Every year, several Pacific Fertility Center professionals participate in ASRM’s national meeting. They evaluate the research and share their findings with PFC and Fertility Flash.

Among those attending the conference from PFC were Dr. Philip Chenette and Dr. Isabelle Ryan and Peggy Orlin, MFT. Their reviews cover the following topics: Update #1: Ovarian Stimulation Techniques, Update #2: PGD and Aneuploidy Screening Techniques, Update #3: Egg Freezing, Update #4: Acupuncture, and Update #5: Men and ART.

Update #4: Acupuncture

The published study of German Paulus ⁽¹⁾ reported improved pregnancy rates with a one-time acupuncture treatment pre-and-post embryo transfer. This sparked great interest for providers of fertility treatment, in both the conventional and Chinese medicine (TMC) communities (see Fertility Flash March, 2004). A few years later, a study from Denmark ⁽²⁾ reported improved pregnancy rates in patients receiving pre-and-post transfer acupuncture, but no improvement if there were two post-transfer treatments. In both of these studies, there were no sham acupuncture (i.e. simulated but not real acupuncture) treatment controls.

Smith ⁽³⁾ and colleagues in Australia did compare acupuncture versus sham acupuncture (but did not include a no-treatment control group), using 3 treatment sessions: ovarian stimulation day 9, pre and post embryo transfer. There was no difference found in these different study groups. Interestingly, subjects in the sham control group were more likely to report relaxation as a side effect of acupuncture. Some studies indicate that sham acupuncture evokes acupressure, and in this way, may trigger physiological responses.

In all the above studies, the acupuncture treatments were performed within the IVF centers (patients did not have to travel off-site). In general, there were no more than 100 patients per treatment group.

At ASRM, Dr. Craig and colleagues reported an acupuncture study conducted in Seattle, using 3 IVF clinics. The acupuncture sessions were performed off-site by 2 acupuncturists. The patients were randomized to pre- and post-transfer acupuncture vs. no treatment. The physicians were not aware if the subjects were or were not receiving treatment. A total of 97 patients were studied (about 50 patients per treatment group). Clinical pregnancy and live birth rates were as follows: 54% and 39% for the acupuncture group, and 78% and 65% for the control group. These results were statistically significant. Of all the acupuncture studies thus far published, this is the first study to suggest a possible detriment to the use of acupuncture in IVF treatment.

One of the important differences for this study versus other randomized controlled trials is that all the patients had to go to an off-site acupuncture center for their treatment. This may be an important factor when a patient has to travel to the acupuncture clinic immediately before and immediately after an embryo transfer. Perhaps this factor would increase stress levels. Another important difference for these Seattle IVF centers was that baseline pregnancy rates are much higher than the previously-studied non-US centers. The higher the baseline pregnancy rate, the more difficult it is to show a difference in treatment results— so a statistically significant result would be more credible.

Ideally, a multi-center randomized-controlled-trial should be performed where the following comparisons can be evaluated: acupuncture pre-and-post transfer, no-acupuncture control group, sham-acupuncture control group, and these 3 groups can be compared at both on-site and off-site acupuncture centers. Each study group would require at least 100 patients, so this would require about 1000 patients total.

As we have a chance to collaborate with TCM providers, and as patients are willing to participate in these large multi-center randomized clinical trials, we will gain a better understanding about whether a mix of allopathic and TCM medicine improves overall care, and which combination of treatments may be the most beneficial for our mutual patients.

Isabelle Ryan, MD

References:

(1) Influence of acupuncture on the pregnancy rate in patients who undergo assisted reproduction therapy. Fertil Steril. 2002, Apr; 77(4):721-4.

(2) Acupuncture on the day of embryo transfer significantly improves the reproductive outcome in infertile women: a prospective, randomized trial. Fertil Steril. 2006 May; 85(5):1341-6.

(3) Influence of acupuncture stimulation on pregnancy rates for women undergoing embryo transfer. Fertil Steril. 2006 May; 85(5):1352-8.

