of conception is tied to the age of a woman’s eggs and is not closely related to her general health.
2. You should have sex every other day during the fertile window.
   For most men, sperm recovery is very rapid. Sometimes when an IVF cycle is done and there are many eggs to fertilize, we ask for a second semen sample. We are often amazed when the second sample, collected just 2 hours after the first sample, has even better numbers. So, rather than attempting to “save up good sperm” by having less frequent intercourse during the most fertile time period, we recommend more frequent intercourse. A home ovulation predictor kit is useful to time sex to ovulation. When using the ovulation predictor kit, we recommend sex on the first day of the LH surge and the next day too.
3. Fertility medications are associated with a higher risk of cancer.
   In the early 1990’s, some concerns were raised that taking fertility medications might be associated with a higher lifetime risk of ovarian cancer. Since then, several studies have been published that did not find this to be true. Because of this thorough and extensive research we feel comfortable using these medications not only on patients, but our egg donors as well.
4. Fertility medications (especially injectable fertility medications) cause women to be emotional wrecks.
   Although Clomid (clomiphene citrate) has well-known side effects related to its anti-estrogen effects, the injectable fertility medications do not tend to cause the same negative mood alterations. These drugs increase estrogen levels, a hormone which tends to have positive affects on mood.
5. Using fertility drugs and getting multiple eggs might use up my future eggs and cause me to go into menopause earlier than expected.
   Humans usually only ovulate one mature egg each month. This egg is contained in the dominant follicle and grows in one ovary or the other. For each dominant follicle that develops in any particular cycle, there are several other follicles/potential eggs available that are also trying to become that dominant follicle. The number of these other “antral” follicles varies from woman to woman and to lesser degree, from cycle to cycle. In general, the number of antral follicles declines with female age. Once the dominant follicle has been selected and the egg ovulated, the menstrual period or a pregnancy begin, and the other antral follicles, undergo programmed cell death, called atresia. The use of fertility medications rescues this group of antral follicles from atresia. For this reason creating multiple mature follicles and obtaining multiple eggs in any one cycle does not use up future eggs. We are simply rescuing eggs that would have otherwise died that month.
6. Having a miscarriage is a good sign that a woman is fertile.
   Approximately 70% of miscarriages are due to abnormal chromosomes (DNA) in the embryo. As a woman ages, more and more of her eggs become abnormal In fact, at age 40, only 1 in 10 eggs on average has normal chromosomes; so a woman at that age may only ovulate one normal egg per year. While a miscarriage may indicate that fertilization and implantation can occur, it doesn’t necessarily mean that overall egg quality is good. Egg quality is the best indicator of the ability to produce a viable pregnancy.
7. Stress is a major cause of infertility.
   There is enough circumstantial evidence to indict stress as a collaborator when it comes to fertility; however, there is very little evidence to convict stress as a major perpetrator. Usually there is some other underlying cause to the problem, even if it is just age-related sub-fertility (decline in fertility due to female age and therefore higher numbers of abnormal eggs). Stress, however, can compound the problem and possibly negatively impact egg quality and uterine lining quality. Look for a new addition to our website, the Domar Fertility Stress Questionnaire, to assess your stress levels.
8. In Vitro Fertilization can help women in their late 40’s and even 50’s to conceive with their own eggs.
   Despite the number of celebrities having babies in their mid-forties and beyond, these babies may not necessarily have been the result of an in vitro fertilization process using their own eggs. While we respect a woman’s right to privacy and their decision not to divulge this little detail, the perception left with the public is that fertility treatments can extend one’s reproductive life. Unfortunately, this simply is not true. There is a very, very low probability of improving one’s success of conceiving after age 43 by using assisted reproduction, unless the woman considers using donor eggs.
9. In Vitro Fertilization success rates are low.
   Across the United States, including patients of all ages, the delivered success rates for in vitro fertilization have risen from about 20% in the mid-1990s to about 35% in the mid-2000s. During this same period, fewer embryos were being transferred to the uterus per cycle and the triplet and higher-multiple pregnancy rates dropped dramatically. Though it may take more than one attempt to conceive, the majority of patients are successful.
10. Very few people ever experience infertility.
    Many fertility patients feel they are the only ones in their circle of friends and acquaintances suffering from infertility. At times, it seems as though everyone else is having a baby. Actually, one in six couples is having trouble with conception, they just may not talk about it. Since they are not pushing a stroller, there is no outward visible sign of their fertility status. When couples decide to share the story of their fertility quest, they often find there are many of their peers experiencing similar difficulties. They discover friends who can not only relate but also provide valuable support.

