The effect of clomiphene citrate on early embryonic development, endometrium and implantation

The association between endometrial thickness and pregnancy outcome in gonadotropin-stimulated intrauterine insemination cycles

BACKGROUND

Intrauterine insemination (IUI) is the first-line treatment for non-tubal infertility. Injectable gonadotropins are often chosen as adjunctive stimulation to promote the growth of ovarian follicles in IUI cycles. The growing follicles produce estrogen, which induces endometrial proliferation and increased endometrial stripe thickness (EST). The association between EST and pregnancy outcome in gonadotropin stimulated IUI is not well studied. The objective of this study is to determine if EST can predict pregnancy outcome in gonadotropin-stimulated IUI cycles.

METHODS

A retrospective review was conducted of all exclusively gonadotropin-stimulated IUI cycles performed between 2012 and 2015 at an academic fertility clinic. Mean endometrial thickness was compared in positive versus negative cycles using Student T-test. Peak EST values were then divided into four groups of < 7 mm, 7.0-10.4 mm, 10.5-13.9 mm, and ≥ 14 mm. Multiple logistic regression analysis adjusted for potential confounders was conducted to assess the impact of peak EST on cycle outcome.

RESULTS

Our sample consisted of 1065 IUI cycles representing 548 patients with a 16.9% clinical pregnancy rate and 20.5% conception rate. No significant differences in mean peak EST were observed between cycles that achieved clinical pregnancy or conception and those that did not. Division of peak EST into four groups showed a non-linear relationship between peak EST and cycle outcome, with highest rates of positive outcomes between 10.5-13.9 mm. The odds of clinical pregnancy and conception increased by 38 and 44% respectively with each subsequent peak EST category up to 10.5-13.9 mm, following which they declined.

CONCLUSION

This is the largest study to date evaluating the effect of peak EST on gonadotropin-stimulated IUI cycles exclusively. The lack of significant difference in peak EST between positive and negative outcomes cycles may be due to the non-linear relationship between cycle outcomes and peak EST. Peak EST in the range of 10.5-13.9 mm was associated with significantly higher conception rates and a trend towards higher clinical pregnancy rates. This non-linearity is likely one of the reasons that EST in isolation was found to be a poor predictor of IUI outcomes, and therefore is not appropriate to be used as the sole indicator for cycle cancellation.

Intrauterine insemination in natural cycle may give better results in older women

BACKGROUND

Controlled ovarian hyper-stimulation (COH) in combination with intrauterine insemination (IUI) has been shown to result in significantly higher pregnancy rates compared to un-stimulated (natural cycle) IUI. This may however not be true in all ages.

METHODS

We performed a retrospective cohort study and analysed data collected prospectively on 1759 IUI cycles in couples with unexplained infertility. The results were analysed to show the outcome of IUI with COH, and IUI in natural cycle (unstimulated), in younger women compared to their older counterparts.

RESULTS

In women age 37 and younger, COH resulted in a significantly higher pregnancy rate (13.0% vs 6.5%) and live-birth rate (10.7% vs 5.2%) compared to natural cycle IUI (p = 0.025, p = 0.045 respectively). However for older women age >37 years, natural cycle (unstimulated) IUI, resulted in a significantly higher pregnancy rate (12.0% vs 8.5%) live-birth rate (7.5%vs 3.5%) than IUI with COH ((p = 0.0037). This difference is even more significant when COH was performed with clomiphene citrate (7.5% vs 2.1%) (p = 0.0017).

CONCLUSION

COH was associated with a lower live birth rate in older women, irrespective of the agent used, and it seems to be worse when the anti-oestrogenic drug clomiphene citrate was used for COH. Older women may benefit more from natural cycle (unstimulated) IUI. A randomised controlled trial is required to confirm this observation.