Every year, several Pacific Fertility Center professionals participate in ASRM’s national meeting. They evaluate the research and share their findings with PFC and Fertility Flash.

Among those attending the conference from PFC were Dr. Philip Chenette and Dr. Isabelle Ryan and Peggy Orlin, MFT. Their reviews cover the following topics: Update #1: Ovarian Stimulation Techniques, Update #2: PGD and Aneuploidy Screening Techniques, Update #3: Egg Freezing, Update #4: Acupuncture, and Update #5: Men and ART.

ASRM Update #3: Egg Freezing

Oocyte cryopreservation is the storage of the female gamete, the egg, prior to fertilization. Preservation of fertility for single women that must undergo cancer therapy or surgery, or that must delay or choose to delay childbearing, and donated oocyte banking are all applications of oocyte cryopreservation. The need for this technology is clear, but reports of success with oocyte cryopreservation have been limited.

Highly successful oocyte cryopreservation is now attainable. New studies are showing pregnancy rates with oocyte cryopreservation that are equal to traditional IVF techniques.

The key to this technology is oocyte vitrification – an ultrarapid cryopreservation technique. Researchers from Atlanta described their experience with vitrification. Out of 11 patients with transfers, nine conceived, with an implantation rate of 65%.

Pregnancies after oocyte cryopreservation have developed normally. An Italian study of 105 children born after oocyte cryopreservation showed no problems. A Chicago study of the genetics of oocytes, embryos, and children born after oocyte cryopreservation was reassuring. No increase rates of aneuploidy or malformations were reported, and normal development was found in post-natal follow-up.

These results are similar to those we have previously reported from our own research at Pacific Fertility Center (see December 2007 Fertility Flash). Oocytes are now cryopreserved with high success rates. Oocyte cryopreservation technology has matured, and we look forward to providing these techniques for our patients.

Philip Chenette, MD

Every year, several Pacific Fertility Center professionals participate in ASRM’s national meeting. They evaluate the research and share their findings with PFC and Fertility Flash.

Among those attending the conference from PFC were Dr. Philip Chenette and Dr. Isabelle Ryan and Peggy Orlin, MFT. Their reviews cover the following topics: Update #1: Ovarian Stimulation Techniques, Update #2: PGD and Aneuploidy Screening Techniques, Update #3: Egg Freezing, Update #4: Acupuncture, and Update #5: Men and ART.

Update #2: PGD and Aneuploidy Screening Techniques

Preimplantation genetic diagnosis (PGD) has been one of the hallmark technologies of modern reproductive medicine. The ability to look inside a cell, beyond its visual appearance to the actual genes controlling the cell, has provided insight into the workings of the embryo and a valuable clinical tool to improve fertility care.

The most common use of PGD is to count chromosomes using FISH probes. Using labels that glow under ultraviolet light, a limited number of chromosomes can be identified and counted. Missing or duplicated chromosomes are indicators of abnormalities in the embryo, a condition known as “aneuploidy.” FISH has a significant error rate, and while clinically useful, results must be interpreted with caution.

A new technique discussed at the ASRM meeting is SNP analysis. SNPs are common tags in DNA that can be measured by automated systems. Microarrays of thousands of SNPs have been prepared that provide a clear picture of the chromosome structure of a cell. Microarray-based aneuploidy screening has excellent reliability and accuracy, and holds enormous promise for identifying genetically normal embryos. This study represents the first validated method of analyzing the entire set of chromosomes in a single cell. Stay tuned for more on this exciting technology.

Array CGH uses thousands of very small DNA probes along with computer software to describe the structure of DNA in a single cell. A very sensitive test, it is fast enough to be used during an IVF treatment cycle, and far more accurate than conventional fluorescent probe (FISH) analysis. Array CGH may lead to improved IVF outcomes as embryos containing an error in any chromosome can be detected, which would allow better selection of healthy embryos.

