Search

Purpose: Our purpose was (1) to determine if in vitro maturation of unstimulated oocytes could be improved with the addition of urofollitropin; (2) to evaluate the output of estradiol, testosterone, progesterone, and androstenedione by the cultured oocyte-cumulus complex; and (3) to ascertain if steroid hormone production of the oocyte-cumulus complex correlates with final oocyte maturation stage., Methods: Fifty-eight immature oocytes were obtained from 11 regularly cycling women undergoing oophorectomy. The oocyte-cumulus complexes were randomly assigned to control medium (Ham's F-10 supplemented with 7.5% fetal bovine serum) or test medium (control medium supplemented with 75 mIU/ml of urofollitropin)., Results: (1) The addition of urofollitropin to oocyte culture medium does not significantly increase the ability of the oocyte to achieve the metaphase II stage; (2) the addition of urofollitropin significantly increases the production of progesterone, testosterone, and androstenedione by the oocyte-cumulus complex; and (3) there is no difference in the production of estradiol, progesterone, testosterone, and androstenedione by the oocyte-cumulus complex at the germinal vesicle, metaphase I or metaphase II stage of oocyte maturation., Conclusions: This information is of importance in the use of oophorectomy specimens for patients who must undergo an oophorectomy but desire to attempt pregnancy using their oocytes, in the use of oophorectomy specimens for donor oocytes, or for patients undergoing in vitro fertilization using immature oocyte collection.

Purpose: Ovulation induction and oocyte retrieval were performed in a lowland gorilla in an attempt to propagate and potentially cryopreserve embryos from an infertile animal and to advance techniques to help preserve this endangered species., Results: Following 34 days of leuprolide acetate suppression, human menopausal gonadotropins were administered for 14-days in a 32-year-old wild-born lowland gorilla. Ten oocytes were retrieved by transrectal ultrasound-guided aspiration. Other approaches to oocyte recovery were not feasible in this case. A serum estradiol concentration of 4700 pg/ml at the time of human chorionic gonadotropin administration did not induce ovarian hyperstimulation. Mature oocytes were recovered from follicles measuring 14 to 24 mm in diameter, with a corresponding average serum estradiol concentration of approximately 300 pg/ml for each mature follicle. Cryopreservation of a gorilla embryo was effected from cryopreserved gorilla spermatozoa., Conclusions: Parameters for monitoring ovulation induction in the gorilla appear to be similar to those for humans. The results indicate that the use of a gonadotropin releasing hormone agonist and higher doses of gonadotropins than previously used in gorillas appear to improve oocyte recovery.

Anordiol (2 alpha,17 alpha-diethynyl-A-nor-5 alpha-androstane-2 beta,17 beta-diol) has been variously characterized as an estrogen and as an antiestrogen. To more completely understand the pharmacological properties of this contraceptive steroid, simultaneous responses were studied in uterine, vaginal, and hepatic tissues. Rats received 4 daily sc injections with either anordiol, clomiphene citrate (CC), or the vehicle alone (C+) starting on the first day of pseudopregnancy. Uteri were traumatized on day 4 of pseudopregnancy, and rats were sacrificed 5 days later. A pseudopregnant group without uterine trauma served as a negative control (C-). Mean uterine weights per animal and cytosolic estrogen (EcR) and progesterone (PcR) receptor activities per g of DNA were all 5- to 7-fold greater in the C+ group than in the other groups (all p < 0.05). However, anordiol and CC suppressed uterine weight without suppressing the stromal proliferative response; the DNA content of the uteri of anordiol- and CC-treated rats was similar to that of C+ rats. Vaginal tissue exhibited estrogenic responses to anordiol and CC with an increase in epithelial stratification compared to the C+ and C- groups even though no difference in levels of EcR/g of DNA were expressed 5 days after the last antiestrogen dose. Binding affinities and serum E2 and progesterone (P) concentrations were not statistically different among the groups. In conclusion, anordiol produced responses in the uterus and vagina of the pseudopregnant rat which were indistinguishable from those of CC, and, therefore, we conclude that anordiol acts on these tissues as an antiestrogen.

