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.  

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.

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 #5 Men and ART

The Mental Health Professional Group (MHPG) course entitled Men and ART: The Missing Voice, blended medical, psychological, ethical and legal information relating to men who participate in Assisted Reproductive Technology (ART).

The legal issues confronting single men and gay men considering the use of egg donors and gestational surrogates continue to be controversial. Adoption legislation in many states prohibits gays and lesbians from adopting. In a study reported in 2005 by Gurmankin, et. al, 44% of ART programs responded that they would not turn away gay couples seeking surrogacy with one partner’s sperm and 48% responded that they would turn them away. This is in contrast to the higher rate of acceptance of lesbian couples. In lesbian couples seeking treatment using donor insemination, 82% of ART programs agreed to treat versus 17% who refused to treat them.

Though often presented exclusively to women, men can also benefit from the use of stress reduction strategies and following a healthy life style which includes regular exercise, normal body weight, no smoking or recreational drug use and avoidance of environmental toxins. In addition, the effects of aging and cancer on sperm quality should not be overlooked when men seek reproduction assistance. (See articles on: Sperm Aging: Fertility Flash Feb. 2004, Sperm Fragmentation: Fertility Flash March 2005, Cancer and Infertility: Fertility Flash Oct. 2004).

The psychological component of this course was compelling. Approximately 50% of cases of infertility involve at least some degree of male infertility. Why is it that most infertility references are traditionally directed at women? By definition, Infertility is “…the inability of a woman to conceive after some months (12-24) without contraception, or the inability to carry a pregnancy to term.” (Institute of Medicine and National Research Council, 1989). Ancient biblical references and popular literature focus on women’s infertility – e.g. Sarah and Hannah in the bible, Sylvia Plath’s Barren Woman, Jane Smiley’s 1000 Acres. The list is long. Google hits by gender for infertility and psychology show 542,000 for men and 700,000 for women.

The cause of this discrepancy is multifaceted. There are fewer psychological studies on men simply because men have a lower study response rate than women. A variety of successful techniques have been developed to overcome male related medical issues. Additionally, most men spend less time in treatment and experience fewer invasive procedures than women. In general, it is more socially acceptable for women to express their feelings regarding infertility. The opposite is true for men whose fertility often is a taboo topic. Furthermore, some cultures protect their men from the unacceptable stigma of infertility and even falsely describe men as having “poor” coping skills.

Despite these discrepancies, men do have feelings about infertility and may need support and assistance to better cope with the diagnosis. A study by Mason MC in 1993 found that men felt guilt, shame, anger, isolation, loss and a personal sense of failure. This is not all that different from what women feel, but each individual’s coping mechanism is unique. We all, however, find ways to protect ourselves from what we perceive as painful information.

These coping skills can be divided along gender lines. There are ways that many, but certainly not all, men commonly protect themselves from the pain related to his or his partner’s infertility diagnosis. Frequently men are able to distance themselves from the feelings. They appear to have the ability to take painful information and put it in a little box that they then file away in the back of their minds. The box stays tightly shut. Other men want to problem-solve for their partner or avoid the topic completely, throwing themselves into work or hobbies. Some men become extremely optimistic to avoid or counter their partner’s pessimism.

These are different styles- not right or wrong. For many of us, particularly women, the closed box technique does not work. The box is opened often, and feelings appear to refuse to stay tucked away. When partners have different coping styles, it’s important to both learn to tolerate and support these differences. Sometimes that is easier said than done…

Peggy Orlin, MFT

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

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

Introduction

Sara (a hypothetical patient) found a breast lump. 36 years of age, she was a single active professional, otherwise healthy, careful about her diet, and carefully evaluating her options after a diagnosis of breast cancer. Along with the discussion on surgery, chemotherapy, and radiation therapy came the question “Were you planning to have children?”

A diagnosis of cancer presents many decisions that must be made quickly. Confirming the diagnosis and planning therapy will be the primary concerns, but the implications of therapy on long-term quality of life must be assessed. One of the primary issues facing women with a diagnosis of cancer is future fertility.