PGD has proven useful for the treatment of recurrent miscarriage. In an analysis of 279 patients with recurrent miscarriage (women who had previously experienced 3-5 miscarriages), researchers in New Jersey found an improved miscarriage rate of 19.5% after PGD versus their 40.9% expected rate.

Philip Chenette, MD

Every year, several Pacific Fertility Center professionals participate in ASRM’s national meeting. They evaluate the research and share their findings with PFC and Fertility Flash.

Among those attending the conference from PFC were Dr. Philip Chenette and Dr. Isabelle Ryan and Peggy Orlin, MFT. Their reviews cover the following topics: Update #1: Ovarian Stimulation Techniques, Update #2: PGD and Aneuploidy Screening Techniques, Update #3: Egg Freezing, Update #4: Acupuncture, and Update #5: Men and ART.

Update #1: Ovarian Stimulation Techniques: Changes in ovarian stimulation techniques evolve as a better understanding of the medications and their effects on eggs and ovaries develops.

Letrozole (Femara) is increasingly being used as a mild stimulation for ovarian follicle growth and as an additional medication with gonadotropins (e.g. Follistim). In a study on the use of letrozole in preparation for IVF in breast cancer patients, a group from New York showed that breast cancer recurrence or the incidence of invasive carcinoma in the opposite breast does not appear to be increased after stimulation using letrozole and FSH for fertility preservation.

For patients with PCOS, researchers from France compared stimulation with a GnRH agonist, similar to Lupron, with oral contraceptives plus agonist. In these preliminary results, dual suppression does not provide any obvious effect in harmonizing the group of developing follicles nor in improving the quality of oocytes and embryos. This study is still ongoing in order to test these results in a larger population.

In patients that produce an excessive number of follicles in response to stimulation, ovarian hyperstimulation syndrome (OHSS) is possible. To prevent this, the fertility drugs are sometimes stopped mid-stimulation; the follicles are “coasted” – they grow without stimulation, with a lower risk of OHSS. An alternative to “coasting” is the use of Ganirelix, a GnRH antagonist, in a “salvage protocol.” Probability of live birth with the Ganirelix salvage protocol was similar to controls. High-grade embryos were more common with this regimen, in contrast to “coasting”. The miscarriage rate was slightly higher, but not statistically significant. These results suggest that the Ganirelix salvage regimen is a superior alternative to “coasting” in women at risk for OHSS.

A group in Montpelier, France is interested in gene expression in the follicle after use of fertility drugs. Using gene chips they measured gene expression in patients exposed to urinary FSH products and recombinant FSH. Significant differences were found meaning that different genes are being expressed in follicles of women receiving pure FSH (Gonal-f or Follistim) as compared to genes being expressed in follicles of women receiving urinary FSH (Repronex or Menopur)– the meaning of these changes will have to await further study.

On the other hand, a long debate about the effectiveness of urinary and recombinant FSH products is a bit closer to resolution. A meta-analysis from a group in Egypt examined pregnancy outcomes and risks in a group of previously published studies. No significant differences were found. Their conclusion was that urinary gonadotropin (hMG) is as effective as recombinant gonadotropin with regards to clinical outcomes and patient safety.

Philip Chenette, MD

In late October of this year, our first patient who underwent embryo transfer with embryos created from vitrified and warmed donor oocytes has successfully delivered. The baby was born at term and appears to be perfectly healthy.

Three other pregnancies are ongoing and are expected to deliver in 2008. We congratulate our new parents and the parents-to-be who have participated in this ground breaking program.

PFC has ended enrollment of patients into this program, but expects to continue research efforts with respect to oocyte vitrification.

While it has been possible to preserve sperm for many years (the famed Dutch microscopist Anton von Leeuwenhoek allegedly cooled and then recovered sperm using snow and ice in the 17th century), reliable methods for oocyte preservation have been elusive.

We previously discussed some of the problems with oocyte freezing (see Fertility Flash, January 2005, Volume 3, Issue 1), and now report our success in overcoming some of the obstacles.