Media prepared with egg yolk and two buffers, TES and Tris, called TEST-yolk have been shown to have beneficial effects on the survivability, fertilizing capacity and storage potential of human spermatozoa. Egg yolk lipoproteins are the critical compounds for the beneficial effects, with a synergistic effect due to the TES-Tris buffer component. TEST-yolk media have been used in the sperm penetration assay, the hemizona assay, sperm preparation for clinical in-vitro fertilization, artificial insemination with homologous spermatozoa, cryopreservation, sperm samples with a positive antisperm antibody test, and preparation for techniques requiring capacitated spermatozoa. Few harmful consequences of TEST-yolk have been reported, although controlled trials are required to evaluate therapeutic effects in the treatment of male infertility.

Emergency contraception could reduce the number of unintended pregnancies by 1.7 million. The best approach to oral contraception is education and not limitation, but it is unlikely that there will be any increase in contraceptive availability in the near future. Routine ultrasonography in low-risk pregnancies does not appear to be cost-effective.

The purpose of the study was to assess the impact of subchronic hypercortisolemia on progesterone (P) metabolism and production and on peripheral LH levels in a nonhuman primate using a repeated measures experimental design. Osmotic pumps that released hydrocortisone phosphate (HP) at a dose of 15 mg/day were implanted sc in seven cynomolgus monkeys for two menstrual cycles. The pumps were filled with saline for the two control cycles, which either preceded (three animals) or followed (four animals) HP infusion. P metabolism, P production, and episodic secretion of LH were determined 8 +/- 1 days after the serum estradiol peak in the second control cycle and in the second cycle of HP infusion in each monkey, after iv bolus administration of 50 microCi [3H]P, followed by a 6-h blood sampling period. HP infusion elevated serum cortisol levels 1.6-fold. Serum P levels were decreased throughout the luteal phase by 58% (P < 0.01). The MCR of P and the volume of distribution at steady state of P were increased by 200% during HP infusion (both P < 0.005). The production rate of P was increased by HP treatment in five of seven monkeys. HP infusion increased the ratio of 20 alpha-[3H]dihydroprogesterone to [3H]P in serum from 0.5 to 1.0 (P < 0.05) while decreasing the fraction of [3H]P and its metabolites excreted in urine from 20% to 11% (P < 0.05). Serum LH levels, determined over a 5.25-h period in the luteal phase, were elevated by 200% during HP treatment (P < 0.05). Episodic secretion of LH during treatment was characterized by a 660% increase in the pulse amplitude (P < 0.05) and an apparent decrease in the pulse frequency. The results of this study provide evidence that moderate elevation of serum cortisol levels for two menstrual cycles in primates 1) increases the MCR of P, which may be the cause of the observed decrease in serum P levels; and 2) elevates serum LH levels by amplifying its pulse amplitude, which may result in a compensatory rise in the production rate of P.

Background: Febrile morbidity following in vitro fertilization and embryo transfer (IVF-ET) is a rare but possibly serious complication. This report describes a case of salpingitis after IVF-ET and discusses the possible reasons for febrile morbidity following this common procedure., Case: A 37-year-old woman undergoing IVF-ET for tubal factor infertility developed sudden, severe pelvic pain, fever, and leukocytosis 24 hours after ET. Laparoscopy revealed bilateral suppurative pyosalpinges with cystic, hemorrhagic ovaries. Pain, fever, and leukocytosis resolved with conservative surgery and intravenous antibiotic therapy., Conclusions: This case presents laparoscopic documentation of a rare complication of oocyte aspiration and/or ET, namely, salpingitis. Possibilities for the development of salpingitis following IVF-ET include activation of quiescent bacteria within the fallopian tubes from a previous pelvic infection, puncture of the bowel during oocyte aspiration, inoculation of the pelvis with cervicovaginal flora during oocyte aspiration, and introduction of bacteria-laden secretions or air into the fallopian tubes during ET. Although rare, the possibility of severe pelvic infection following IVF-ET warrants consideration of prophylactic antibiotic coverage.

In this nonblinded, controlled multicenter trial, postmenopausal women were randomly assigned to receive graded doses of toremifene and tamoxifen or no antiestrogen to assess dose-response levels and evaluation methodology. For standardization, transdermal estradiol (Estraderm-Ciba Geigy) was applied to all women for 38 days. The antiestrogens were added on days 29-38. For control and all treatment groups, there were no significant changes in serum chemistries or serum hormone levels, nor were there differences in adverse effects. The use of continuous estradiol precluded any meaningful assessment of the estrogenicity of tamoxifen or toremifene. As measured by vaginal superficial cytologic cell count changes, the antiestrogenic activity of toremifene doses ranging from 20 to 200 mg/day could not be distinguished from that of 20 mg/day of tamoxifen, the clinically recommended dose in North America.

