In vitro fertilization and embryo transfer program, Department of Obstetrics and Gynecology, University of Adelaide at the Queen Elizabeth Hospital, Woodville, South Australia

Polycystic ovarian syndrome and the risk of spontaneous abortion following assisted reproductive technology treatment

BACKGROUND

A high proportion of infertile patients have polycystic ovarian syndrome (PCOS) with a reportedly greater risk of spontaneous abortion. Because of the close link between PCOS and obesity and the independent association of obesity with poor pregnancy outcomes, it is important to distinguish the possible confounding effect of body mass index (BMI) or other variables from that of PCOS. This study aims to determine the effect of PCOS status on the risk of spontaneous abortion with adjustment for body mass and several other confounding factors in a large cohort of pregnant infertile women.

METHODS

The patients (n = 1018) were treated in a tertiary infertility centre. Their PCOS status was determined by standard criteria and their BMI had been taken less than 1 year before the pregnancy. Patients whose PCOS status or BMI measurements were not assessed were excluded. Student's t-test or chi2 test were used to test the difference between the PCOS and non-PCOS groups while a multivariate logistical regression model was used to assess the effect of PCOS, BMI and other confounding factors.

RESULTS

Overall, the incidence of PCOS was 37% in this cohort. The overall incidence of spontaneous abortion in the study population was 21%. Univariate analysis showed that women with PCOS had a significantly greater risk of spontaneous abortion compared with non-PCOS women (25 versus 18%, P < 0.01). However, using multivariate logistic regression analysis this effect was reduced to a non-significant level [odds ratio (OR) = 1.10, 95% confidence interval (CI) 0.85-1.36] after adjusting for obesity and patients/treatment combination factor, and to nil after adjusting for all confounding factors considered in this study (OR = 0.98, 95% CI 0.75-1.28).

CONCLUSION

The results of this study suggest that the higher risk of spontaneous abortion observed in women with PCOS is likely to be due to their high prevalence of obesity and the type of treatment they receive.

ICSI outcome in patients of 40 years age and over: a retrospective analysis

OBJECTIVE

To report and analyse our experience with ICSI treatment in infertile women >/=40 years of age, with the intention of contributing to current debates on the effect of aging on the reproductive potential.

STUDY DESIGN

107 infertile couples in which the female partner was aged >/=40 years and who received ICSI treatment between January 1996 and December 1998.

RESULTS

A total of 107 women underwent 171 treatment cycles during this period. Of 171 cycles initiated 33 were cancelled (cancellation rate=19.3%). In this way, 17 women did not have embryo transfer at all, while 90 patients had 138 cycles with oocyte retrieval and successful embryo transfer, with a mean number of embryos per transfer 2.36. Sixteen pregnancies occurred and eight of them ended in spontaneous abortion. The implantation rate was 4.9%, the pregnancy rate per initiated cycle was 9.35% and per transfer cycle 11.59%. The miscarriage rate was 50%. Moreover, 12 patients had supernumerary embryos, that were cryopreserved and transferred in 17 thawing cycles and resulted in two pregnancies ending in abortion. All pregnancies occurred when three embryos were available, except in two cases with two available embryos. The great majority of the total pregnancies (16 of 18) resulting in women aged between 40 and 42 years.

CONCLUSION

Our data show that women 40 and older with existing ovarian function may benefit from ICSI treatment, even when the indication for treatment is male factor infertility. Supernumerary embryos, that are cryopreserved and transferred in subsequent cycles can improve the overall pregnancy rates per oocyte retrieval, although these women should be aware of the very high risk of miscarriage.

Female aging and superovulation induction for IVF

The success of in vitro fertilization (IVF) has been reported to be adversely affected by increasing women's age. The main reason being that older women more frequently show a poorer response to stimulation. Information about such variability in ovarian responsiveness to stimulation is important for assessing the chances for successful pregnancy in older women undergoing assisted reproduction, because those with limited ovarian reserve should be counseled to consider other therapeutic options without delay. I present results demonstrating the ovarian response to gonadotropin stimulation and the success rate in 746 IVF cycles. A brief overview on current methods of evaluating ovarian reserve as a means to identify the poor responder, and a discussion on the efficacy of several stimulation regimens for old women with limited ovarian reserve is also provided.