Traditionally, preservation of sperm and embryos has been achieved with the use of a technique called slow freezing. This process incubates the sperm or embryos in low concentrations of cryoprotectants (antifreeze) to draw water out of the cells. After this incubation, they are cooled very slowly to sub zero temperatures. Typically this slow freezing technology just works for cells that exist individually (such as sperm), or together in small numbers (embryos), as the water must be extracted from every cell. Tissues, which are made up of many hundreds of thousands of cells, cannot be dehydrated successfully and therefore cannot be frozen intact. Cells in the tissue can burst when the water remaining in the cells expands as it turns to ice. For example, it is not possible to freeze a whole ovary, but some success has been achieved with ovaries that were cut into tiny pieces.

Frustrated by the lack of progress with slow freezing, scientists have more recently moved towards a technology called vitrification for oocyte preservation. Vitrification, which was described in detail in September’s Fertility Flash (Volume 5, Issue 8 ) works by using higher concentrations of cryoprotectants and much faster cooling rates. Cells are typically cooled in tiny straws (see article heading). This process allows us to achieve cooling rates of several thousand degrees per minute.

When vitrification straws and cryoprotectants were first approved by the FDA for human embryos, PFC began the process of adapting the technology to oocytes. Our embryologists attended training courses and became proficient with the technology by practicing on mouse and hamster oocytes and embryos. Even though we have been handling oocytes and embryos for many years, this technology provided many new challenges, mainly due to the tiny size of the straws and the speed at which the cells had to be cooled. Once we became proficient with the procedure, we began to freeze high quality oocytes from donors who had proven fertility. In this way, we knew that if the procedure did not work, it would be the vitrification technology and not the oocytes that were to blame. In addition, we satisfied ourselves that the technology was safe by looking at the exhaustive work by Dr. Gary Smith at the University of Michigan, which showed that vitrified/warmed oocytes were both physically and genetically normal and that the resulting pregnancies and babies were healthy.

We recruited five oocyte donors and vitrified all of their oocytes immediately after their oocyte retrieval procedures. We then offered the oocytes to individuals who were on our waiting list to accept donated embryos. Typically, these individuals were unable to get pregnant with their own oocytes or financially unable to proceed to an egg donor cycle. The availability of the vitrified oocytes was a great alternative to accepting donated embryos as it allowed couples to choose their own sperm source. Furthermore, the immediate availability of vitrified oocytes was an attractive alternative to what may be a very long wait for donated embryos.

Pacific Fertility Center had immediate success with the first recipient. We had vitrified 16 oocytes from the first donor, and for the first recipient we warmed only 7 of these. Four hours later we injected a single sperm into each of the 6 oocytes that appeared alive and healthy (1 oocyte had not come through the process successfully). The next morning, 3 of the oocytes fertilized normally. After 2 more days, we had 3 nice embryos for transfer. The positive pregnancy test 11 days later, and a singleton pregnancy confirmed by ultrasound at 7 weeks were great rewards for our efforts and thrilling news for the recipient. Our second recipient used a different donor and although her pregnancy started out well, she miscarried in the first trimester. Our disappointment over this loss was compounded when we discovered the oocytes from 2 of the donors did not survive well when warmed. In these particular donors, we recovered high numbers of oocytes (each had close to 40) and for unknown reasons their oocytes were overly sensitive to vitrification. The next three donor cycles proceeded well and resulted in pregnancies. These 3 pregnancies are all ongoing at the time of writing. We will update readers with their outcomes at a future date.

Although we were warming relatively small numbers of oocytes (typically 6 or 7), we began to have more embryos than could be safely transferred to recipients. Our first pregnancy had been achieved after transferring 3 embryos. It is more typical, however, to transfer only 1 or 2 embryos when donor oocytes are used. Even when using only 2 embryos, multiple pregnancy rates were unacceptably high. Understandably, few patients are willing to risk a decreased chance of conceiving by transferring only a single embryo. In order to avoid high multiple pregnancy rates in a typical IVF cycle, embryos are usually cultured for 5 days to determine which embryos in a cohort have the best chance of establishing a pregnancy. However, if a patient has only a few embryos, the benefits of extended culture are less, and the transfer is typically done after only 3 days growth. With our recipients of the vitrified oocytes, we began by doing 3-day transfers. Once high success rates were evident, we elected to implement day-5 transfers, in an effort to decrease high order multiples. The last 2 pregnancies both resulted from day-5 transfers of 2 embryos each, and they are both twin gestations.