High frequency of iatrogenic monozygotic twins with administration of clomiphene citrate and a change in chorionicity

The data of the population-based, prospective survey of multiple births in East Flanders, Belgium, show that a greater proportion of monozygotic twins is observed with clomiphene citrate as sole treatment compared with other ovulatory drugs. Among iatrogenic monozygotic twins, the ratio of monochorionic versus dichorionic pairs is higher compared with spontaneous twins.

Endometrial receptivity: Clinical assessment in relation to fertility, infertility, and antifertility

Fertility in humans and other mammalian species depends absolutely on synchronous events that render the developing blastocyst and the receiving uterus competent for implantation. Endometrial receptivity is defined as the period during which the endometrial epithelium acquires functional, but transient, ovarian steroid-dependent status supportive to blastocyst acceptance and implantation. Once inside the uterus, the blastocyst is surrounded by an intact luminal epithelium, which is considered to act as barrier to its attachment, except for this short period of high endometrial receptivity to blastocyst signal(s). Its transport and permeability properties, in conjunction with cellular action of the endometrium and the embryo, have been suggested to influence creation and maintenance of informational and nutritional status of uterine luminal milieu. This period, also termed as the 'window of implantation,' is limited to days 20-24 of menstrual cycle in humans. However, establishment of endometrial receptivity is still a biological mystery that remains unsolved despite marked advances in our understanding of endometrial physiology following extensive research associated with its development and function. This review deals with various structural, biochemical, and molecular events in the endometrium coordinated within the implantation window that constitute essential elements in the repertoire that signifies endometrial receptivity and is aimed to achieve a better understanding of its relationship to fertility, infertility, and for the development of targeted antifertility agents for human use and welfare.

Endometrial thickness cannot predict ongoing pregnancy achievement in cycles stimulated with clomiphene citrate for intrauterine insemination

To date, limited data exist concerning the relation between endometrial thickness on the day of human chorionic gonadotrohin (HCG) administration and ongoing pregnancy achievement in cycles stimulated with clomiphene citrate for intrauterine insemination (IUI). In a prospective study, 168 couples were stimulated with clomiphene citrate from day 3 to day 7 of the cycle and endometrial thickness was assessed by ultrasound three times on the day of ovulation triggering. Ovulation was induced with HCG as soon as >/=1 follicle of >/=17 mm was present at ultrasound independently of endometrial thickness. IUI was performed 36 h after HCG administration. The main outcome measure was ongoing pregnancy. No difference was observed in endometrial thickness between patients who did or did not achieve an ongoing pregnancy (7.6 +/- 0.3 versus 7.6 +/- 0.2 respectively; P = 0.7). No discriminative ability of endometrial thickness on the achievement of ongoing pregnancy could be shown by receiver operating characteristic (ROC) curve analysis (area under the ROC curve 0.51, 95% CI: 0.44-0.59). In conclusion, endometrial thickness cannot predict ongoing pregnancy achievement in IUI cycles stimulated with clomiphene citrate.

Effects of initiation day of clomiphene citrate on the endometrium of women with regular menstrual cycles

OBJECTIVE

To investigate the effects of initiation time of clomiphene citrate (CC) on the endometrium of women with regular menstrual cycles.

DESIGN

Randomized, double-blind, cross-over study.

SETTING

Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.

PATIENT(S)

Thirty-three healthy female volunteers with regular menstrual cycles.

INTERVENTION(S)

The volunteers were randomized to receive either 100 mg of CC on days 1-5 and placebo on days 5-9 (study group) or placebo on days 1-5 and CC on days 5-9 (control group). After a wash-out period of 1 month of CC treatment, the medication was switched in each group. Ultrasonography was performed daily after day 10 of the cycle to detect ovulation. Ultrasonography for endometrial appearance and thickness, endometrial sampling, and blood samples obtained for determination of E(2) and P levels were performed 7 days after ovulation in both groups.

MAIN OUTCOME MEASURE(S)

Morphometric analysis, histologic dating, and ultrasonographic appearance and thickness of the endometrium.