The end of fertility: age, fecundity and fecundability in women

Onset of capacity for childbearing in women is dated biologically by menarche, although actual onset may be delayed. The end of childbearing is less understood but recent demographic and biological research on fertility at older ages in clarifying the end of fertility. The demographic view of declining fertility with age is based on age-specific fertility in natural fertility populations, artificial insemination and pregnancy rates by age and World Fertility Survey data. New data from the Demographic and Health Surveys on exposure to the risk of pregnancy shows that whereas older women biologically need longer exposure to pregnancy, exposure declines on behavioural grounds such as duration of marriage. Actual fecundity is obscured by factors of fecundability. Recent research on medically assisted conception is adding to the understanding of declining fecundity with age, especially the relative contributions of endometrial and ovarian ageing. This paper reviews the available information on declining fertility with age and discusses the implications of the extension of fertility through new medical technologies.

Comparative trial of clomiphene citrate/human menopausal gonadotropin and the contraceptive pill, followed by clomiphene citrate/human menopausal gonadotropin, in a gamete intrafallopian transfer program

PURPOSE

It may sometimes be necessary to regulate cycles in assisted reproduction. Cycles can be regulated with gonadotropin releasing hormone (GnRHa) agonist but other methods can also be used. The aim of this study was to compare the pregnancy rate in a gamete intrafallopian transfer (GIFT) program in patients receiving a contraceptive pill/Clomid/human menopausal gonadotropin (hMG) regimen (study group), with the standard Clomid/hMG regime (control group). Fifty one patients in the study group were carefully matched for patient age, infertility diagnosis (female), semen parameters, number of follicles, and number of oocytes transferred into consideration with a control group.

RESULTS

The overall pregnancy rate was 21.6% (11/51) in the study group and 47% (24/51) in the control group (P = 0.01). However, the ongoing pregnancy rate in the two groups did not differ significantly, 11.8% (6/51) vs 27.5% (14/51) (P = 0.08). In the study group, 7.8% of patients had to be seen over a weekend, compared to 13.7% in the control group (not significant).

CONCLUSION

From the findings we conclude that, although this method of controlling cycles can be useful in selected patients, it is not the ultimate method.

Age and pregnancy rates in in vitro fertilization

The influence of women's age on the results of in vitro fertilization (IVF) was analyzed in 1801 women undergoing the procedure. Advancing age was found to be related to significant reduced success rates from an average of 30.1% per transfer below the age of 36 years to 15.9% per transfer at 37 years or more (P less than 0.001). The decrease was related to a reduction in oocyte production (five at 25 years or less, four below the age of 40 years, three at 40 years or more, and two in the 43 to 47-year group) and probably due to reduced implantation. It is concluded that a woman's age must be considered an important prognostic factor when IVF is suggested.

The impact of embryo quality on pregnancy outcome in elderly women undergoing in vitro fertilization-embryo transfer (IVF-ET)

Most IVF-ET units limit the procedure to women below age 38. Nevertheless, demands for infertility treatment, including IVF therapy, are more frequent nowadays. We compared 46 cycles for ovulation induction for IVF in 46 women aged 40 or more (Group I) to 51 induced cycles for this procedure in younger women of mean age 30.2 years (Group II). Cancellation rates due to early luteinization or ovulation were significantly higher in group I than in group II (28.2 and 17.6%, respectively) (P less than 0.001). Also, significantly higher abortion rates were observed in older women (62.5%), in comparison to the younger control group, (25%), (P less than 0.001). It is suggested that the high abortion rate considered to be due to genetic factors in older women, may possibly also be due to the aging uterine environment. Furthermore, while embryos with fragmentations may often produce clinical pregnancies in the young, the aging uterus in the elderly woman does not encourage the development of clinical pregnancies in such embryos. Consequently the higher abortion rate in the elderly woman.

Patient age and success in a human IVF programme

Previous studies suggest that at around 40 years of age, pregnancy rates achieved by IVF programmes fall and pregnancy loss rates increase. The actual age at which this occurs has not been clearly delineated. This study of 2,692 patients including 94 aged 41 or over shows that satisfactory pregnancy rates can be achieved up to and including age 40. As age 40 is approached the pregnancy loss rate increases to around 40%. In the 41 years and over group the pregnancy rate was poor at 6% (6/94) and the pregnancy loss rate very discouraging at 83% (5/6).

The effect of transferring pronuclear embryos on pregnancy outcome after in vitro fertilization

In a prospective clinical trial the pregnancy rate in patients matched for infertility status, degree of hyperstimulation, and number of oocytes recovered was unaffected by whether embryos were transferred while still pronuclear (day 1) or after they had undergone cleavage (day 2). The pregnancy rates per transfer were 27% and 22%, respectively, for the two transfer times. Unlike results of a previous study, no difference was detected in the outcome of pregnancies from the two groups.