In summary, we have had 7 out of 10 embryos implant after transfer (excluding the 2 failed donors with the high oocyte numbers). This implantation rate (70%) is comparable to the implantation rates that our patients have when using fresh embryos from donor oocytes.

We are moving forward cautiously with our oocyte vitrification program and hope to use the remaining oocytes soon. While these results are encouraging and have brought great joy to a small number of our patients, there are more issues to resolve before we declare complete success. The 70% success rate was obtained with the use of the highest quality oocytes from young donors who were known to be fertile and healthy. We have already seen that some oocytes are less tolerant of the procedure, as evidenced by the results from the 2 donors with high oocyte numbers. We also fully anticipate that the results for older women using their own oocytes will be worse, as they are for these same patients using a fresh IVF cycle. In fact, at this time, we do not have any idea if the oocytes from women in their 30’s will be able to tolerate vitrification.

Going forward, we will offer oocyte vitrification unconditionally to women with cancer who are likely to be left sterile by their treatment. For these women, and for others who elect to vitrify oocytes for social reasons, we will exercise great caution in our estimates of future pregnancy potential with the warmed oocytes. Until we have more data with oocytes from a variety of women, we will have no way of telling if there is any hope from anything other than donor oocytes. That data will accumulate more slowly because women who elect to preserve oocytes are not likely to be using them for some time. For now, until there is more data, we continue to believe that embryo freezing has the greatest potential for those wishing to preserve future fertility. However, for those who are single and in their late 30’s, we will be reluctant to recommend oocyte vitrification as a reliable fertility preservation method. Hopefully, they will find Mr. Right before we have objective data.

Joe Conaghan, PhD, HCLD

Many IVF programs routinely schedule frozen embryo transfers (FET) to occur on specific days by putting their patients on estrogen and progesterone to prepare the uterine lining for implantation. This allows for a flexible schedule for the clinic and the patient, i.e. it allows the clinics to group FETs together and avoid weekend transfer procedures. However, the patient must remain on both estrogen and progesterone to support the pregnancy for up to 12 weeks.

More and more, clinics are starting to schedule FETs in natural cycles, timed to natural ovulation with minimal medications. This does mean that a transfer can occur any day of the week. Due to tradition and convenience, some clinics remain hesitant to switch to natural cycle FETs. Part of the problem is that there have been very few studies showing what the success rates were in natural vs. programmed FET cycles. The few studies that have been published have reported on a fairly limited number of cycles.

Pacific Fertility Center has always been a proponent of natural cycle FETs. Because we do about 400 FETs each year, we have been able to gather a large number of cycles to evaluate. Most of our patients we evaluated for this study were in natural cycles but some patients had to do programmed cycles because they did not ovulate regularly or because they had to travel some distance to come to PFC for their FET and needed to have the more precise scheduling that a programmed cycle affords.

In our study, we looked at 1,378 frozen embryo transfers done between 2000-2005. Of these, 934 were done in patients using embryos from their own eggs and 444 were done in patients using embryos from donor eggs. The bottom line is that there were no differences in delivered pregnancy rates within both groups of patients (own eggs and donor eggs) between those patients having a transfer timed to natural ovulation or those patients with estrogen-progesterone uterine preparation.

Because we feel that a natural cycle is less costly, requires no blood tests and (usually) fewer ultrasounds and injections, patients find this a desirable alternative to the more common, programmed FET. In addition to these patient-friendly reasons for choosing natural cycle FETs, we now feel PFC has solid data to justify this approach.