RESULT(S)

Morphometric parameters, histologic dating, and ultrasonographic appearance and thickness of the endometrium were similar in both groups.

CONCLUSION(S)

Starting CC on either day 1 or day 5 of the menstrual cycle did not have any differential effects on the endometrium of women with regular menstrual cycles, particularly regarding the morphometric analysis, histologic dating, or ultrasonographic appearance.

Hormone patterns after induction of ovulation with clomiphene citrate: an age-related phenomenon

Since the introduction of clomiphene citrate (CC), more than three decades ago, a discrepancy has been observed between ovulation and pregnancy rates for which as yet no explanation exists. To investigate if ovulation disorders or abnormal hormonal patterns occur more often in CC-stimulated seemingly ovulatory cycles, we performed hormonal and sonographic monitoring in first cycles of oligo- or amenorrheic patients who were stimulated with 50 mg CC, and compared the hormonal patterns to those in natural cycles of age-matched proven fertile women. Twenty-four first CC cycles were monitored. Twelve cycles appeared to be ovulatory, eleven showed no follicle development and one cycle exhibited the luteinized unruptured follicle (LUF) phenomenon. Ten ovulatory cycles were compared with 27 unstimulated control cycles. In four cycles stimulated by CC, a temporary decline in estradiol levels was apparent. In these cycles, estradiol reached a higher level on cycle day (CD) 7 or 8 compared to cycles without a decline. Such an estradiol decline was seen in only one control cycle. Furthermore, the estradiol levels on CD 7 or 8 appeared to be age-related. We conclude that the estradiol decline in CC-stimulated ovulatory cycles may be a consequence of a sharp rise after CC stimulation, and such a rise may be age-related and coincide with a diminished follicle quality. If this phenomenon is associated with a suboptimal cycle, and so contributes to the suboptimal pregnancy rates after ovulation-induction treatment with clomiphene citrate, is still unknown.

A flexible protocol for artificial preparation of the endometrium without prior gonadotropin-releasing hormone agonist suppression in women with functioning ovaries undergoing frozen-thawed embryo transfer cycles

OBJECTIVE

To present our experience with a flexible and convenient protocol for artificial endometrial preparation without prior GnRH agonist suppression in patients with functioning ovaries undergoing frozen ET.

DESIGN

Case series.

SETTING

An IVF unit in a university hospital.

PATIENT(S)

All patients who underwent IVF with embryo cryopreservation from December 1997 to June 1998 and requested transfer of their frozen-thawed embryos.

INTERVENTION(S)

Controlled endometrial preparation for ET entailed the use of a fixed dose of 6 mg/d of micronized E2 started on day 1 of the cycle, followed by concomitant administration of micronized P placed in the vagina.

MAIN OUTCOME MEASURE(S)

Hormonal and endometrial profiles throughout the cycle, pregnancy rate per ET, implantation rate, and pregnancy outcome.

RESULT(S)

Of 185 treatment cycles in 140 patients, 8 cycles (4.3%) were canceled. In another 2 cycles, no embryos were suitable for transfer. For the remaining 175 ET cycles, the calculated pregnancy rate and implantation rate were 21.7% and 9%, respectively. The proliferative phase could be extended up to 20 days but was a mean (+/-SD) of 15+/-1.9 days.

CONCLUSION(S)

For patients with functioning ovaries, controlled endometrial preparation for the transfer of frozen-thawed embryos can be done successfully by using oral E2 from day 1 of the cycle followed by P preparation. Prior suppression with GnRH agonist is not necessary.

Effects of clomiphene citrate on the endometrial thickness and echogenic pattern of the endometrium

OBJECTIVE

To study the effects of clomiphene citrate (CC) on the endometrium by ultrasound and to reveal the echogenic difference between the control cycle and the CC cycle.

DESIGN

Retrospective study of patients before and during a CC treatment.

SETTING

Department of Obstetrics and Gynecology, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan.