Objective: To compare pregnancy rates after intrauterine insemination (IUI) versus pericervical insemination in absolute male factor infertility using each patient as her own control., Design: Ovulatory women with patent fallopian tubes without male partners were alternately inseminated with cryopreserved donor semen using either IUI or pericervical insemination techniques. A total of 81 cycles, which included up to 4 cycles per patient were performed. In this manner a comparison between the efficacy of each method could be evaluated., Setting: The donor insemination program at the Center For Assisted Reproduction at Northwestern University Medical School., Patients: Twenty-six single, healthy, unmarried women with patent fallopian tubes and < 40 years of age without male partners (absolute male factor infertility)., Main Outcome Measures: Positive quantitative serum subunit of human chorionic gonadotropin followed by the presence of an intrauterine gestational sac seen by transvaginal ultrasonography., Results: Fourteen (54%) of 26 patients conceived including two (14%) miscarriages within four insemination cycles. Seven (17.5%) patients after IUI, and 7 (17.1%) patients after pericervical insemination conceived. The pregnancy rates were similar regardless of the order of insemination method., Conclusion: These findings reveal that there is no statistical difference in the pregnancy outcome between these two methods of insemination in absolute male factor infertility.

Endometrial receptivity to the implanting blastocyst determines whether pregnancy occurs. Whether fertilization is initiated in vivo or in vitro, the receptivity of the luteal-phase endometrium results from the input of interacting hormonal, growth, and immunologic factors. Endometrial adequacy for implantation has traditionally been assessed by the endometrial biopsy. Newer methods used to study the endometrium, such as ultrasound imaging and measurement of endometrial proteins, have increased our understanding yet have demonstrated the limits of our knowledge. This review is designed to analyze the available literature for concepts and scientific facts to aid in our understanding of the complex events required in preparation of a receptive endometrium. Special attention is focused on the effect of supraphysiologic levels of steroid hormones on the endometrium in ovulation induction. The effect of both embryo quality and luteal-phase support are also reviewed.

Purpose: Our purpose was to utilize current reproductive technologies to treat an infertile female lowland gorilla., Results: Following pituitary down-regulation with a gonadotropin releasing hormone agonist and follicular stimulation with human menopausal gonadotropins, transrectal ultrasound-guided aspiration of ovarian follicles yielded nine oocytes. Following failed fertilization with both epididymal and electroejaculated sperm, zona dissection and sperm injection were performed and produced one embryo, which was cryopreserved. Immature oocytes were obtained from ovarian sections and were either cultured in vitro or cryopreserved., Conclusions: This report demonstrates that in vitro fertilization techniques, including pituitary suppression, ultrasound-guided aspiration, micromanipulation, and cryopreservation, can be used to assist reproduction in the lowland gorilla.

To determine whether ejaculates consist of various populations of sperm with varying degrees of fertilizing capacity, semen was filtered through a glass-wool column and the filtrate aliquoted sequentially into three portions. The ejaculate and its respective filtrates were evaluated for progressive motility, ability to respond to hypoosmotic swelling (HOS) test, acrosin content, ability to capacitate and acrosome react (AR), and ability to penetrate into denuded hamster oocytes (SPA). Filtrate 1 contained significantly more sperm with progressive motility, increased acrosin content, and positive HOS and SPA results than did the ejaculate. AR did not differ between the ejaculates and the respective filtrates. The data suggest that the ejaculate consists of various populations of sperm with different properties and that these populations may be separated by glass-wool filtration.

The delay in appearance of vaginal cornification associated with administration of anordiol (de-esterified anordrin) in the post-ovulatory period was confirmed. Ovarian tissue incubated in vitro for 2 h on the day which, in normal cycles, would be the day of proestrus produced negligible amounts of estradiol even in the presence of androstenedione and human menopausal gonadotropin, despite the appearance of apparently mature follicles in the ovaries. Ovaries of untreated rats produced significant amounts of estradiol when androstenedione was present. Continued incubation for 3 days resulted in significant estradiol production by ovaries of anordiol-pretreated rats in the presence of androstenedione, but less than that of ovaries of control rats. Granulosa cells of immature rats pretreated with diethylstilbestrol (DES) were unaffected by pretreatment with anordrin, whether anordrin was given before or after DES treatment. Taken together, the results indicate that anordiol inhibits development of the capacity for estrogen secretion in maturing follicles without affecting structural development, but that follicles that grow under the influence of high concentrations of estrogen (DES) are unaffected by the presence of anordrin (which is rapidly converted to anordiol in vivo). The latter result suggests that DES treatment bypasses the anordiol-sensitive step in follicular maturation.