Candidates

Cancer treatment can interfere with future fertility. Toxicity varies by treatment. Cyclophosphamide, an alkylating agent used in many chemotherapy regimens, is highly toxic to sperm and eggs; methotrexate and 5-flouro-uracil (5FU) are not. Medications used for longer time intervals create a higher risk of fertility problems than shorter time intervals; effects on women in older age groups are more severe than younger. Radiation therapy, in high doses, can have effects on eggs and sperm. Surgery and anesthesia are not known to have direct effects.

It is difficult to give specific fertility risks for chemotherapeutic regimens, since studies are not yet definitive. Among the more toxic treatments are stem cell transplantation for leukemia in which total body irradiation and cyclophosphamide are used, beam radiation to a field that includes the ovaries, and extended chemotherapy of up to 6 cycles using cyclophosphamide in combination with other agents. After conventional chemotherapy for breast cancer for women under 40, the chance of infertility is roughly 50%, in older women the risk is over 80%.

Treatment options

What are the options for fertility in patients diagnosed with cancer? The best choices are available to those that have not yet initiated treatment and involve cryopreservation. During treatment, the risk of problems rises, and after treatment, there may not be adequate recovery of fertility to achieve pregnancy.

Cryopreservation allows cells to be stored with great stability for long periods of time. The record time from sperm cryopreservation to pregnancy is 28 years; there probably is no real limit to the time that cells can be stored. To store cells requires technology that reduces the formation of ice crystals, which disrupt cells, and prevents the rapid rise in salt concentration that occurs as water freezes. Cryopreservatives and management of temperature changes (slow freeze or vitrification) are used to reduce the risk of these problems.

Male

The option for fertility preservation in men is straightforward, cryopreservation of sperm. Sperm is obtained by masturbation and frozen in multiple vials in liquid nitrogen. 2-3 sperm samples can be obtained per week, with 2-4 vials stored per ejaculate; two weeks worth of donations could yield 8-24 vials of sperm. Costs vary widely, but would range from $1500-$3000 for processing and 3 years of storage.

Testicular sperm extraction is an option for individuals with azoospermia. Testicular tissue cryopreservation remains a theory that has not yet produced a human pregnancy. It has been proposed as an option for preservation of fertility in children, but has yet to be proven in clinical practice.

Female

Women have the option of cryopreservation of oocytes or embryos. For women without a partner, oocyte cryopreservation holds promise as a means to preserve fertility potential without committing to a specific sperm source or partner. For women with a partner or sperm donor, embryo cryopreservation is a proven technology.

To create cryopreserved oocytes, Follicle Stimulating Hormone (FSH) is administered over a ten day time period to stimulate ovarian follicles. The oocytes are retrieved under sedation with a needle guided by ultrasound and then stored in liquid nitrogen.

Newer techniques of oocyte vitrification secure good pregnancy rates for those with good oocyte quality. Traditional oocyte cryopreservation is performed using a slow freeze technique, but more rapid vitrification procedures optimize results. The trick with cryopreservation is to lower the temperature while avoiding ice crystals that disrupt cell membranes and proteins. Vitrification, an ultrarapid freezing process utilizing a minimal fluid volume, reduces the risk of these problems and optimizes cell quality.

For those women with a partner, or that are willing to commit to a specific sperm donor, embryo cryopreservation is an excellent option. After stimulation and retrieval, oocytes are inseminated and cultured in an incubator for 1-5 days, followed by cryopreservation. The embryos can be thawed and transferred at a later date, after clearance from the oncologist. Embryo cryopreservation is the best established of the fertility preservation techniques, with years of experience in its applications. Good pregnancy rates can be anticipated.

Ovarian tissue cryopreservation, the cryopreservation of whole pieces of the ovary, as opposed to cells, remains experimental. Complex tissues are more difficult to cryopreserve than cells, though rare success has been reported.

Cancer recurrence

Is there risk to the use of fertility drugs in patients with cancer? It does not appear in studies to date that breast or ovarian cancer risk is affected by use of fertility drugs. Studies indicating an increased risk are balanced by other studies indicating a reduction in risk. Studies to date have been limited, and treatment decisions still must be individualized.