PATIENT(S)

Seventy-nine infertile women who had a spontaneous ovulation and a normal luteal function.

INTERVENTION(S)

Patients received 50 mg/d CC between days 5 and 9 of the menstrual cycle.

MAIN OUTCOME MEASURE(S)

Endometrial thickness, echogenic pattern of the endometrium, serum E2 content, and E2 and P receptor contents in the endometrium.

RESULT(S)

Endometrial thickness was significantly thinner during the CC cycle (7.6 +/- 1.4 mm, mean +/- SD, n = 79) than during the control cycle (8.5 +/- 1.7 mm, n = 79) on late proliferative days, but there was no significant difference on midsecretory days (10.8 +/- 2.2 mm during the CC cycle, n = 79; 11.2 +/- 2.2 mm during the control cycle, n = 79). The echogenic patterns, however, were different between the two cycles on midsecretory days. Moreover, the incidence in which patients showed a grade 3 endometrium on midsecretory days was significantly higher during the conceived CC cycle compared with the not-conceived CC cycle. Serum E2 levels were significantly higher, but E2 receptor contents in the endometrium were significantly lower during the CC cycle (67 +/- 46 fmol/mg, n = 13) compared with the control cycle (123 +/- 89 fmol/mg, n = 15) on late proliferative days.

CONCLUSION(S)

Clomiphene citrate affected the echogenic pattern of the endometrium, and most of the endometrium showed a grade 3 pattern on midsecretory days during the conceived CC cycle. Under the CC treatment, the comfortable endometrium for embryos might be different from the control cycle.

Early pregnancy factor (EPF) as a marker for detecting subclinical embryonic loss in clomiphene citrate-treated women

PROBLEM

A discrepancy exists between the apparently normal ovulation and the pregnancy rates in women treated with clomiphene citrate (CC). Our previous studies have indicated that immuno-suppressive "early pregnancy factor" (EPF) is a novel marker to detect subclinical embryonic loss in infertile women.

METHOD

In the present study EPF was used as a marker to detect subclinical embryonic loss in women treated with CC with/without gonadotropins. In some of the women treated with CC, conception was assisted by artificial insemination with husband's semen (AIH).

RESULTS

Our results have indicated that fertilization occurred (EPF + ve) in 47.7% (52/109) of women treated with CC with/without gonadotropins; 13.46% (7/52) retained the fetus and continued pregnancy till full term, whereas 78.9% (41/52) did not retain the fetuses. In the group where after stimulation, conception was assisted by AIH, fertilization was observed in 38.24% (26/68), retention in 11.54% (3/26) but subclinical embryonic loss was observed in 80.8% (21/26) cases.

CONCLUSION

Thus, our results have indicated that subclinical embryonic loss may account for some of the discrepancy observed between the apparently normal ovulation and the pregnancy rates in women treated with clomiphene citrate.

Incidence of autoimmune antibodies in failed embryo transfer cycles

PROBLEM

The presence of antiphospholipid antibodies lupus anticoagulant (LAC), anticardiolipin antibody (ACA) as well as antinuclear antibody (ANA) has been associated with early spontaneous pregnancy loss and adverse pregnancy outcome. The purpose of this study was to investigate the possible role of autoimmune antibodies (LAC, ACA, and ANA) as a cause of implantation failure following embryo transfer (ET) after in vitro fertilization (IVF).

METHOD

Three groups were studied: Group I, 56 patients who failed to conceive following ET; group II, 14 patients who have conceived following IVF-ET and delivered or are carrying an uncomplicated ongoing pregnancy; and group III, 69 patients who were new candidates for IVF-ET.