The use of gonadotropin releasing hormone agonists (Gn-RHa) has been shown to improve the response in patients classified as "poor responders" undergoing ovarian stimulation for in vitro fertilization/embryo transfer (IVF/ET). This study sought to determine whether GnRHa therapy would benefit patients undergoing IVF/ET who had been classified as "good responders" in prior attempts. Twenty-three patients who had completed a prior IVF/ET attempt but who failed to conceive underwent ovarian stimulation using a combination of GnRHa and human menopausal gonadotropin (hMG). Each patient's prior stimulation served as her control and consisted of clomiphene citrate (CC)/hMG in 18 patients and follicle stimulating hormone (FSH) and/or hMG in 5 patients. The numbers of oocytes retrieved, oocytes fertilized, embryos cleaved, and embryos transferred were all significantly greater in cycles treated with GnRHa/hMG compared to control cycles. The clinical pregnancy rate was 39% and the ongoing pregnancy rate was 26% during the cycle when GnRHa pretreatment was utilized. These data suggest that GnRHa therapy is of benefit even to those patients previously classified as "good responders" undergoing ovarian stimulation for IVF/ET.

The incidence of abnormal endometrial histology in patients undergoing human menopausal gonadotropin/human chorionic gonadotropin (hMG/hCG) treatment during cycles of in vitro fertilization (IVF) or gamete intrafallopian transfer has been reported to be 52% to 91%. The incidence of endometrial inadequacy, as judged by a single late luteal endometrial biopsy, has not been studied in hMG/hCG non-IVF cycles. In the current study, 30 patients (30 cycles) undergoing hMG/hCG treatment were evaluated by an endometrial biopsy. The incidence of endometrial inadequacy was found to be 27%. No preovulatory predictors for endometrial inadequacy could be identified. Therefore, luteal support for patients undergoing non-IVF hMG/hCG cycles should be considered.

Most patients undergoing laparoscopic procedures experience no complications; however, a major complication rate of approximately 0.3% has been documented. Cardiomyopathy is also rare. A patient who underwent laparoscopy for oocyte retrieval during in vitro fertilization/embryo transfer developed congestive heart failure and pulmonary edema. A cardiomyopathy was diagnosed subsequently.

Ninety pregnancies conceived by infertile couples using assisted reproductive technologies and 86 pregnancies conceived by infertile couples with routine infertility treatment were analyzed to determine the outcome of and the complications experienced during the pregnancies. Pregnancies ending after 24 weeks' gestation were evaluated for the following complications: pregnancy-induced hypertension, diabetes mellitus, preterm labor, premature rupture of membranes, placenta previa, and fetal growth retardation. A matched control group of normal fertile patients admitted to the obstetric service at Vanderbilt University Medical Center was used to compare the incidence of pregnancy complications among the groups. In the group treated by assisted reproduction, 81 pregnancies were singleton and nine were multiple gestations, whereas in the routine group, 84 were singleton and two were multiple gestations. In the group treated by assisted reproduction, 29 of 90 gestations (32%) ended before 24 weeks, compared with 18 of 86 (21%) in the routine group, a nonsignificant difference. Mean birth weight and gestational age were similar among the three groups for singleton gestations. Among multiple gestations, the mean (+/- standard error of the mean [SEM]) birth weights were 2513 +/- 115, 724 +/- 57, and 2282 +/- 132 g in the group treated by assisted reproduction, the group receiving routine methods, and the control group, respectively (P less than .001 when those treated by routine methods were compared with the other two groups). The mean (+/- SEM) gestational ages were 36 +/- 1.2, 26.5 +/- 2.0, and 35.5 +/- 1.2 weeks, respectively (P less than .01 comparing those treated by routine methods and the other two groups).(ABSTRACT TRUNCATED AT 250 WORDS)