For patients having their embryos transferred at the blastocyst stage, the grading procedure used to assess the embryos can seem complicated. However, we simply look to see that the embryos are developing normally, are not slowing down, and are preparing for implantation in the uterus.

In the 2 days following fertilization, embryos go through 3 rounds of cell division. The fertilized oocyte divides in 2, these cells each divide again to give 4, and then these divide to give 8. In the resulting 8-cell embryo, each cell should be 1/8 the size of the original oocyte since there is no growth in size, and each cell should be intact and symmetrical. When we assess embryos at this stage, we first count the number of cells and we then assign a grade based on how good the embryo looks. Embryos that have disintegrating or asymmetrical cells are assigned a lower grade.

At this early stage, the individual cells stay together because they are contained within a shell called the zona pellucida. However, as the embryo progresses past the 8-cell stage, dividing to 16 and then 32, the cells attach to each other and cooperate to form a tight ball called a morula. At the morula stage, the cells are pressed so tightly together that individual cells cannot easily be identified or counted. Once the attachments between cells are formed, the cells begin to pump fluid into the center of the ball, giving rise to a tiny fluid filled cavity or cyst. As long as the junctions between cells hold, no fluid can escape from the cyst, and the cyst grows larger as more fluid is pumped in.

These are critical days for the embryo. In addition to forming the central cyst, the embryo is also busy organizing its cells into two distinct populations. As the embryo moves beyond the 8-cell stage, some cells stay on the outside of the ball and some are pushed to the inside. In the typical 16-cell embryo, there are 12 outer and 4 inner cells. At the 32-cell stage, 22 of the cells are outer cells and 10 are inner cells. Creating more outer cells is deliberate, because these cells are needed to maintain the integrity of the cavity as it becomes larger. More importantly however, these cells will become the placenta, and having enough cells to establish the placenta is critical to successful implantation in the uterus. Once the placenta is established, it can feed the inner cells which become the developing fetus.

The appearance of the cyst at the center of the morula marks the next embryo stage, the blastocyst. In assessing the blastocyst, we look at the size of the cyst and the integrity of the outer and inner cells. Depending on the size of the cyst, the blastocyst is referred to as early, expanding or fully expanded. If the cyst has become large enough to cause the embryo to burst through its shell, we call it a hatching blastocyst. Occasionally, we even see fully hatched blastocysts. Hatching is a natural process that frees the embryo from its shell to allow implantation to occur. The more expanded the cyst has become, the more we favor the embryo for transfer.

In addition to looking at cyst expansion, the grade of the blastocyst is further determined by the integrity of the inner and outer cells. Embryos with more cells are better, and the best blastocysts are well expanded with distinct inner and outer cell populations. In poor quality blastocysts, there can be few cells in one or both populations, and/or the cavity can be small. And sometimes, even in embryos with beautiful outer cells, we cannot see any inner cells at all. These embryos are destined to fail since a full blastocyst with 32 cells is incapable of making inner cells if they do not already exist.

The embryos that are most difficult to assess are those where the cavity has just begun to open up, but has not expanded sufficiently to allow us to see inside. These early blastocysts are usually assigned lesser grades as we are unable to determine whether any inner cells are present. We often look at these embryos again several hours later to see if further expansion has revealed the presence of those critical inner cells. We would then re-grade the embryo, if appropriate.