RESULTS

Eighteen out of 56 (32.1%) of patients who failed to conceive following previous IVF-ET cycle (group I) tested positive for one or more of the autoimmune antibodies. None of the 14 patients of group II tested positive for autoimmune antibodies (P < .02). Seven out of the 69 patients (10%) of group III were found positive to one or more of the autoimmune factor. This rate is significantly lower than the rate of positive autoimmune antibodies detected in group I (P < .003). Fifteen patients of the 18 who tested positive for autoimmune antibodies and who had previously failed to conceive following ET underwent a subsequent IVF-ET cycle while being treated with prednisone and aspirin. Seven out of the 15 (46.6%) conceived and were able to sustain a clinical ongoing pregnancy.

CONCLUSIONS

Patients receiving ET are carrying viable embryos within the intrauterine environment. Therefore, in this unique group of patients, failure to demonstrate a positive pregnancy test represents an implantation failure or a very early postimplantation loss. The results of this study suggest that periimplantation events may be affected by autoimmune antibodies. Very early miscarriage or implantation failure may be related to the same pathophysiological mechanism that causes recurrent miscarriages and is diagnosed incorrectly as infertility.

Growth factors and growth modulators in human uterine endometrium: their potential relevance to reproductive medicine

OBJECTIVE

To provide an up-to-date, comprehensive review on the presence and regulation of growth factors (GFs), GF receptors, and GF regulatory proteins in human endometrium in an effort to understand the potential roles of these proteins in endometrial cell mitosis and differentiation and in endometrial-trophoblast interactions.

DESIGN

Relevant studies were identified through a computerized bibliographic search (MEDLINE; BRS Information Technologies, a division of Maxwell Online, Inc., McLean, VA) and through manual scanning of recent relevant journals.

RESULTS

Several GFs, their receptors, and regulatory proteins have been identified in endometrium, and cellular localization and steroid-dependence of these proteins as well as action of several growth modulators on endometrial cell function have been studied. Epidermal growth factor, transforming growth factor (TGF)-alpha, platelet-derived growth factor, insulin-like growth factors (IGFs) and their binding proteins, fibroblast growth factor (FGF), TGF-beta, colony-stimulating factor (CSF)-1, and interferon-gamma regulate mitosis of endometrial cellular components in vitro. Endothelin-1 may participate in vasoconstriction and FGF may participate in angiogenesis in this tissue in vivo. Interleukins-1 and -6 are believed to be involved in endometrial T-cell activation, and TGF-beta, CSF-1, the interleukins, and the IGFs likely mediate endometrial-trophoblast interactions. The role of tumor necrosis factor in endometrium remains uncertain.

CONCLUSIONS

Current evidence supports the thesis that GFs play a central role in cyclic mitosis and differentiation of endometrial cellular components, recruitment of macrophages in decidualizing endometrium, endometrial-trophoblast interactions, early pregnancy maintenance, tissue shedding in the absence of implantation, and endometrial functionalis regeneration.

Ovulation induction in polycystic ovary syndrome: a review of conservative and new treatment modalities

Polycystic ovary syndrome (PCOS) is a complex disorder with heterogeneous clinical and endocrine features. Chronic anovulation and infertility are common and affect about 75% of the patients. Ovulation induction in PCOS patients is a challenge for the physicians who treat these patients. Several different treatment modalities have been proposed to induce ovulation in PCOS, each of which deals with a different clinical or endocrine disorder which is present in these patients. This review presents traditional and new methods for ovulation induction in PCOS patients, the theoretical background, the pros and cons for each treatment and success rate.

Clomiphene citrate affects cervical mucus and endometrial morphology independently of the changes in plasma hormonal levels induced by multiple follicular recruitment

OBJECTIVE

To analyze the effects of clomiphene citrate (CC) on cervical mucus (CM) and endometrial morphology independently of hormonal changes encountered when CC is administered for ovulation induction.

DESIGN

Volunteers whose ovarian functions were temporarily suppressed (n = 18) by a long-acting GnRH agonist and 6 women of similar age suffering from premature ovarian failure (POF) received E2 and P. Half of the women also received CC (50 mg/d, days 2 to 6).

SETTING

Tertiary University Institution, Hôpital A. Béclère.