A retrospective analysis of patients evaluated and treated for infertility was performed. Luteal phase inadequacy was diagnosed when the late luteal endometrial biopsy pattern was greater than 2 days out of phase in two cycles; in patients treated with clomiphene citrate therapy was changed if one biopsy was out of phase. One hundred ninety-seven patients underwent 242 biopsies. Among 137 women no treated with clomiphene citrate, 24 (17.5%) had out-of-phase biopsy specimens; 7 of 24 (29.2%) repeat biopsies were out of phase, with luteal phase inadequacy in 7 of 137 (5.1%) women. The probability of an out-of-phase biopsy occurring by chance alone was 4.2 of 137 or 3.1%. No woman was diagnosed to have luteal phase inadequacy as the single infertility factor. Fifty-three pregnancies (41%) occurred in 130 women without luteal phase inadequacy and in 2 of 7 (28.6%) diagnosed to have luteal phase inadequacy with other infertility factors. In clomiphene citrate-treated patients, pregnancy occurred in 15 of 26 (57.7%) with corrected luteal phase inadequacy and in 21 of 34 (61.8%) without luteal phase inadequacy. In this population the diagnosis of luteal phase inadequacy was not made more frequently than by chance alone. Moreover, fecundity in patients with treated luteal phase inadequacy is comparable to that in patients without this diagnosis.

The prevalence of menstrual dysfunction is greater among athletes than in the general population. Many factors undergo change during the course of an athletic training program and any or all of these may contribute to disturbances in menstrual cyclicity. All athletes with oligomenorrhea, amenorrhea, or menarcheal delay require thorough evaluation to rule out serious pathological conditions, since the diagnosis of exercise-associated menstrual dysfunction can be made only by excluding other etiologic factors. Most athletes who have these problems should be treated to prevent undesirable sequelae.

Hyperandrogenic states in women may alter hypothalamic pituitary response. The pituitary function of a 64-year-old postmenopausal woman with a testosterone-secreting (T-secreting) ovarian neoplasm was assessed with a combined infusion of ovine corticotropin releasing hormone, 1 microgram/kg; GnRH, 100 micrograms; human growth hormone releasing hormone, 1 microgram/kg; and TRH, 200 micrograms preoperatively when T and estradiol (E2) were elevated, six weeks postoperatively when T and E2 were low and 16 months postoperatively while the patient was on micronized E2 (low T, high E2). The principal findings were a reduction in luteinizing hormone response by both T and E2, no effect of either T or E2 on follicle stimulating hormone and greater growth hormone and TSH responses in an estrogenic milieu.

We have studied a group of 19 patients presenting with proximal tubal occlusion. Seventy-three percent (22/30) of tubes attempted were successfully cannulated. Sixty-two percent (5/8) of tubes remained patent in limited follow-up at 3 to 6 months. We conclude that selective fallopian tube cannulation may provide an alternative to microsurgical tubal anastomosis in selected patients.

Endometrial biopsies for evaluation of the luteal phase should be taken within 2 days of the onset of menses. When these guidelines are followed and patients present at least 12 days after the thermogenic shift on BBT, the ICON pregnancy test is extremely rapid, sensitive, specific, and has predictive values close to 100%. If a biopsy is undertaken before this time there may be an increased risk of false negative results (i.e., a decreased sensitivity). The improved technology in urine pregnancy tests has now made it feasible to obtain accurate urine pregnancy tests before endometrial instrumentation with an increased level of confidence. It is recommended that this technology be used in the management of patients undergoing endometrial biopsies in the late luteal phase.

A retrospective review of 62 patients with primary amenorrhea indicates that thoughtful clinical evaluation combined with dynamic hypothalamic-pituitary testing can usually determine the etiology and prognosis. A careful history, consideration of chronologic age/bone age/height relationships, and assay of serum gonadotropins distinguished all patients with medical diseases, ovarian failure, hypogonadotropic hypogonadism, and polycystic ovaries. Luteinizing hormone-releasing hormone (LH-RH) stimulation, sometimes combined with clomiphene therapy and estrogen provocation tests, assisted with prognostic and pathophysiologic evaluation, although patient management rarely changed. An age-inappropriate LH-RH test result was helpful in identifying patients with abnormal maturational patterns.