Endocrine changes in the late-follicular and postovulatory intervals as determinants of the in vitro fertilization pregnancy rate

This investigation examines the hormone pattern in in vitro fertilization (IVF) cycles from the time of human chorionic gonadotropin (hCG) administration through embryo transfer to ascertain whether the absolute levels or secretory patterns of the major reproductive hormones affect the IVF pregnancy rate. Thirty-one women who underwent IVF treatment were enrolled in the study. All patients received clomiphene citrate/human menopausal gonadotropin for ovulation induction. Significant elevations in serum estradiol (E2) levels in the pregnant group were found throughout the cycle interval studied. After hCG administration the serum hCG levels were not different between the groups. Significant elevations in serum progesterone (P) concentrations were found in the pregnant group from the day after laparoscopy through embryo transfer. Embryos obtained from the pregnant group appeared to be different in that the mean number of blastomeres per embryo transferred was significantly greater. Therefore for achievement of an IVF pregnancy the optimal hormone pattern employing combination ovulation induction in the ovulation to transfer interval is a relatively high E2 level in ovulation followed by a high P level at transfer and into the luteal phase. These elevated hormone levels do not depend on the response to exogenous hCG.

Results of in vitro fertilization attempts in women 40 years of age and older: the Norfolk experience

Twenty-nine patients 40 years of age or older were stimulated with gonadotropins, starting on day 3 of the cycle, in a total of 64 cycles (January 1983 to June 1985) for multiple follicular development for in vitro fertilization. Most patients' infertility was due to tubal disease (n = 8) or pelvic endometriosis (n = 14). The mean number of preovulatory and immature oocytes recovered per laparoscopy was 2.53 +/- 1.73 and 1.57 +/- 1.58, respectively. There were no statistically significant differences between the number of preovulatory and immature oocytes harvested, fertilized, or transferred in this group and the number in patients younger than 40 years of age. No statistically significant differences were observed between peripheral estradiol and progesterone levels in patients 40 years of age or older and levels in patients 39 years of age or younger. There were 15 pregnancies in this group of patients, for a pregnancy rate of 23.4% per stimulated cycle, 27.7% per laparoscopy, and 29.4% per transfer. The ongoing pregnancy rate (12%) was lower, and the total abortion rate (60%) was higher, in patients 40 years of age or older in comparison with patients 39 years of age or younger. Patients 40 years of age or older should be counseled regarding the high abortion rate in this group.

Undetected ovulation in in vitro fertilization-embryo transfer patients

A retrospective evaluation was done of 102 consecutive in in vitro fertilization-embryo transfer (IVF-ET) treatment cycles that culminated in surgical intervention for oocyte pickup. In 35% of these patients, a disparity was noted in the number of mature follicles present on the day of human chorionic gonadotropin administration, compared with the day of surgery. This suggests the occurrence of undetected ovulation. An endogenous luteinizing hormone (LH) surge was detected in 14 of these patients. Another cohort showed evidence of early luteinization without a detected endogenous LH surge. Finally, a group without early luteinization was defined. Possible explanations for these outcomes and the implications for success of IVF-ET are discussed.

Comparison of two brands of clomiphene citrate for stimulation of follicular development in a program for in vitro fertilization

Although clomiphene citrate (CC) is used frequently to stimulate multiple follicular development in in vitro fertilization programs, comparison of the two commercially available types has been limited. Therefore, a comparison was made of Serophene (Serono Laboratories, Inc., Randolph, MA) and Clomid (Merrell Dow Pharmaceuticals, Inc., Cincinnati, OH), using the same dosage regimen of CC (150 mg/day for days 3 to 7 of the cycle). Weights and ages of the two groups were not different. Serum estradiol (E2) levels were significantly elevated in Clomid cycles, but the number of developing follicles was not different between the two brands. The percentages of patients in each group who underwent laparoscopy, oocyte recovery, oocyte fertilization, and embryo transfer were also equivalent. Among patients undergoing laparoscopy, no differences in oocyte recovery, oocyte fertilization, and embryo development were noted. Thus, despite greater elevation of serum E2 levels with Clomid, no difference in stimulation regimen outcome was observed.

Antiestrogenic effect of clomiphene citrate in a multiple follicular stimulation protocol

End-organ antiestrogenic effects of clomiphene citrate (CC) have been demonstrated in the female reproductive tract at the levels of the ovary, cervix, and endometrium. However, it has not been established whether this effect is manifested during concomitant human menopausal gonadotropin (hMG) administration, as occurs in hMG/CC stimulations of multiple follicular development. To assess this question a review was made of serum estradiol (E2) and cervical mucus in 47 hMG and 56 hMG/CC stimulations on days -2, -1, 0, and +1 relative to the day of hCG administration. E2 levels (pg/ml) were significantly lower in the hMG as compared to the hMG/CC group. However, comparing the hMG and hMG/CC groups, cervical mucus scores were significantly higher in the former. Furthermore, an analysis of covariance demonstrated that the cervical mucus scores on each day were significantly lower in the hMG/CC group (P less than 0.001). Thus, in hMG/CC stimulations for in vitro fertilization (IVF), despite the concomitant administration of pharmacologic doses of hMG, CC exerts an antiestrogenic effect on at least one end organ, cervical mucus production. Potentially, this antiestrogenic effect in IVF stimulations would be exerted at other female reproductive tract sites including the endometrium; however, its clinical significance, if any, is unclear.

