Luteal insufficiency: correlation between endometrial dating and integrated progesterone output in clomiphene citrate-induced cycles

The luteal phase after ovarian stimulation

Evaluation of the luteal phase after ovarian stimulation presents several difficulties. Until today, it has not been proved that in cycles stimulated with clomiphene citrate/human menopausal gonadotrophins, luteal supplementation with progesterone significantly increases implantation rate. On the contrary, it is accepted that in cycles stimulated with GnRH agonists/gonadotrophins, support of the luteal phase is essential for the achievement of pregnancy. In GnRH antagonist cycles luteal supplementation, although widely practised, is not at present supported by randomized controlled trials. Finally, it appears that the combination of gonadotrophin stimulation with human chorionic gonadotrophin results in an inadequate luteal phase with or without the use of either agonists or antagonists.

Is there a role for preparatory cycle in ovum donation recipients?

PURPOSE OF REVIEW

In ovum donation cycles, the role of preparatory cycles to ensure proper endometrial development in the recipient remains controversial. As evidenced in the literature, endometrial receptivity is critical in conception. Therefore, endometrial preparation with exogenous hormones in addition to synchronization of the recipient and donor are essential in achieving a successful outcome.

RECENT FINDINGS

There are very limited data specifically examining the benefit of recipients undergoing preparatory cycles prior to their actual egg donation cycle. One study concluded that trial hormone replacement treatment cycles with endometrial biopsies may be useful in older reproductive-age women but not in younger women. Another study showed no difference in pregnancy rates between those who did and did not undergo preparatory cycles.

SUMMARY

Since one of the integral elements of preparatory cycles is determining endometrial dating, with relatively conflicting data, these mock cycles may not be as beneficial as expected. Therefore, for those who routinely use preparatory cycles, the potential risks, benefits, and costs of these cycles, increased hormonal exposure, the relatively invasive nature of the procedure, and time prior to performing them must be considered.

Histological dating of timed endometrial biopsy tissue is not related to fertility status

OBJECTIVE

To assess the ability of histological dating to discriminate between women of fertile and infertile couples. The utility of histological dating of endometrium in the evaluation of infertile couples is uncertain.

DESIGN

Prospective multicenter study, with subjects randomly assigned to biopsy timing. Criterion standard for infertility was 12 months of unprotected, regular intercourse without conception and for fertility at least one live birth within 2 years.

SETTING

University-based infertility practices.

PATIENT(S)

Volunteer subjects (847) recruited at 12 clinical sites participating in the National Institutes of Health-funded Reproductive Medicine Network. Inclusion criteria included ages 20-39 years, regular menstrual cycles, and no hormonal treatment or contraceptive use for 1 month before the study. Fertile controls were excluded if they had a history of infertility, recurrent pregnancy loss, or recent breastfeeding.

INTERVENTION(S)

Subjects underwent daily urinary LH testing. After detection of the LH surge, subjects were randomized to biopsy in the mid (days 21-22) or the late (days 26-27) luteal phase. Pathologists at each site estimated the cycle day based on standard criteria. For the primary analysis, an out-of-phase biopsy was defined as a greater than 2-day delay in the histological maturation of the endometrium.

MAIN OUTCOME MEASURE(S)

The proportion of out-of-phase biopsies in fertile and infertile women was compared using logistic regression models with age at randomization as a covariate. Comparisons were also made between fertile vs. infertile at the midluteal or late luteal phase time points.

RESULT(S)

Biopsies were evaluated (301 mid and 318 late; N = 619). Out-of-phase biopsy results poorly discriminated between women from fertile and infertile couples in either the midluteal (fertile: 49.4%, infertile: 43.2%) or late luteal phase (fertile: 35.3%, infertile 23.0%). Results did not substantially differ using alternative definitions of "out-of-phase" or standardized cycle day.

CONCLUSION(S)

Histological dating of the endometrium does not discriminate between women of fertile and infertile couples and should not be used in the routine evaluation of infertility.