Preliminary results of this study were presented at an oral presentation at the Pacific Coast Reproductive Society meeting in Palm Springs this past April (see sidebar).

This study has just been submitted to Fertility and Sterility, the major reproductive endocrinology journal of the American Society for Reproductive Medicine. We expect full publication after the peer review process is completed.

Carolyn Givens, MD

“Outcomes of Natural Cycles vs. Programmed Cycles for 1378 Frozen Embryo Transfers” Carolyn R. Givens, M.D.a, Leslie C. Markun,b Isabelle P. Ryan, M.D.,a Philip E. Chenette, M.D.,a Carl M. Herbert, M.D.,a and Eldon D. Schriock, M.D.a Submitted July 2007 to Fertility and Sterility.

Will my fibroids prevent me from getting pregnant?
A recent PFC study can help answer that question.

Every complete infertility evaluation includes a thorough evaluation of the uterus, where embryo implantation is expected to occur. At Pacific Fertility Center we typically start with a vaginal ultrasound to evaluate for the presence of fibroids (benign growths of the muscle layer), polyps (benign growths of the lining of the uterus), measure the lining thickness of the uterus and observe the uterine lining pattern. If uterine abnormalities are noted, a saline hysterogram (saline ultrasound) or hysteroscopy (visualizing the uterine cavity with a thin telescope) may be recommended.

Fibroids (uterine leiomyomas) are present in 20-40% of reproductive age women. The location of the fibroid(s), relative to the lining of the uterus, is important in determining if it will impact chances of pregnancy. Fibroids which distort the uterine lining and cavity are known to decrease pregnancy rates for patients undergoing fertility treatment. Only about 5% of fibroids directly distort the uterine cavity. The influence of fibroids which do not distort the uterine cavity has remained controversial.

To best determine if non-distorting fibroids also may have an impact on fertility treatment, requires the analysis of a large number of fertility cycles following patients who have non-distorting fibroids, and patients who have no fibroids. Most studies have small numbers of observed cycles, making statistical analysis difficult. One strategy for circumventing this problem, and gathering enough treatment cycles to draw meaningful statistics, is to have large IVF centers collaborate and “pool” data. This type of study is called a multi-center study.

Pacific Fertility Center (PFC) and the University of California San Francisco (UCSF) IVF centers collaborated in just such a study; gathering data on past treatment cycles of egg donor recipients with non-cavity distorting fibroids and without fibroids. Analysis of pregnancy (PR) and implantation (IR) rates were assessed. A total of 369 cycles were analyzed, of which 94 were for patients with fibroids. All recipients underwent their first oocyte donor cycle, and a fresh embryo transfer. Any uterine abnormalities other than non-distorting fibroids were excluded from the study analysis. The primary outcome measure was a clinical pregnancy. Implantation rate was a secondary outcome of the study. We also analyzed to see if the fibroid location: subserosal (growing towards the outside of the uterus) versus intramural (confined to the muscle layer) or if the fibroid diameter impacts PR and IR, as well as miscarriage and ectopic rates.

The following results were revealed.

The clinical pregnancy rate (PR) was not different between the two groups (no fibroids vs fibroids) (54% vs 47%). The implantation rate (IR) was also similar between the groups (38% vs 36%). Miscarriage rates were similar (9% vs 15%). Ectopic pregnancy (which is typically a rare outcome) showed results of 1% vs 4%, which also was not statistically significant. Location and diameter of fibroids did not show a significant impact on PR.

When screening ultrasounds identify fibroids, “treatment” of these lesions is tempting to both providers and patients, especially in cases of unexplained infertility. Our data suggest that there is inadequate evidence to conclude that fibroids which do not distort the uterine cavity have a significant effect on clinical pregnancy rates (PR) in patients undergoing IVF. Thus, there is inadequate evidence to support myomectomy for patients with non-distorting fibroids. Myomectomy may unnecessarily place the patient at risk of delayed treatment, as well as possible surgical morbidity. It is also unknown whether surgery itself may have a negative impact on pregnancy outcome- though our data did not show a lower PR in patients who had past myomectomies.