PATIENTS, PARTICIPANTS

Eighteen volunteers suffering from infertility not related to a uterine cause and 6 women of similar age suffering from POF.

MAIN OUTCOME MEASURE

Plasma gonadotropins, E2, and P were measured at baseline to confirm that the ovaries were inactive and twice weekly during physiological E2 and P replacement. Cervical mucus was analyzed on day 14 and scored from 0 to 15. Endometrial biopsies were obtained on replacement days 20 and 24 for conventional histology and immunocytochemistry analysis of estrogen receptors and progesterone receptors (PR). Premature ovarian failure women whose results have been previously published served as controls for day 20 biopsies.

RESULTS

Cervical mucus scored lower in women who received CC (5.5 +/- 3.2) than in controls (13.6 +/- 4.7, mean +/- SEM). On day 20, endometrial findings were similar in women treated with CC and in controls. On day 24, specimens showed a significant delay in endometrial maturation in women treated with CC. On day 24, only staining for PR selectively persisted in endometrial stroma, and no difference was observed between women who received CC and controls.

CONCLUSION

Our results indicate that CC significantly alters CM quality and late luteal phase endometrial morphology despite physiological levels of plasma E2 and P. Hence, clinicians should monitor E2 levels when using CC, and caution should be exerted when supraphysiological levels of E2 are not present to counterbalance the effects of CC on the CM and the endometrium.

Preovulatory administration of clomiphene citrate to mice causes fetal growth retardation and neural tube defects (exencephaly) by an indirect maternal effect

Clomiphene citrate was administered to female mice at different doses and different times prior to ovulation, in the preimplantation period after ovulation, and after implantation. Pregnancy outcome was determined on day 15 of gestation, when the number of implantations and resorptions were calculated relative to the number of ovulations, and fetuses were assessed for size and stage of development and morphological abnormalities. Preovulatory administration of clomiphene citrate caused decreased implantation rates and growth retardation of surviving fetuses, the degree of the effect being dependent on the dose and the time of drug injection relative to ovulation. The implantation rate was lowest, and the degree of fetal growth retardation highest, when clomiphene citrate was administered immediately before ovulation. An increased incidence of exencephaly was found in the fetuses of females injected with clomiphene citrate prior to ovulation. Transfer of blastocysts from treated mice to untreated fosters showed the effect of clomiphene citrate on implantation and fetal growth to be predominantly mediated through the female reproductive tract, rather than a direct effect on the embryo itself. Administration of clomiphene citrate in the preimplantational period resulted in complete inhibition of implantation, while the only effect when administration was after implantation was a slight reduction in fetal weight. These results indicate that preovulatory clomiphene citrate impairs uterine function, which has an indirect effect on the growth and development of the postimplantation embryo.

A prospective, randomised, cross-over study comparing the effects of clomiphene citrate and cyclofenil on endometrial morphology in the luteal phase of normal, fertile women

OBJECTIVE

To examine the effect of two anti-oestrogens, clomiphene citrate and cyclofenil, on endometrial morphology in the luteal phase.

DESIGN

A prospective, randomised, cross-over study.

SETTING

Jessop Hospital for Women, Sheffield, UK.

SUBJECTS

10 women who were previously fertile and regularly cycling.

INTERVENTION

The administration of clomiphene citrate or cyclofenil in the treatment cycles. A LH timed endometrial biopsy was taken on day LH + 6.

MAIN OUTCOME MEASURES

Histological dating and morphometric analysis of the endometrial sample.

RESULTS

Only one out of 10 subjects had abnormal endometrium. There was no difference in the results between cycles treated with clomiphene citrate and cyclofenil.

CONCLUSIONS

Clomiphene citrate or cyclofenil does not have a major adverse effect on endometrial morphology in the luteal phase of normal fertile subjects. The possible adverse effects of anti-oestrogens on endometrium may have been previously overestimated.