Regulation of HOXA-10 expression by testosterone in vitro and in the endometrium of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) affects approximately 5% of reproductive-age women and is characterized by anovulation and increased androgen production. Despite the ability to correct ovulatory disorders, pregnancy rates remain paradoxically low, and spontaneous pregnancy loss rates are high. To determine whether uterine dysfunction contributed to the adverse reproductive outcomes in PCOS, we assessed the effect of the increased ovarian androgens on a well-characterized gene essential to endometrial receptivity. Up-regulation of HOXA10 in the endometrium is necessary for receptivity to embryo implantation. In vitro, HOXA10 expression was repressed by testosterone but not by dehydroepiandrosterone, dehydroepiandrosterone sulfate, or insulin. Testosterone also prevented the increased expression of HOXA10 previously reported with estradiol or progesterone. Dihydrotestosterone produced an effect similar to that of testosterone, whereas flutamide blocked the testosterone effect. Endometrial biopsies, obtained from women with PCOS, demonstrated decreased HOXA10 mRNA. Testosterone is a novel regulator of HOXA10. Diminished uterine HOXA10 expression may contribute to the diminished reproduction potential of women with PCOS.

LH pulses and the corpus luteum: the luteal phase deficiency LPD)

The proper function of the GnRH pulse generator in the hypothalamus is essential for normal ovarian function, hence also for proper function of the corpus luteum. During the luteal phase LH pulses stimulate progesterone release, which is essential for normal endometrial transformation. Approximately one-half of all luteal phase deficiencies (LPD) are due to improper function of the GnRH pulse generator. Obviously, following ovulation the increased serum progesterone levels oversuppress the GnRH pulse generator, resulting in too few LH pulses and therefore improper luteal function. Also, latent hyperprolactinemia may lead to an LPD which can be effectively treated with plant extracts containing dopaminergic (prolactin-suppressing) compounds. Our increasing knowledge of auto- and paracrine mechanisms between nonsteroidogenic and steroidogenic cells now allow subclassification of LPDs of ovarian origin. The so-called small luteal cells are LH-responsive. If they develop improperly the regularly occurring LH pulses are unable to stimulate progesterone secretion from the small luteal cells, which results in what we call the small luteal cell defect. In addition, there is also evidence that the large luteal cells may function improperly. Hence, basal progesterone release is too low while LH-stimulated progesterone release from the small luteal cells appears to be intact. This subclassification of luteal phase deficiency results in the suggestion of different treatments. In cases where the corpus luteum is LH-responsive, such as the hypothalamic corpus luteum insufficiency and the large luteal cell defect, HCG treatment or pulsatile treatment with GnRH is advisable. In the case of LH/hCG-unresponsive small luteal cell defect a progesterone substitution is suggested.

Localization and expression of oxytocin receptor and its messenger ribonucleic acid in peri-implantation phase human endometrium during control and clomiphene-treated cycles

OBJECTIVES

This study was undertaken to determine expression levels of oxytocin receptor and its gene in peri-implantation phase human endometrium during clomiphene-treated cycles compared with control cycles.

STUDY DESIGN

Oxytocin receptor and its messenger ribonucleic acid in peri-implantation phase endometrium during control and clomiphene-treated (50 mg days 5 to 9) cycles of 5 healthy fertile women were determined by immunohistochemical methods, Western blot analysis with monoclonal antibody against amino acids 20 through 40 of the extracellular N-terminal human oxytocin receptor, and reverse transcription-polymerase chain reaction with oligonucleotide primers to amplify the 391-base pair fragment of the oxytocin receptor gene.

RESULTS

Oxytocin receptor and its messenger ribonucleic acid were expressed in human peri-implantation phase endometrial samples from both control and clomiphene-treated cycles. The receptor was localized predominantly in the epithelial cells and glands, with little or none detected in the stroma. Oxytocin receptor protein was separated out as a single 70-kd band by Western blot analysis; its relative abundance was significantly reduced during clomiphene-treated cycles. The messenger ribonucleic acid was detected in all endometrium during control and clomiphene-treated cycles, with greater expression during control cycles.

