Victoria M. Sopelak

Blockade of the estrogen-induced luteinizing hormone surge in monkeys: a nonsteroidal, antigenic factor in porcine follicular fluid*

That both follicular fluid extracts and ovarian hyperstimulation block estrogen-induced gonadotropin surges in primates has been established. In the present study, the differential actions of gonadotropin-releasing hormone (GnRH) and estradiol benzoate (E2B) on bioassayable LH (BIO-LH) secretion in the presence of a porcine follicular fluid (pFF) extract were assessed. Further, the inherent immunogenicity of the follicular fluid factor(s) that block estrogen-induced surges was examined. In castrated monkeys, administration of Florisil/charcoal-extracted pFF did not affect BIO-LH secretion induced by exogenous GnRH, although the pFF extract abolished E2B-induced BIO-LH surges. In monkeys given pFF chronically (for 6 to 8 months), immune responses capable of neutralizing the inhibitory actions of pFF on the E2B-induced BIO-LH surges developed. In these pFF-immunized monkeys, the BIO-LH surge induced by an E2B challenge was restored despite concurrent pFF injections.

Contralateral tubal-ovarian apposition and fertility in hemiovariectomized primates*

Here, we examined longitudinally (1) the incidence of pregnancy in hemiovariectomized macaques possessing only one ovary contralateral to a single fallopian tube, i.e., pregnancy after transabdominal ovum migration; (2) the pregnancy rate after surgically achieving contralateral apposition of the ovary and fallopian tube; and (3) the frequency of ovulatory menstrual cycles, patterns of menstruation, and steroid profiles in serum of intact versus hemiovariectomized monkeys to determine whether the ovarian cycle is altered by constraining recurrent follicular maturation and corpus luteum function to one ovary. Despite matings during 28 ovulatory menstrual cycles, none of the five primates possessing only one ovary contralateral to a single fallopian tube became pregnant. In contrast, following contralateral tubal-ovarian apposition, three of these five monkeys conceived after only nine ovulatory menstrual cycles. Hemiovariectomy of monkeys did not compromise the regularity of menstrual cycles or frequency of ovulation, compared with intact control females over the 13-month interval of study (P greater than 0.01). Thus, tubal-ovarian apposition is required in these primates for efficient ovum pickup and fertilization and deserves further clinical scrutiny for women having one functional ovary and one healthy fallopian tube, albeit contralateral.

Elevated luteinizing hormone on the day of human chorionic gonadotropin administration does not reduce cycle fecundity in a low-dose flare-up in vitro fertilization protocol**Supported in part by the Vicksburg Hospital Medical Foundation, Vicksburg, Mississippi.††Presented at the Conjoint Meeting of The American Fertility Society and the Canadian Fertility and Andrology Society, Montreal, Quebec, Canada, October 11 to 14, 1993.

OBJECTIVE To determine if elevated LH at the time of hCG administration occurs and adversely affects success in a low-dose gonadotropin-releasing hormone analogue (GnRH-a) flare-up protocol in hMG-stimulated IVF cycles. DESIGN Pearson correlation matrix analysis of hormonal, gamete, and clinical data derived from 203 consecutive IVF cycles was performed. All patients were treated with low-dose GnRH-a (250 micrograms SC leuprolide acetate) and hMG. In 203 consecutive IVF cases, serum was obtained on the day of hCG administration and assayed for E2, LH, and P. These data were correlated with peak E2, number of follicles, oocytes, embryos, and conceptions. Additionally, patients with elevated LH were compared with the nonelevated LH group. RESULTS Twenty six women had LH > 35 mIU/mL (mean +/- SEM; 51.1 +/- 1.9) and five pregnancies (cycle fecundity 19.2% per retrieval). One hundred seventy-seven patients had LH < 35 mIU/mL (16.3 +/- 0.5) and 25 pregnancies (cycle fecundity 14.1%). There were no differences in the mean P (1.0 +/- 0.1 ng/mL, conversion factor to SI unit, 3.81) and E2 (1,672 +/- 144 pg/mL, conversion factor to SI unit, 3.671) of the former group compared with the P (1.1 +/- 0.07 ng/mL) and E2 (1,456 +/- 69 pg/mL) of the latter group. There was no correlation with the number of follicles, oocytes, embryos, pregnancies, E2, or P to LH concentration (rmax = 0.132). CONCLUSION In a low-dose, GnRH-suppression, IVF induction protocol, elevated LH occurs in a small subset (13%) of women at the time of hCG administration. This event does not appear to alter cycle fecundity nor induce premature luteinization.