Does pregnancy increase the risk of cancer recurrence? In theory, certain types of cancer could be aggravated by the hormones of pregnancy, but studies have not confirmed an overall risk. Certain types of cancer are less common in women that have delivered a pregnancy. Treatment decisions must be individualized, as future studies gather more information.

Pregnancy

Certain cancer treatments create organ toxicity that must be evaluated in considering patients for pregnancy. Heart output is limited in patients that have received doxorubicin. Uterine irradiation is associated with miscarriage and pre-term labor.

Children

Children born after fertility preservation procedures do not carry any increased risk for birth defects. There are hereditary syndromes that can be associated with cancer that could be transmitted to children, but there does not appear to be any other increased risk for cancer or genetic disease in children of cancer survivors.

Patients contemplating conception must consider life span expectations as part of their decision on whether to conceive. Such considerations are not, however, a reason to withhold treatment, and are ultimately the individual and family should decide.

Philip E. Chenette, MD

Resources:

www.fertilehope.org Fertile Hope

www.livestrong.org Lance Armstrong Foundation

www.cryobank.com California Cryobank

www.PacificFertilityCenter.com Pacific Fertility Center

The first human pregnancy from an embryo that had been frozen and thawed was achieved in Australia in 1984, 6 years after the birth of the first IVF baby in the UK. The method used to preserve that embryo is called “slow freezing” and it is still the preferred method for preserving embryos throughout the world today. Slow freezing is a reliable and established technique that has served the IVF community well for over 20 years. The procedure has been refined throughout those years and it works, with slight modifications, for freezing all embryo stages and for sperm. However, despite many years of trying, slow freezing has never worked very successfully with oocytes. Frustrated by years of failures, scientists turned to an alternative procedure called vitrification in their quest to preserve oocytes. This approach is relatively new, but appears as through it will be preferentially used for oocyte preservation as we go forward. Vitrification kits are just beginning to get FDA clearance following scientific trials, and embryologists are being trained in the use of the new technology.

The main concern during the freezing of any cell is the removal of water without actually killing the cell. Since water expands in volume as it freezes, ice formation inside a cell would cause the cell to rupture and die. Therefore, cell water is traditionally replaced with a cryoprotectant (antifreeze) prior to cooling of the cell. This is achieved by sequentially incubating the cell in increasing concentrations of cryoprotectant. The cryoprotectant draws water out of the cell and itself enters the cell, all by osmosis. Once most of the water has been removed, the cell is cooled at the very slow rate of -0.3° C/minute until it has been cooled to below -30° C and is therefore fully frozen. Thereafter, storage of frozen cells is in liquid nitrogen (-196° C), which is a simple and practical storage medium.

Vitrification still requires the use of cryoprotectants and the cell is also ultimately stored in liquid nitrogen, but the journey from the incubator (at 37° C) to the nitrogen (-196° C) is much faster. The word “vitrum” in Medieval Latin means “glass” and the process turns the cell contents to a glass like substance instead of ice. Since no ice forms, the risk of rupturing the cell is eliminated. For glass to form instead of ice, the rate of cooling must be thousands of degrees per minute instead of the 0.3 degrees/minute that we use in slow freezing. Therefore, the process is sometimes referred to as ultra-rapid freezing, although the word “freezing” is really inappropriate here since the cell is not really frozen (i.e. no ice is created).

One of the big stumbling blocks during oocyte freezing was the sheer size of the cell (the oocyte is the largest human cell by some margin) and therefore its high water content. Just getting the cell to survive, (an oocyte has only one cell), was a huge stumbling block. Studies where 50-60% of the oocytes survived were considered groundbreaking, and still today there are few studies that have done better. Vitrification as a technique had been largely ignored by the IVF community as it was technically more challenging and used much higher concentrations of cryoprotectants. Cryoprotectants were thought to be toxic to cells. Today we know that they are safe and effective and do not contribute to cell death. It is possible that cryoprotectants may have deleterious effects on cells if they are metabolized, but virtually all freezing protocols utilize them at room temperature or below, where cell metabolism is significantly slowed or stopped. So, with success rates using traditional slow freezing failing to improve, vitrification has been given serious consideration as an alternative. In the few years since its introduction, vitrification has shown promising and excellent results in clinical studies (see Oktay et al., Fertility and Sterility, 2006, Vol 86(1), pages 70-80 a comparative review of slow freezing and vitrification results with human oocytes).

