William K. Vaughn

Comparison of human menopausal gonadotropin, clomiphene citrate, and combined human menopausal gonadotropin-clomiphene citrate stimulation protocols for in vitro fertilization

Human menopausal gonadotropins (hMG) and clomiphene citrate (CC), either alone or in combination, are frequently used for in vitro fertilization (IVF) in an attempt to maximize the number of oocytes recovered and the number of embryos transferred. However, direct comparison of the relative efficacy of these protocols in the same institution has been limited. To evaluate this question, the authors examined the outcome of 304 consecutive women attempting IVF. One hundred eighty-one women received hMG, 42 received CC, and 81 received combination hMG/CC. The percentages of women undergoing laparoscopy were not different among the groups (69%, 71%, and 74%, respectively), nor were the rates of oocyte recovery (94%, 100%, and 100%). However, the percentage of women achieving oocyte fertilization (77%, 83%, and 93%) and embryo transfer (73%, 83%, and 90%) were significantly greater among those who had received hMG/CC stimulation. A comparison of hMG/CC with hMG and CC cycles revealed a statistically significant increase in the total number of developing follicles (4.5 +/- 0.3, 3.3 +/- 0.2, and 3.1 +/- 0.3, respectively; P = 0.0137), total oocytes recovered (4.1 +/- 0.3, 3.2 +/- 0.2, and 2.5 +/- 0.2; P = 0.0011), and embryos transferred (2.2 +/- 0.2, 1.4 +/- 0.2, and 1.4 +/- 0.2; P = 0.0013). However, there was no significant difference in the occurrence of ongoing pregnancies. Thus, in terms of the per-patient number of follicles, oocytes, and embryo transfers, combined hMG/CC stimulation appears to be superior to either hMG or CC alone. However, to date the combined regimen has not improved pregnancy rates.

Reassessment of White's classification and Pedersen's prognostically bad signs of diabetic pregnancies in insulin-dependent diabetic pregnancies

The classification systems developed over 20 years ago by White and Pedersen identified diabetic pregnancies at increased risk for perinatal mortality. To assess whether these same criteria would currently be valid, 199 diabetic pregnancies with deliveries from 1977 to 1983 were reviewed. Perinatal mortality rates for Whites Classes B gestational (n = 72), B (n = 27), C (n = 67), and D + F + R (n = 33) were 2.9%, 11.1%, 14.9%, and 21.1%, respectively (p less than 0.05). Whites classes were also predictive of pulmonary morbidity (12.5%, 18.5%, 22.4%, and 42.4%, respectively). The presence of one or more of the prognostically bad signs of pregnancy (n = 76) increased the perinatal mortality rate to 17.1% versus 7.3% among insulin-dependent diabetic pregnancies without prognostically bad signs (p less than 0.05). The presence of any prognostically bad signs of pregnancy was also predictive of pulmonary morbidity in general (31.6% versus 16.3%, respectively) and hyaline membrane disease in particular (13.2% versus 4.1%, respectively). Thus with use of modern obstetric management and medical care of the pregnant diabetic patient, both Whites classification and Pedersens prognostically bad signs of pregnancy continue to be predictive of perinatal mortality.

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.

The effect of the incubation temperature on the cleavage rate of mouse embryos in vitro

We have studied the effect of an elevated incubation temperature on the in vitro cleavage rate of one- and two-cell mouse embryos. Two-cell embryos demonstrated a significantly higher rate of cleavage when incubated at 39°C as compared to 37 or 41°C. When recovered at the onecell stage, the difference in cleavage rate between the groups incubated at 37 and 39°C did not reach significance. While the morphology of the embryos incubated at 37°C did not differ from that of the embryos incubated at 39°C in either group, a significantly higher rate of degeneration was noted in the group of two-cell embryos incubated at 41°C. These findings may apply to the human in vitro fertilization and embryo transfer system (IVF-ET), where the existing “lag” between embryo and endometrium could be narrowed if embryo cleavage rates could be accelerated. Further documentation of the normality of these “advanced” embryos is required.

Selection of superior stimulation protocols for follicular development in a program for in vitro fertilization

Classification of stimulated controlled follicular development cycles in programs for in vitro fertilization by the likelihood of culminating in a pregnancy would allow for increased efficacy in patient management and the distribution of care provider services. Analysis of human menopausal gonadotropin stimulations by the estradiol (E2) patterns identified trends suggesting superiority of one pattern, but no statistically significant difference was identified. Similarly, trends were identified in the Norfolk data for the height and pattern of E2 response, but no statistical significance was identified. While these observations may become significant with larger numbers, until that time, criteria for altering patient management based on the rise of follicular phase E2 levels should be reconsidered.

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<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.

Congenital Anomalies in Offspring of Insulin-Dependent Diabetic Mothers

Congenital malformation continues to be a major problem for infants of diabetic mothers. Over a seven-year period, 199 insulin-requiring diabetic mothers were delivered at Vanderbilt University Medical Center. Con genital anomalies were identified in 26 (13%) newborns. There was no significant difference in the incidence of fetal anomalies between the various categories of Whites classification of maternal diabetes mellitus. A review of proposed etiologies of anomalies in diabetic pregnancies is presented, and suggestions are made for the manage ment of women with dia betes desiring to conceive.

Combination clomiphene citrate/human menopausal gonadotropin stimulation protocols for in vitro fertilization-embryo transfer

Various protocols have been utilized for stimulation of multiple ovarian follicles in patients undergoing in vitro fertilization-embryo transfer (IVF-ET). Previous studies have suggested that the combination of clomiphene citrate (CC) and human menopausal gonadotropins (hMG) is superior to either CC or hMG alone in terms of follicular development, oocyte recovery, and embryo transfer. However, no significant increase in viable pregnancy rates has been reported with any of the protocols. This report examines five different CC/hMG protocols. While differences were seen in terms of serum estradiol response and fertilization rates of mature oocytes among the various protocols, no significant differences were found in terms of follicular development, oocyte recovery, embryo transfer, or pregnancy. The pregnancy rate in IVF-ET appears unaffected by variations in the dose and timing of CC and hMG in a combination protocol.