Future collaborative studies will investigate whether the distance of the closest fibroid to the uterine lining may impact PR and IR. Fibroid volume will also be investigated. These studies are currently in the design phase.

Isabelle Ryan, MD

“The effects of fibroids without cavity involvement on ART outcomes independent of ovarian age”, PC Klasky, DE Lane, IP Ryan, VY Fujimoto, Hum Reprod Advance Access, published September 22, 2006.

The American Society for Reproductive Medicine’s (ASRM) annual meeting was held in New Orleans. It is the largest meeting for reproductive medicine specialists and scientists in the world. From our practice, Dr.s Givens, Schriock and Conaghan attended, as well as embryologists Jean Popwell, PhD and Jennifer Andres. Also, PFC nurse Allison Chamberlaine and PFC’s Marriage and Family Therapist Peggy Orlin attended. In addition, the genetics counselor with whom we work closely, Lauri Black from California Pacific Medical Center, was an attendee and active participant.

PFC’s embryologists attending ASRM’s research poster session Jean Popwell, PhD (left) and Jennifer Andres (right).

Single-Embryo Transfer: Minimizing Risks & Maximizing Outcomes
Dr. Givens attended a post-graduate course entitled “Moving Toward Single-Embryo Transfer: Minimizing Risks and Maximizing Outcomes.” This two-day course dealt with a pressing issue in assisted reproduction: the high incidence of multiple gestations. With the ever-increasing success of in vitro fertilization and the significant improvement in embryo implantation rates, the incidence of twin and higher-order pregnancies has risen dramatically in this country. Many countries now regulate the maximum number of embryos that can be transferred into the uterus at one time. The course topics included a summary of optimal medication protocols, several lectures on pre-cycle evaluation and testing and embryo transfer techniques.

Oocyte Freezing, PGS & Blastocyst Embryo Transfers
On the laboratory side, there were several talks on evaluation of eggs and embryo selection techniques, embryo freezing technology, including a debate about the usefulness of pre-implantation genetic screening (chromosome analysis of embryos) embryo selection. The combination was a fascinating mixture of new ideas, refinements in current technology, as well as a welcome opportunity to network and discuss with others the latest developments in reproductive science. Topping the list of presentations in New Orleans were those concerning the continuing refinements in oocyte freezing technologies, the more selective use of preimplantation genetic testing and the ongoing scrutiny of blastocyst stage embryo transfers.

Slow-freeze vs. Vitrification
The traditional slow-freeze technology used so successfully with embryos for many years, has essentially stalled with oocyte freezing. It appears the slow-freeze technology has finally met its successor: a process called vitrification. Slow freezing has had very limited success with oocytes due to their large size, high water content and their extreme sensitivity to cryoprotective chemicals and to changes in temperature and pH.

Vitrification, a technology that cools cells so rapidly that ice does not form, has been such a success for oocyte freezing that many labs are now abandoning slow freezing altogether. Here at PFC, we have been developing protocols for oocyte vitrification throughout 2006 and are actively working on blastocyst vitrification. It was reaffirming to see that this technology has gained wide acceptance, and is showing excellent results.

Preimplantation Genetic Screening (PGS)
While vitrification is on the rise, it was interesting to see that another technology, Preimplantation Genetic Screening (PGS), was lacking in new improvements or viable alternatives. Embryos have been screened for extra or missing chromosomes for over 15 years now, but the technology has not advanced significantly over that time. It is still possible to count only 12 chromosomes in an embryo. Although the error rate per chromosome is very low, the accumulated error rate becomes significant as we count more chromosomes. PGS was “under the microscope” in several presentations in New Orleans and it appears PFC’s limited use of genetic screening is well justified. Specifically, PGS does not improve embryo selection and pregnancy rates in younger patients. Its use is limited in older patients because there are often too few embryos available to justify testing. The patients who benefit most from PGS are the younger patients who experience recurrent miscarriages. However, unless there is evidence that previous pregnancies were genetically abnormal, PGS may provide limited benefit to this group.