Making the transition from slow freezing to vitrification has been a challenge for the IVF community. As already stated, it is a technically challenging procedure, and training of embryologists in the technique has been slow. With slow freezing, embryos are placed in relatively weak solutions of cryoprotectant for as long as 15 minutes at a time. Then, they are usually moved on through slightly stronger solutions before being placed in large straws or vials which are then loaded into a computer controlled freezer for the long journey to -30° C. The embryologist can spend about 30 minutes with a set of embryos from the time that they come out of the incubator until they go into the controlled rate freezer. After 2 or more hours, the embryos can be placed in liquid nitrogen and the process is complete.

During a vitrification procedure, where typically only one oocyte or embryo can be worked on at a time, the transition from incubator to nitrogen takes only a few minutes. The embryo is stepped through solutions containing high and then higher concentrations of cryoprotectants where it shrivels and swirls in the extremely viscous medium. In the final stage, which is measured in seconds, the embryo is placed in an extremely concentrated cryoprotectant solution and then quickly loaded up into a tiny straw that is barely larger than the embryo itself. The straw is then sealed at both ends and plunged immediately into liquid nitrogen. The straw is so fine that it freezes in an instant, an important part of the vitrification process. The loading of the straw occurs at room temperature (25º C in the IVF lab) and it is cooled to -196º C in one or two seconds, giving a cooling rate of 6000-13000º C/min. The faster the straw can be cooled, the more successful the procedure. Performing this final step too slowly or too quickly can be the difference between success and failure and therefore requires extensive training.

At Pacific Fertility Center, we have been working on vitrification for over 2 years. Our initial interest was in oocyte freezing, but we were also interested in extending the technique to be used with embryos, and in particular to blastocyst stage embryos where slow freezing has not always worked well. Slow freezing has served us well over the years for embryos being frozen 1, 2 or 3 days after an oocyte retrieval, but blastocysts (5 or 6 day old embryos) did less well. With an industry wide transition to blastocyst stage embryo transfers, we looked at vitrification as an alternative method of preservation for these precious embryos.

A blastocyst is an embryo that has developed to the stage where it is ready to implant in the uterus. Instead of having a small number of loosely associated cells characteristic of earlier embryonic stages, it has 2 defined cell populations and a fluid filled cavity (or cyst). The cells that surround the cavity will form the placenta, and the cells within the cavity will develop into the embryo proper, or fetus and some of the extraembryonic membranes, such as the yolk sac. It is these interior cells that cause trouble during freezing since they are on the inside and difficult to expose to cryoprotectant. Slow freezing relies on cryoprotectant traveling through the outer placental cells, then the cavity, and finally into the fetal cells while water travels in the opposite direction. Fully dehydrating these fetal cells has always been a challenge and an embryo where these cells do not survive freezing and thawing will not result in a viable pregnancy. And with slow freezing, embryos tend to collapse in on themselves during dehydration, making it difficult to assess survival after thawing.

After investing heavily in vitrification training and implementing a successful oocyte vitrification program, PFC began working on blastocyst vitrification in January of 2007. By March we had a program established and were delighted by how easily blastocysts seemed to tolerate the procedure. Often, blastocysts looked no different after vitrification when compared to how they looked before the procedure. This result was in stark contrast to slow freezing where blastocysts always look shriveled and deflated after coming out of the freezer. By July 2007, we had switched completely to vitrification and currently we are enjoying the successes that it is bringing to our patients and us.

Our vitrification team consists of 3 embryologists: Mariluz Branch, the team leader, with Erin Fischer and Liz Holmes. Because of the technical challenges involved, we have to be cautious with involving other embryologists. So one of the three team members must be on duty every day (our lab is open 7 days a week). I am grateful to this team for their flexibility in accommodating our needs. By the end of the year we expect to have 2 more embryologists on the team, and then the final 3 in 2008.

Vitrification has been an exciting and challenging technique which we have embraced and conquered in 2007. We look forward to the gradual elimination of slow freezing and the successes that vitrification will bring us in the future.

Joe Conaghan, PhD, HCLD