Luteal phase defect: the possibility of an immunohistochemical diagnosis

Endogenous progesterone in unexplained infertility: a systematic review and meta-analysis

PURPOSE

To investigate the possibility that altered actions of endogenous progesterone affect receptivity and contribute to unexplained infertility (UI).

METHODS

Two authors electronically searched MEDLINE, CINAHL and Embase databases from inception to 6 July 2022 and hand-searched according to Cochrane methodology. We included all published primary research reporting outcomes related to endogenous progesterone in natural cycles in women with UI. Studies were assessed for risk of bias using a modified Newcastle-Ottawa Score or NHLBI Score. We pooled results where appropriate using a random-effects model. Findings were reported as odds ratios or mean differences.

RESULTS

We included 41 studies (n = 4023). No difference was found between the mid-luteal serum progesterone levels of women with UI compared to fertile controls (MD 0.74, - 0.31-1.79, I² 36%). Women with UI had significantly higher rates of 'out-of-phase' endometrium than controls. Nine out of 10 progesterone-mediated markers of endometrial receptivity were significantly reduced in women with UI compared to fertile controls (the remaining 1 had conflicting results). Resistance in pelvic vessels was increased and perfusion of the endometrium and sub-endometrium reduced in UI compared to fertile controls in all included studies. Progesterone receptor expression and progesterone uptake were also reduced in women with unexplained infertility.

CONCLUSIONS

End-organ measures of endogenous progesterone activity are reduced in women with UI compared to fertile controls. This apparently receptor-mediated reduction in response affects endometrial receptivity and is implicated as the cause of the infertility. Further research is required to confirm whether intervention could overcome this issue, offering a new option for treating unexplained infertility.

TRIAL REGISTRATION

PROSPERO registration: CRD42020141041 06/08/2020.

Integrins in the endometrium

The endometrium expresses many of the same integrins displayed by other tissues. Endometrial epithelial cells maintain the ‘classic’ epithelial integrins, including α2, α3, α6, and β4, while the stroma expresses the fibronectin receptor, α5β1. During the menstrual cycle, the endometrium undergoes dynamic changes in morphology in preparation for implantation. With these histological changes are concomitant alterations in integrin expression that appear to ‘frame’ the window of implantation, by the co-expression of glandular αvβ3 and α4β1 during days 20 to 24 of the menstrual cycle. The changes in integrin expression shift from epithelial to stroma predominance late in the menstrual cycle, extending into early pregnancy. Decidual integrins that appear upregulated in pregnancy include α1β1, α3β1, α6β1 and αvβ3. Markers of uterine receptivity hold promise for a better understanding of the implantation process and may help to explain many different types of infertility. These markers will be essential for monitoring and improving infertility therapies. The importance of integrins in the human endometrium now seems well established and promises to be an area of great clinical and basic science activity in the future.

Differential expression of L-selectin ligand in the endometrium during the menstrual cycle

OBJECTIVE

To evaluate the expression of L-selectin ligand in the endometrium during the menstrual cycle.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

PATIENT(S)

Endometrial samples from regularly cycling women.

INTERVENTION(S)

Tissue microarray and immunohistochemical staining were performed using L-selectin ligand monoclonal antibody (MECA-79).

MAIN OUTCOME MEASURE(S)

Expression of L-selectin ligand in the various phases of menstrual cycle was measured by a semiquantitative analysis (HSCORE) for the intensity of immunohistochemical reactivity.

RESULT(S)

In the luminal epithelium, there were significant differences in L-selectin ligand expression during the proliferative, interval, early secretory, and midsecretory phases. The expression of L-selectin ligand was greatest from the periovulatory interval through midsecretory phase. In the glandular epithelium, the expression of L-selectin ligand was greatest in midsecretory phase with significant differences between proliferative phase and the midsecretory phase and between the interval phase and the midsecretory phase.

CONCLUSION(S)

Increased expression of L-selectin ligand in the human endometrium during the early and midsecretory phases of the menstrual cycle may be related to the process of implantation.

Two pathways of progesterone action in the human endometrium: implications for implantation and contraception

The endometrium is the site of implantation and pregnancy. Preparation for this important biological event relies primarily on progesterone, which takes the estrogen-primed endometrium toward a state of receptivity. As a steroid target tissue, the endometrium is also prone to abnormal growth sometimes leading to the development of hyperplasia or cancer. It is the balance between estrogen and progesterone that maintains the endometrium in a state of health and provides the synchronous timing necessary for a successful implantation to occur. In our efforts to understand the role of progesterone in the endometrium we have focused on the use of specific protein biomarkers. Based on examination of a cell adhesion molecule, the alphavbeta3 integrin, and its ligand, osteopontin, we have come to conclude that progesterone action can be direct or indirect. Progesterone acting on the stromal compartment provides paracrine mediators that influence epithelial gene expression. Conversely, acting directly, progesterone may primarily stimulate gene expression of the endometrial epithelium. The complexity of the system is extended since progesterone itself works through two different receptor isoforms. Regulated differential expression of PR-A versus PR-B also appears to fine tune the effect of progesterone on specific genes. Progesterone may also inhibit specific genes that undergo cyclic variation during the menstrual cycle. Together, using in vitro models we have shown that progesterone dynamically regulates gene expression in the endometrium and that imbalances between estrogen and progesterone may have far reaching consequences on normal cycle fecundity and on the balance between health and disease in this hormone-target tissue.