Two hundred twenty-six patients received artificial insemination with fresh donor semen (AID) using the cervical cap technique; 52 patients underwent the procedure for 2 conceptions. Using life-table analysis to adjust for uneven patient follow-up, the cumulative pregnancy rate was 62.5% after 6 months of AID, and 82.4% after 10 months. Moreover, using a mathematical model of cumulative pregnancy following AID, the estimated cure rate was not significantly different from 100%, and the estimated monthly probability of pregnancy among those cured was 15.5%. Age was found to be inversely related to pregnancy success, while parity had no effect. For those who continued to undergo AID beyond 6 months, the monthly probability of pregnancy did not decline. Patients can be advised that their chance of conception with AID should approach that of normal fertile couples.

In mammals, insulin stimulates granulosa cell aromatase activity and steroid production and is a regulating factor of oocyte maturation. To assess the role of insulin in human follicular and oocyte maturation, human follicular fluid was obtained 32-36 h after hCG administration at the time of oocyte recovery for in vitro fertilization. Follicular fluid insulin levels, measured by RIA, ranged from undetectable (less than 2 microU/ml) to 65.4 microU/ml. In women treated with human menopausal gonadotropin (n = 21), clomiphene citrate (n = 4), and human menopausal gonadotropin/clomiphene citrate (n = 14), follicular fluid insulin concentrations were 18.0 +/- 4.3 (+/- SE), 10.2 +/- 4.2, and 12.0 +/- 3.8 microU/ml, respectively (P = NS). Similarly, there was no significant difference in follicular fluid insulin concentrations in follicles with mature (n = 33) or immature (n = 6) oocytes (13.3 +/- 2.7 vs. 24.7 +/- 9.5 microU/ml) or in oocytes which eventually did (n = 35) or did not (n = 4) fertilize (16.4 +/- 3.0 vs. 3.2 +/- 0.8 microU/ml). Follicular fluid insulin levels (n = 30) correlated positively with follicular fluid progesterone levels (P less than 0.05), but not with follicular fluid estradiol or androstenedione levels or the estradiol to androstenedione ratio. The relationship of follicular fluid insulin and progesterone levels suggests that, as in other mammals, follicular fluid insulin may have a physiological role in follicular maturation.

The experience of the gynecologic endocrinology and infertility clinic at The Johns Hopkins Hospital has been subjected to a nonconcurrent prospective analysis in an attempt to evaluate the gestational fate of clomiphene-related conceptions (study series, n = 86). This latter series was contrasted with a series of pregnancies following bilateral ovarian wedge resection (BOWR) (n = 51) in a comparative analysis of gestational outcome event rates. Post-therapy follow-up was available for varying time spans of up to 15 years. A 12.8% twinning rate constituted the single most important complication of clomiphene therapy, resulting in measurable increments in perinatal morbidity and mortality rates. The observation of a 26.5% spontaneous abortion rate would seem to suggest that clomiphene-related conceptions are at little or more risk for spontaneous abortion than would have been expected from the infertile population under discussion. A 3.1% incidence of post-clomiphene birth defects was not increased as compared with commonly quoted rates for the population at large. The corresponding incidence rates of twinning, spontaneous abortion, and birth defects for the BOWR series were 0%, 21.6%, and 0%, respectively.

In addition to symptomatic or endocrine treatment, management of dysmenorrhea requires an understanding of the constitutional and psychogenic factors that play a role in the symptoms associated with the ovulatory cycle.

To determine whether the rate of the exponential rise of estradiol (RER-E2) may be useful in monitoring gonadotropin-induced cycles and have prognostic value with respect to pregnancy, the RER-E2 was evaluated in 70 ovulatory cycles of 25 women. Semilogarithmic plots of E2 concentrations (picograms per milliliter) versus time (days) were linear, with slopes (RER-E2) ranging from 0.18 to 0.74. The mean RER-E2 in the 14 cycles of conception (0.49 +/- 0.03; +/- standard error) was not significantly different from the mean (0.47 +/- 0.02) in 56 cycles in which pregnancy did not occur. The mean of the RER-E2 of three twin pregnancies (P less than 0.02) and of three pregnancy losses (P less than 0.01) were significantly higher than the mean of nine singleton pregnancies. There was a lower pregnancy rate at the lower range of RER-E2 and a higher frequency of twin pregnancies and pregnancy losses at the upper range, but these trends were not statistically significant. By a graphic method, subsequent E2 values were predicted in 25 of 28 cycles within the 95% confidence limits and a clinically acceptable range of actual E2 values. The semilogarithmic plots appear to be useful adjuncts in the monitoring of gonadotropin-induced cycles. Although the data suggest that the RER-E2 may have prognostic value, further study is needed to confirm these observations.