All of this development, from fertilization to blastocyst expansion and hatching, normally follows a tight timeline that is independent of cell number. The embryo attempts to hatch from its shell approximately 5 or 6 days post fertilization, regardless of the number of cells it contains. If development is slow, and cell number is consequently low, the outer cells stretch to enclose the cyst and expansion continues. This is important, as the uterus waits only a few days for the embryo to implant. If the embryo takes too long to make the “right” number of cells for expansion and hatching, it may miss the implantation window. The practical result of this is that we still get high implantation rates even if only early blastocysts are available for transfer.

The above phenomenon is relevant to frozen embryo transfer cycles too, because many embryos lose one or more cells as a result of freezing and thawing. Such embryos still try to form blastocysts according to their original timeline, even though they may have less than the ideal number of cells. The consequences of arriving with plenty of cells but too late for the uterus are worse than having a chance to implant even with fewer cells. As a result, frozen-thawed embryos that have lost a cell or two are not assigned a lower grade since we still consider them to have high implantation potential.  

For many people, the dream of having a family also includes the dream of having children of both sex. Since most families today are much smaller than in generations past, the odds of having two or three or even four children of the same sex is fairly high.

Throughout human history, there always has been interest in methods to sway the chances of conceiving a child of a particular sex. Today, in the 21 st century, it is quite clear that many of these sometimes bizarre and sometimes simple home remedies have no basis in fact.

There are ways to significantly shift the odds of having a child of one sex or another. Sex is conferred on an embryo by whether an X-bearing sperm (for a girl) or a Y-bearing sperm (for a boy) enters the egg. Unfortunately, despite highly publicized claims, there are no proven effective “at home” methods of sperm separation. Nor does timing of intercourse relative to ovulation affect the 50:50 sex ratio. By natural methods, the ratio remains a flip of the coin.

The only commercially available method for sperm separation that appears to be effective is the sperm sorting process available through Microsort.net. This method involves using a fluorescent DNA dye that attaches to either X or Y chromosomes. The sperm then passes through a cell sorter that separates the sperm based on the fluorescence. This method is still under FDA investigation for safety and efficacy but does appear to do a reasonable job in separating sperm, especially if the desired sex is female.

Mirosort reports a 90% success rate with separating X-bearing sperm and a 73% success rate in separating Y-bearing sperm. There have been only a few hundred babies born thus far, but there does not appear to be any increase in birth defects. Because this process is still considered “experimental,” couples wishing to participate, will have to travel to either Fairfax, Virginia (Microsort headquarters) or an affiliated clinic in Southern California for fresh sperm insemination.

Unfortunately, after Microsort processing, the number of sperm available for insemination is severely decreased. Freezing and thawing of sperm, which would allow the sample to be shipped to another location, reduces these numbers even further. Because sperm counts are so low after sorting, it is usually necessary to do in vitro fertilization with sperm injection (IVF-ICSI) to significantly improve the fertilization in the IVF laboratory. PFC is a participating site in the FDA investigation for Microsort. We have used sperm specimens that had been previously Micro-sorted for IVF-ICSI.

Researchers at UC Irvine recently published a study describing the use of lasers to “trap” the heavier and slower moving X-bearing sperm to separate it from the lighter Y-bearing sperm. In the future, this process may provide an alternative to Microsort. However, it is not yet commercially available.

Beyond the Microsort technique, the only way to improve the odds of selecting one sex over another at close to 100% accuracy is to undergo Pre-Implantation Genetic Screening (PGS). PGS uses a DNA-binding technique to determine if there are a correct number of chromosomes in the embryo at the time of IVF. To complete this screening, embryos on Day 3 of culture (5-10 cells) undergo a biopsy to remove a single cell. The rest of the embryo remains in culture in the IVF laboratory. The removed cells are analyzed for the correct number of chromosomes. Currently, PFC with its cytogenetic partner, Genetics and IVF Institue screen embryos for 3-12 chromosomes. This screening is called “aneuploidy screening.” We allow our patients to know and select the sex of their normal embryos for transfer if they so wish.

Although IVF with PGS is the most effective method for sex selection, it is certainly the most expensive and there is no absolute guarantee that the transfer of the screened embryos will result in pregnancy. A PFC physician can best discuss the odds of success, based on the woman’s age and the couple’s history of childbirth.