Expression of alpha6 and beta4 integrin subunits throughout the menstrual cycle: no correlation with uterine receptivity

OBJECTIVE

To compare the expression of alpha6 and beta4 integrin subunit levels throughout the menstrual cycle in the endometrium of healthy women and infertile women.

DESIGN

Prospective study.

SETTING

An academic teaching hospital.

PATIENT(S)

Endometrium was collected from 58 women, including healthy subjects (n = 28) and patients undergoing diagnostic testing for infertility (n = 30).

INTERVENTION(S)

Endometrial biopsies were performed throughout the menstrual cycle in healthy women and infertile women.

MAIN OUTCOME MEASURE(S)

Immunohistochemical staining intensity of alpha6 and beta4 using the semiquantitative immunohistochemical score, compared using regression analysis and analysis of variance with Scheffé's correction.

RESULT(S)

There was no correlation between menstrual cycle phase and endometrial integrin subunit alpha6 or beta4 on glandular or luminal epithelium. Even women with identified luteal phase defects had indistinguishable patterns of expression for these integrin subunits during the window of implantation.

CONCLUSION(S)

The integrin subunits alpha6 and beta4 are expressed uniformly throughout the menstrual cycle on glandular and luminal epithelium. These integrins may have a housekeeping role in anchoring endometrial epithelium and do not appear to be useful markers of uterine receptivity.

MUC1 as a cell surface and secretory component of endometrial epithelium: reduced levels in recurrent miscarriage

The mucin MUC1 is a large, highly glycosylated, hormonally regulated product of endometrial glandular and luminal epithelium with both cell surface-associated and secreted isoforms. The abundance of mRNA coding for MUC1 increases about sixfold from the proliferative to the early secretory phase (Hey et al., J. Clin. Endocrinol. Metab. 78:337-342, 1994). Immunohistochemical studies show intracellular deposits accumulating in the early secretory phase followed by the release of MUC1 into gland lumens. The apical surface of luminal epithelium is strongly immunopositive in the early secretory phase. We have used a two site ELISA to measure MUC1 in uterine flushings as a function of time after the luteinising hormone (LH) peak. Low levels of secretory MUC1 are observed before day LH+7, while values on days LH+7-LH+13 are much higher. Using semi-quantitative immunohistochemical methods we have shown that in women suffering recurrent spontaneous miscarriage, mid secretory phase levels of MUC1 core protein and mucin-associated glycans are reduced (Serle et al., Fertil. Steril. 62:989-996, 1994). Similarly, lower core protein levels are observed in uterine flushings after day LH+7 in these women. Reduced epithelial secretory function and a resultant change in uterine fluid composition are features of endometrium from recurrent miscarriage patients.

The efficacy of immunotherapy in patients who underwent superovulation with intrauterine insemination

OBJECTIVE

To determine if the immunotherapy with corticosteroids would improve pregnancy rate in infertile patients with ovulatory factor and patients with unexplained infertility who undergo superovulation with IUI.

DESIGN

Prospective, controlled study.

SETTING

Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Ulsan, Seoul, Korea.

PATIENTS

Nine-one infertile patients with ovulatory factors and 78 patients with unexplained infertility who underwent superovulation with IUI.

RESULTS

The prevalence of autoantibodies (antinuclear antibody, lupus anticoagulant, anticardiolipin antibody, antidouble-stranded DNA antibody) was elevated significantly in patients with unexplained infertility compared with patients with ovulatory infertility (20.5% versus 3.3%). Forty-five patients with ovulatory factor underwent 72 cycles of superovulation with IUI, receiving corticosteroids. Thirty-eight patients with unexplained infertility underwent 75 cycles of superovulation with IUI, receiving corticosteroids. Forty-six patients with ovulatory factor who underwent 66 cycles of superovulation with IUI and 40 patients with unexplained infertility who underwent 75 cycles of superovulation with IUI served as controls, not receiving corticosteroids. In patients with ovulatory factor, there were no significant differences between the corticosteroid treatment group and control group in clinical pregnancy rate (38.9% versus 33.3%) or in spontaneous abortion rate (14.3% versus 13.6%). In patients with unexplained infertility, there was a significantly higher clinical pregnancy rate per cycle in the corticosteroid treatment group, with 45.3% (34/75) compared with 29.3% (22/75) in the control group but no difference between the corticosteroid treatment and control groups in spontaneous abortion rate (17.6% versus 13.6%). There were no side effects due to the use of corticosteroids.

Endometrial differentiation in the peri-implantation phase of women with recurrent miscarriage: a morphological and immunohistochemical study

OBJECTIVES

To study endometrial differentiation in the peri-implantation phase of women with recurrent miscarriage and to compare the results with endometrium of normal fertile women.