CONCLUSIONS

The expressions of oxytocin receptor and its gene in luteal phase human endometrium suggest a functional relevance in modulation of biochemical changes for implantation.

E-cadherin and its messenger ribonucleic acid in periimplantation phase human endometrium in normal and clomiphene-treated cycles

OBJECTIVE

The purpose of this investigation was to determine whether treatment with clomiphene citrate, which is estrogenic and antiestrogenic, affects the expression of the cell adhesion molecule E-cadherin in human periimplantation phase endometrium.

STUDY DESIGN

Five healthy women were studied for two cycles each, a control and a treated (clomiphene 50 mg daily, days 5 through 9) cycle. A biopsy specimen of endometrial tissue was studied (8 to 10 days post luteinizing hormone surge) for immunohistochemical localization, Western analysis of E-cadherin with use of a highly specific monoclonal antibody to human E-cadherin, and determination of messenger ribonucleic acid for E-cadherin by reverse transcription-polymerase chain reaction by use of oligonucleotide primers specific to E-cadherin and amplifying a 432 bp fragment.

RESULTS

Luteal phase plasma progesterone levels were significantly higher in clomiphene cycles. E-cadherin was immunocytochemically present in endometrium of control and treated cycles with no apparent difference in staining intensity. Western blots revealed the presence of E-cadherin. It was relatively more abundant in clomiphene-treated than control cycles but not significantly different. The message for E-cadherin gene is expressed in endometrium of control (n = 5) and clomiphene cycles (n = 4).

CONCLUSIONS

E-cadherin and its gene transcripts are expressed in periimplantation phase endometrium and are not significantly affected by clomiphene treatment.

Clinical uses of antiestrogens

An antiestrogen is a compound that blocks the action of estrogen. Most synthetic antiestrogens have agonistic or antagonistic activity depending on the tissue and the endogenous estrogen mileu. The triphenylethylene derivatives, clomiphene and tamoxifen, are the antiestrogens in greatest clinical use. Their biologic effects, clinical indications, and risks are reviewed. Novel antiestrogens which are beginning to be studied clinically include the benzothiophene derivative, raloxifene and the "pure" antiestrogens such as ICI 182,780. New clinical indications for existing compounds as well as the development of novel antiestrogens may lead to better treatment options for endocrine-dependent conditions.

Early identification of sites of embryo implantation in rats by means of gadolinium-enhanced MR imaging

To determine if magnetic resonance (MR) imaging techniques can be used to examine sites of embryo implantation in intact rats, pregnant animals were imaged with gadopentetate dimeglumine-enhanced MR imaging approximately 10 hours after initiation of implantation on day 5 of pregnancy. T1-weighted, three-dimensional SPGR (spoiled gradient-recalled acquisition in the steady state) sequences were used to image the volume of abdomen containing the uterine horns before and after injection of gadopentetate dimeglumine into a femoral venous catheter. While unenhanced images provided little detail in uterine tissue, analysis of the gadolinium-enhanced abdominal images with interactive vascular imaging allowed easy identification of sites of embryo implantation along both uterine horns in four of four pregnant rats. These punctate patterns of enhancement match those of macroscopic bluing after injection of Evans blue dye. Similar gadolinium-enhanced MR imaging of nonpregnant rats produced only a slight, generalized enhancement of entire uterine horns. The authors conclude that local increases in extracellular fluid volume, vascular permeability, and blood flow in the uterus may all contribute to the gadolinium enhancement of the implantation sites. They propose that this approach can be used in experimental settings to provide information regarding embryo implantation unaccessible with traditional approaches. In clinical settings, gadolinium-enhanced MR imaging may be used to examine potential causes of infertility, including luteal phase defects.

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.