Many couples undergoing PGS are doing so to screen for specific genetic defects or are specifically undergoing sex selection because of their risks of having a genetic disease that only affects males (X-linked diseases).

On the other hand, PGS for elective sex selection, either for “family balancing” or even for having a first child of a particular sex poses difficult ethical issues. Just because we have the ability to choose the sex of a child, should we? What will the couple do with normal embryos of the undesired sex? At PFC, we do not encourage PGS for elective sex selection. However, if a couple is undergoing IVF and wishes to undergo aneuploidy screening, we do allow them to select to transfer embryos by sex. We encourage all patients to consider donating excess embryos of the undesired sex for adoption by other couples.

Women or couples interested in this procedure should discuss it with their Reproductive Endocrinologist. At PFC, we also refer our PGS patients for a special genetic counseling session at California Pacific Medical Center in preparation for this process.

In vitro fertilization (IVF) is perhaps one of the most effective options available for the treatment of infertility. This procedure has been available in the developed world for approximately 30 years, and has been responsible for 1-4% of all conceptions. While IVF was originally developed for the treatment of female tubal factor, it has evolved to include treatment of male factor infertility via intra-cytoplasmic sperm injection (ICSI), as well as oocyte quality factor (Decreased Ovarian Reserve, or DOR). With the development of embryo biopsy techniques, IVF has also grown to incorporate pre-implantation genetic screening of embryos (PGD) to avoid genetic diseases in embryos and to screen for normal chromosomes. In the history of mankind, IVF will undoubtedly remain the greatest development for the treatment of human infertility for the foreseeable future.

Since the introduction of IVF, there has been a directly proportional increase in multiple gestation births. Traditionally IVF centers have measured success as the number of live births, irrespective of outcomes. This increase in multiple births is driven by the clinical incentives for live births, but some may also be driven by patient request. Two studies have shown that 20% of European and US infertile couples wanted a multiple birth^{(1, 2)}. Even after counseling regarding the risks of a multiple gestation, many patients still wanted to transfer 2 embryos. As IVF success rates have increased, and as the embryo freezing technologies have improved, a shift in the philosophy of IVF providers is occurring. Success rates are more likely to be measured as “live birth of a singleton (single baby) pregnancy”—in other words, “one healthy baby at a time”.

As the number of babies born after IVF has grown, there has been increased interest in looking at the pregnancy and birth outcomes in the successful IVF population. While potential complications for mother and babies are increased with any multiple gestation, there may also be an increased risk for complications even with IVF singleton babies. However, it may not be the IVF treatment itself that results in this increased risk for complications. The questions that reproductive endocrinologists and high-risk pregnancy specialists are trying to answer are primarily: 1) Is there a higher risk for a baby of any adverse birth outcome if that baby is conceived in an IVF laboratory? and 2) Is there something inherent about a past diagnosis of infertility which places even a singleton gestation at greater risk of pregnancy and birth complications?

IVF Singletons:

A number of large studies have addressed the question of increased risk to IVF babies ^(3-7). They echo a similar theme concerning birth outcomes, most importantly preterm birth <37 weeks, and low birth weight. One study compares the differences in degree of risk of poor outcomes with IVF babies vs. naturally-conceived babies. There appears to be a 93% increased risk for IVF singletons as compared to naturally conceived singletons, and a 57% increased risk for IVF twins versus naturally conceived twins⁽⁶⁾. Certainly the overall chance of a preterm delivery is much smaller for singletons than twins, and a twin pregnancy carries much greater risks overall.

A review of the US birth registry indicates that the proportion of IVF singleton babies born at full term with low-birth-weight is decreasing, but the proportion of IVF singleton babies born prior to full term with low-birth-weight is stable. In either case, the incidence of low-birth-weight is higher in babies born after IVF when compared with the general population. While outcomes of low-birth-weight babies may be getting better, there are still elevated risks for singleton low-birth-weight babies conceived via IVF.