Pregnane derivatives as pregnancy interceptive agents: efficacy determination on growing trophoblasts (in vitro) and in pregnant hamsters (in vivo)

An in vitro test system was standardized to study potentiality of five hormonally inert pregnane derivatives on growing trophoblasts isolated from ectoplacental cone (EPC) of day 8 hamster embryo. Cells were incubated with different concentrations of respective compounds in surface droplets. The response was determined by analyzing the sequence of changes in cell morphology like attachment, growth, proliferation, differentiation and/or degeneration within 24 or 48 h following seeding. The in vivo efficacy of these compounds was determined in hamster during peri- and immediate post-implantation periods (days 3-8 post coitum). Two compounds 88/583 and 88/585 were found to inhibit not only growth and proliferation of the cells but caused total degeneration within 24 h. The same compounds induced partial to complete resorption of the foetuses in treated animals. Whereas, the other three compounds 88/506, 88/594 and 89/43 that showed lack of comparable potentiality in vitro were found to be equally ineffective in vivo. The results indicate a positive correlationship between in vitro and in vivo activity.

Therapeutic maturation of endometrium in in vitro fertilization and embryo transfer

OBJECTIVE

To provide an up-to-date review of studies that have examined the relative role of endometrial development in in vitro fertilization (IVF) and embryo transfer (ET) treatment in relation to the treatment outcome.

DATA IDENTIFICATION

The most important published studies and personal communications related to this topic have been identified through a computerized bibliographical search (MEDLINE).

STUDY SELECTION

Studies that have evaluated the endometrial maturation in IVF and ET treatment with respect to different treatment protocols of ovarian stimulation. Clinical trials exploring the efficacy of various combinations of hormonal supplementation that aim to improve the endometrial environment and treatment outcome. Publications and personal communications reporting a variety of treatment protocols and drugs utilized for the creation of artificial endometrial cycles in IVF treatment employing donated eggs.

RESULTS

Ovarian stimulation frequently adversely affects the process of endometrial maturation. Various kinds of hormonal supplementation, used in clomiphene citrate- and/or human menopausal gonadotropin (hMG)-stimulated cycles have not improved treatment outcome. Human chorionic gonadotropin or natural progesterone (P) supplementation administered after controlled ovarian stimulation with gonadotropin-releasing hormone and hMG effectively corrected the luteal phase defect and resulted in an improved conception rate. The endometrium of agonadal women is highly conducive to hormonal manipulation. All estrogen preparations used effectively promoted endometrial growth and proliferation. Natural P is superior to synthetic progestins for induction of receptive secretory endometrium.

CONCLUSION

The development of adequately receptive endometrium is a major factor determining the outcome of IVF and ET treatment.

The effect of ethinyl estradiol on endometrial thickness and uterine volume during ovulation induction by clomiphene citrate

OBJECTIVE

To assess the deleterious effect of clomiphene citrate (CC) on the development of the endometrium and its improvement by the addition of ethinyl estradiol (E2). PARTICIPATING PATIENTS: Infertility-treated patients, monitored for induction of ovulation or timing of insemination (control group).

DESIGN

We studied four groups of women during an ovulatory cycle with various treatment schedules. Group 1: untreated patients; group 2: patients treated by CC; group 3: patients treated by CC + ethinyl E2; group 4: patients treated by human menopausal gonadotropin. Follow-up of the patients was done by vaginal ultrasonography and measurements of blood E2.

RESULTS

In the group treated by CC, both endometrial thickness and uterine volume growth during the follicular phase were lower as compared with untreated controls and menotropin-treated patients. The addition of ethinyl E2 to these patients reversed this deleterious effect of CC without interfering with ovulation.

CONCLUSION

Ethinyl E2 may reverse the deleterious effect of CC on endometrial development during the follicular phase.