Experience with the cryopreservation of human embryos using the mouse as a model to establish successful techniques

Mouse embryos at the one-, two-, and eight-cell stages have been used to optimize the conditions for cryopreservation of human oocytes and embryos. For storage in glass vials using 1.5 M dimethyl sulfoxide (DMSO) as a cryoprotectant and slow cooling (approximately 0.3 degrees C/min), phosphate-buffered medium was superior to Hepes-buffered medium. Termination of slow cooling at -80 degrees C before transfer to liquid nitrogen with subsequent slow thawing (approximately 8 degrees C/min) resulted in more embryos surviving than when cooling terminated at -40 degrees C and rapid thawing (approximately 500 degrees C/min) was employed. Dilution of DMSO upon thawing with medium containing 0.5 M sucrose gave higher embryo survival rates than a stepwise (0.25 M decrements) dilution. Using these techniques, three pregnancies were established upon the transfer of 11 frozen-thawed embryos to seven patients. Rates of embryo survival using the simpler cryopreservation technique of ice-free vitrification in 0.25-ml straws have been disappointing.

Relationships between embryo transfer results and ovarian response and in vitro fertilization rate: analysis of 186 human pregnancies

We studied the relationships between "pretransfer" parameters (number of follicles, oocytes, and embryos) and the result (occurrence and quality of pregnancy) obtained by transferring one, two, or three embryos. The analysis concerns 186 pregnancies compared with 186 implantation failures. The chances for an oocyte to cleave or for a pregnancy to continue decreased when the number of preovulatory follicles increased. The number of transferred embryos increased with oocyte cleavage rate in nonpregnant patients and in patients with an ongoing pregnancy, but such a relation was not found in the case of failed pregnancy (biochemical pregnancies and abortions). Failed pregnancies occurred in patients who demonstrated the highest oocyte cleavage rate (94.1%), compared with 81.2% for implantation failure and 84.8% for ongoing pregnancy (P less than 0.01). The cleavage rate was also higher in cases of multiple, compared with single, ongoing pregnancies after the transfer of three embryos (79.7% versus 64.5%, P less than 0.001). An important finding was the higher survival rate after triple-embryo transfer in patients, yielding numerous oocytes. The survival rate (fetuses per transferred embryos) after the transfer of three embryos was 14.9% in patients yielding five oocytes, versus 7.7% in patients yielding 3.4 oocytes (P less than 0.05). These results are related to oocyte and embryo viability and uterine ability for pregnancy.

Effect of the number of inseminating sperm and the follicular stimulation protocol on in vitro fertilization of human oocytes in male factor and non-male factor couples

The effect of sperm concentration and follicular stimulation protocol on in vitro fertilization of human oocytes is not well established. Comparison was made of three inseminating concentrations (250,000, 375,000, and 500,000 progressively motile sperm/oocyte) and three protocols (human menopausal gonadotropin [hMG], clomiphene citrate [CC], and combination hMG/CC) on the fertilization rate of mature and immature oocytes in couples with male factor and non-male factor infertility. In non-male factor couples, total fertilization rates for CC, hMG, and hMG/CC were 70.3%, 54.5%, and 68.8%, respectively, while total fertilization rates at the varying number of inseminating sperm were not significantly different. Mature oocytes were more likely than immature oocytes to fertilize. Among semen male factor couples, there was no difference in fertilization by stimulation protocol; however, insemination with the higher number of inseminating sperm resulted in an increased fertilization rate.

Polyspermy: effect of varying stimulation protocols and inseminating sperm concentrations

Results from 198 cycles of in vitro fertilization (IVF) were examined to identify factors in the subsequent development of polyspermy. Polyspermy occurred in 24 of 235 fertilized oocytes and was equally likely in mature and immature oocytes. No significant difference in polyspermy was demonstrated between the stimulation protocol using human menopausal gonadotropin (hMG) and those using clomiphene citrate (CC) or combined hMG/CC. The incidence of polyspermy was no different after insemination of oocytes with concentrations of progressively motile sperm ranging from 250,000 to 500,000. Although polyspermy continues to be a problem in IVF, we have been unable to identify possible predisposing mechanisms for its development.