For most of these studies looking at risks for IVF babies, factors known to influence pregnancy and birth outcomes are taken into consideration in the analysis. These important factors include maternal age and prior birth history. However, other factors may also be important but are not as well accounted for: factors such as previous poor obstetrical outcome, smoking status, socio-economic status, performance of fetal reduction procedure (especially for the analysis of the singleton data), types of ovarian stimulation protocols, media used in the IVF laboratory, and/or use of laboratory techniques (ICSI, etc.).

Infertility per se may itself be a risk factor for poorer pregnancy and birth outcomes. In an attempt to answer this important question, IVF outcomes have been compared with either non-IVF fertility treatments such as ovulation induction (OI) or to spontaneous conception outcomes. Numerous studies ^(8-15) have evaluated this question, and shown a higher risk of preterm birth for both IVF and OI babies as compared to spontaneously conceived singleton pregnancies. When evaluating outcomes for sub-fertile women (infertility for greater than 1 year) who spontaneously conceive, again we see a greater risk of preterm deliveries, obstetrical complications and adverse birth outcomes ^(16-18). These studies strongly suggest that there is an inherent characteristic of infertile patients which place them at greater risk of poorer pregnancy and birth outcomes. Whether this is due to uterine or embryo issues is not yet known.

IVF Twins:

Many studies have compared the outcomes for twins conceived via IVF versus spontaneous conception. These outcomes were summarized and reviewed in a meta-analysis of birth outcomes of IVF twins in studies up to 2003 ⁽¹⁹⁾. The specific findings showed an increase in the chances of a preterm birth (57% increase), admission to the neo-natal intensive care unit (two-fold increase), and Cesarean section delivery (33% increase). No other parameters were significantly different from spontaneously-conceived twins.

These differences between twin gestations conceived via IVF versus spontaneously-conceived twins were similar for cycles of twin gestation conceived via ovulation induction (OI). The rate of prematurity seemed to be higher for the IVF than OI group ⁽²⁰⁾.

In conclusion, when comparing singleton or twin gestations conceived via IVF or spontaneously, the degree of difference in the overall risk is greater for the singleton-baby births than twins. This is especially true with regards to preterm delivery which is increased two-fold in IVF singletons and by 40% (adjusted for age) in twins. While most studies have made adjustment for factors which can affect birth outcomes, such as maternal age, some other potential factors are difficult to measure, such as history of infertility or direct effects of IVF technology itself. It appears as though infertility prior to conception may play a larger role in IVF outcomes, for both singleton and twin gestations.  