Menotropins as a possible risk factor for premature deliveries in triplet pregnancies

This study was undertaken in order to evaluate pregnancy outcome in three groups of triplet conceptions. Of 36 delivered triplet gestations, seven were spontaneous, 12 achieved using clomiphene citrate and 17 induced by menotropins. The mean gestational age (weeks) at delivery was 36.5 +/- 1.0 SD, for spontaneous and clomiphene citrate pregnancies it was 35.9 +/- 1.9 SD which differed significantly from that in pregnancies induced by menotropins which was 32.9 +/- 3.7 SD. Similarly, triplets born following menotropin treatment had a significantly lower gestational weight (g) of 1656 +/- 516 SD vs. 2015 +/- 198 SD and 2176 +/- 315 SD for spontaneous and clomiphene citrate gestations, respectively. It is concluded that triplets following menotropins are at an increased risk for premature delivery and low birth weight.

Are factors that influence oocyte fertilization also predictive? An assessment of 148 cycles of in vitro fertilization without gonadotropin stimulation

Fertilization characteristics of 152 consecutively obtained oocytes in an in vitro fertilization (IVF) program employing only natural and clomiphene citrate-induced cycles were retrospectively analyzed. Fertilization occurred significantly more often (1) in women with tubal infertility, (2) in spontaneous cycles, and (3) in cases of secondary infertility. Grade I sperm motility from the original semen sample and the duration of infertility were also significant influencing factors. A similar sperm correlate was not identified on samples after sperm migration. Preovulatory follicular fluid steroids, progesterone (P), estradiol (E2), E2:P ratio, and luteinizing hormone (LH), as well as baseline plasma LH and the magnitude of the LH surge did not correlate with fertilization. However, when the identified factors were used to predict fertilization (discriminant analysis), only 58.3% of oocytes were correctly classified. This data supports the concept of performing IVF as a test in its own right.

In vitro effects of clomiphene citrate on human endometrium

Since cis-clomiphene citrate (CC) used for ovulation induction may affect embryo implantation during in vitro fertilization, direct effects of the drug on human endometrium were tested. Estrogenic and antiestrogenic effects were evaluated in vitro by measuring changes in prostaglandin (PG) output provoked by estradiol (E2), CC, and mixtures of E2 and CC; progestagenic effects were tested with E2 17 beta-dehydrogenase activity and glycogen accumulation as end points. In secretary endometrium, 10(-6)M CC about doubled the basal output of PGF2 alpha and PGE2; 10(-8)M E2 increased the production of these PGs 3-fold and 1.8-fold, respectively. The effects of E2 at this concentration were not diminished by the addition of CC, even at 100-fold molar excess, under conditions in which 10(-7)M progesterone or 10(-6)M 4-hydroxytamoxifen suppressed completely the action of the natural estrogen. In proliferative endometrium, 10(-8)M and 10(-6)M CC had no consistent effect on E2 17 beta-dehydrogenase activity or glycogen accumulation. These results demonstrate that, under in vitro conditions, CC can exert direct estrogenic effects on the endometrium but does not act as an antiestrogen or a progestagen.

In vitro fertilization: the degree of endometrial insufficiency varies with the type of ovarian stimulation

Fifty-eight patients in an in vitro fertilization program who did not have embryo transfers had endometrial biopsies performed on the second day after ovulation. The patients had been stimulated with clomiphene citrate (CC) and human chorionic gonadotropin (hCG) (group I); with CC, human menopausal gonadotropin (hMG), and hCG (group II), or with hMG and hCG (group III). Only 17 patients (30%) showed a normal luteal phase histology. The remaining 41 patients (70%) showed variety of endometrial abnormalities. Patients stimulated with hMG and hCG (group III) had a normal luteal phase at a significantly higher rate (48% versus 16%). Women below the age of 35 had a significantly higher rate of normal luteal phase histology than women older than 35 years. The study establishes abnormal endometrial histology as a possible cause of the low pregnancy rate of in vitro fertilization. The degree of endometrial histologic abnormality varies considerably with the type of ovarian stimulation used.