Blastocyst stage embryo transfers
While younger patients (those under 35) don’t benefit from PGS, they are the patient population most likely to benefit from blastocyst transfers. Culturing embryos for 5 days to the blastocyst stage, instead of the more traditional day 3 embryo transfer, is one of the main ways in which the laboratory staff can help in selecting the “best” embryo for single embryo transfer (SET) patients. Blastocyst culture techniques are well refined now and support the commitment within the community to transfer fewer embryos at one time. Furthermore, the promise of vitrification can reassure patients that their remaining embryos can be stored indefinitely when preserved at the blastocyst stage. Several presentations showed that blastocysts which were vitrified early, before their cavity (or cyst) had expanded too much, benefited most from the technology. In more advanced blastocysts, artificial reduction of the cavity gave superior results. It may not be long before vitrification is the procedure of choice for preserving all blastocysts.

2006 ASRM guidelines for numbers of embryos to transfer
The new 2006 ASRM guidelines for numbers of embryos to transfer were presented. See Tables 1 and 2 below.

The topic of whether or not federal or state legislation should regulate the maximum number of embryos to transfer was also discussed. Many people in the general public support such legislation but those of us in the field (and most patients) are opposed to the government regulating medical practice and arbitrarily setting limits on embryo transfer. In order to forestall such legislation, it is obvious that we must decrease the number of twin gestations (the number of triplet and higher-order gestations has already dramatically decreased in the last 5-7 years). At Pacific Fertility Center we have instituted a new emphasis on single embryo transfers and expect to significantly reduce the risk of multiples and achieve our goal of “optimal” pregnancy outcomes. (See From Us to You in this issue for a discussion of our 2006 statistics and please see Conception Health in this issue for a discussion of why it is important to try to achieve single baby conceptions.

– Carolyn Givens, MD and Joe Conaghan, PhD

PFC continues to be at the forefront of pioneering research in assisted reproductive technology and was the recipient of the 2005 California Pacific Medical Center (CPMC) Foundation Wishes for Wellness Grant. Through this grant, PFC will embark on a research project assessing the efficacy of a new IVF egg freezing method, vitrification.

The CPMC Foundation selects outstanding CPMC physicians in the fields of obstetrics and gynecology and pediatrics to be honored at their event Wishes for Wellness. PFC’s Eldon Schriock, MD and Carl Herbert, MD were among those selected in 2005. These honored physicians have the privilege of identifying needs and/or directing purchases and programs which will be funded by the Wishes for Wellness Grants.

Egg freezing has been successful in creating a handful of pregnancies, but the process is still very inefficient. Many eggs do not survive the freezing process. While the technology for freezing sperm and embryos has been used for decades and is very successful, the technology for egg freezing is still emerging.

The key to successful egg freezing is determining a technique that will not damage the fragile chromosomes of the egg. The eggs in the ovaries are held in “suspended animation”, until they are stimulated to grow and ovulate. During this state, the chromosomes of the egg are vulnerable to damage, including damage from the exertion of the freezing and thawing process. Past freeze/thaw techniques have been very inefficient because of the chromosomal damage incurred. The vitrification freezing technique seems to be a gentler technique, and therefore leads to less chromosomal damage. This then improves efficiencies in the thawing, fertilization and embryo development steps; and ultimately better pregnancy rates.

Our study is designed to study whether vitrification can improve the efficacy of freezing eggs. The study is designed is such a way that results should be obtained in a timely manner. Egg donors who have had previous IVF cycles resulting in pregnancy will be recruited to have eggs frozen. The results of fertilization, embryo development, implantation and pregnancy rates using the embryos resulting from egg vitrification will be compared to the pregnancy rates obtained in previous cycles using embryos obtained from fertilized fresh eggs.

PFC is excited and honored to be involved in this research. The potential benefits of egg freezing are substantial and our research team looks forward to sharing results with you, as soon as they are available.

– Eldon Schriock, MD