1. Thurin A et al. Elective single-embryo transfer versus double-embryo transfer in in vitro fertilization. N Engl J Med 2004; 351:2392-2402.
2. Ryan GL et al. The desire of infertile patients for multiple births. Fertil Steril 2004; 81; 500-504.
3. Jackson RA et al. Perinatal outcomes in singletons following in vitro fertilization: a meta-analysis. Obstet Gynecol 2004; 103; 551-563.
4. Helmerhorst FM et al. Perinatal outcomes of singletons and twins after assisted conceptions; a systematic review of controlled studies. BMJ 2004; 328; 261.
5. McGovern PG et al. Increased risk of preterm birth in singleton pregnancies resulting from in vitro fertilization-embryo transfer or gamete intrafallopian transfer: a meta-analysis. Fertil Steril 2004; 82; 1514-1520.
6. McDonald SD et al. Perinatal outcomes of singleton pregnancies achieved by in vitro fertilization: a systematic review and meta-analysis. J Ostet Gynaecol Can 2005; 27; 449-459.
7. Bower C et al. Assisted reproductive technologies and birth outcomes: overview of recent systematic reviews. Reprod Fertil Dev 2005; 17; 329-333.
8. French National IVF Registry. Analysis of 1986 to 1990 data. Fertil Steril 1993; 59; 587-95.
9. Frydman R et al. An obstetric assessment of the first 100 births from the in vitro program of Clamart, France. Am J Obstet Gynecol 1986; 154; 550.
10. McFaul P et al. An audit of obstetric outcome of 148 consecutive pregnancies from assisted conception: implication for neonatal services. Br J Obstet Gynecol 1993; 100; 820-5.
11. Tan S et al. Obstetric outcome of In vitro fertilization pregnancies compared with normally conceived pregnancies. Am J Obstet Gynecol 1992; 167; 778-84.
12. Wang JX et al. The obstetric outcome of singleton pregnancies following IVF/GIFT. Hum Reprod 1994; 9; 141-6.
13. Tanbo T et al. Obstetric outcome in singleton pregnancies after assisted reproduction. Obstet Gyncol 1995; 86; 188-92.
14. Rufat P et al. Task force report on the outcome of pregnancies and children conceived by in vitro fertilization (France 1987-1989). Fertil Steril 1994; 154; 550-5.
15. Friedler S et al. Births in Israel resulting from in vitro fertilization/embryo transfer. 1982-1989: National registry of the Israeli association for fertility research. Hum Reprod 1992; 7; 1159-63.
16. Basso O et al. Subfecundity and neonatal mortality: longitudinal study within the Danish national birth cohort. BMJ 2005; 330; 393-394.
17. Basso O et al. Infertility and preterm delivery, birthweight, and Caesarean section: a study within the Danish National Birth Cohort. Hum Reprod 2003; 18; 2478-2484.
18. Pandian Z et al. A review of unexplained infertility and obstetric outcome: a 10 year review. Hum Reprod 2001; 16; 2593-2597.
19. McDonald S et al. Perinatal outcomes of in vitro fertilization twins: a systematic review and meta-analysis. AM J Obstet Gynecol 2005; 193; 141-152.
20. Adler-Levy Y et al. Obstetric outcome of twin pregnancies conceived by in vitro fertilization and ovulation induction compared with those conceived spontaneously. Europ J Obstet Gynecol and Reprod Biol 2007; 133; 173-178.

Question: I am 35 years old and single, but am still hoping to find my life partner. I am getting a little concerned as my gynecologist has asked me about my plans for having children. She mentioned that I might want to consider freezing my eggs for future pregnancies. Is this something I should do?

Answer: Vitrification is a very new process for preserving unfertilized eggs. As noted in this month’s lead article, PFC has successfully been vitrifying oocytes from proven egg donors. Our first birth from this process occurred in October. Three additional pregnancies from this trial are ongoing. PFC undertook this vitrification trial in order to develop expertise with the technology of oocyte vitrification. For this reason, our study population was confined to donor eggs from healthy donors in their mid-twenties who had successfully completed conventional egg donation.

Why do we want to freeze eggs? For the many single young women diagnosed with cancer and facing fertility-threatening chemotherapy, egg vitrification will provide a fertility preservation option. This group of women has a compelling reason to consider undertaking the procedures and costs involved with in vitro fertilization. The potential threat to their ability to have their own biological children in the future may justify the unknowns that are involved with preserving their eggs in this manner. These unknowns include whether their eggs will survive the vitrification process and whether egg vitrification will ultimately prove to be as safe as conventional in vitro fertilization and embryo cryopreservation. The answers to these questions may not be answered until the patient’s eggs are warmed, fertilized and implanted, which may be years later.

We recognize that a much broader spectrum of the population will look upon oocyte vitrification as a way for women to preserve their fertility. Single women, such as you, who have not yet met their life partner, may be particularly interested in this option. In addition, it may also become an option for women in their 30’s who wish or need to delay their childbearing.

Many questions remain unanswered. Will eggs from women in their 30’s do as well as eggs from proven egg donors in their 20’s? Logic suggests older eggs will not do as well, but will the differences be significant? How many eggs would a woman need to preserve in order to have a reasonable chance for one or two children in the future? How many IVF cycles will that take? Is it safe to rely on these preserved eggs? Would having preserved eggs change a woman’s approach to reproductive planning in her life?

These are not trivial issues. They are important, life-changing concerns. For these reasons, we are not encouraging single women to prematurely jump on the egg vitrification bandwagon. Stay tuned. This area is changing rapidly.

Dr. Carolyn Givens