DESIGN

A prospective study of endometrial specimens precisely timed from the LH surge, using traditional histologic dating (Noyes' criteria), quantitative histologic measurement (morphometric analysis), and immunohistochemical techniques.

RESULTS

Fifteen of 25 (60%) subjects in the recurrent miscarriage group had retarded endometrial development in the peri-implantation period as monitored by morphometry. The recurrent miscarriage group showed reduced levels of four mucin-related secretory epitopes, and greater reductions were associated with morphological retardation. Normal differentiation was observed in all of the 14 subjects in the control group.

CONCLUSIONS

Women with idiopathic recurrent pregnancy loss may be divided into two distinct subgroups on the basis of their endometrial response in the peri-implantation period. Precisely timed endometrial biopsy should be incorporated in the investigation of recurrent miscarriage.

Endometrial structure after superovulation: a prospective controlled study

OBJECTIVE

To demonstrate the effect of superovulation using a GnRH agonist (GnRH-a) and hMG and hCG on endometrial structure.

DESIGN

Prospective, case-controlled study.

SETTING

Tertiary referral assisted reproduction unit in an academic department.

PATIENTS

Eleven women undergoing GIFT or IVF, without ET.

INTERVENTIONS

All women were treated with a long stimulation regimen using the depot GnRH-a Goserelin (ICI, Macclesfield, United Kingdom) and hMG and hCG.

MAIN OUTCOME MEASURES

Comparison of endometrial biopsy specimens taken 4 days after ovulation in an unstimulated cycle with specimens taken 4 days after oocyte recovery, using standard dating criteria and morphometric analysis.

RESULTS

There was no difference in endometrial glandular development as assessed by either standard criteria or morphometric analysis.

CONCLUSIONS

Superovulation preceded by pituitary down regulation is not associated with abnormal endometrial glandular development, even though supraphysiological levels of E2 and P are induced.

Immunohistochemical markers of uterine receptivity in the human endometrium

The factors responsible for the initial interaction between maternal and fetal epithelium leading to the establishment of pregnancy remain poorly understood. Temporal and spatial expression of specific endometrial peptides in response to ovarian steroids is thought to contribute to the development of a period of uterine receptivity, whereby the endometrium becomes hospitable to the implanting blastocyst. The failure to establish receptivity may account for a significant percentage of the cases of infertility in the female, especially affecting women with luteal phase deficiency, leiomyomata uteri, endometriosis, habitual abortion, and unexplained infertility. In addition, despite increasing global experience with advanced reproductive technologies, the majority of In Vitro Fertilization (IVF) attempts remain unsuccessful, most likely on the basis of implantation failure. In this article, we review the concepts involved in the study of uterine receptivity in the human, highlight potential immunohistochemical (IHC) markers that have recently been discovered, and discuss how IHC assessment of the endometrium is a potentially valuable method for the evaluation of the receptive endometrial state. Using this approach we have examined several new potential markers of uterine receptivity. Endometrial progesterone receptors and one of the integrin cell adhesion molecules appear to undergo changes in expression around the time of implantation, and may be sensitive indicators of the receptive state. Further, these markers are delayed in women with infertility and luteal phase deficiency. These studies illustrate the utility of IHC diagnosis for the evaluation of endometrial function.

Structure of premenstrual endometrium in HMG + HCG induced anovulatory women

In this study structural alterations were tested on anovulatory infertile women who had undergone treatment of HMG + HCG to induce ovulation and subsequently to achieve pregnancy. For this purpose, a single premenstrual endometrial fundal biopsy was performed and evaluated using light and electron microscopy. The aim of the study was to evaluate the biopsies with respect to 'in-phase' or 'out-of-phase' at light microscopic level, in which a series of strict criteria were chosen, and then to detect the additional structural abnormalities at electron microscopic level, if present. Only one of the women in our study who had an in-phase endometrium became pregnant after proper treatment protocol individually adjusted and consequently terminated by an early abortion. Histologic features of the biopsies revealed that about half were normal while the rest had various types of structural abnormalities in the transformation of the secretory endometrium detected by light and/or electron microscopy. At the electron microscopic level, multiple alterations were seen in cellular and intercellular components even in those diagnosed as normal by light microscopy. As a result of the above data it was concluded that the cause of inconceivability might arise from some fine structural alterations which may affect the endometrial receptivity of an implanting embryo.

An endometrial factor in unexplained infertility

OBJECTIVE

To study a group of women with unexplained infertility to see whether they have a defect that is intrinsic to the endometrium.

DESIGN

Evaluation of the functional response of the endometrium by examining endometrial biopsy specimens using immunohistochemical methods in a group of women with unexplained infertility and in a control group of women with normal fertility.

PATIENTS

27 Women with unexplained infertility (average age 33.2); median duration of infertility five years. A control group of 44 women with normal fertility (average age 33.8) who were requesting sterilisation or reversal of sterilisation.

SETTING

Infertility clinic, Jessop Hospital for Women, Sheffield.

INTERVENTION

Secretory phase endometrial biopsy specimens were taken, with informed consent, as an outpatient procedure.

MAIN OUTCOME MEASURES

Immunohistochemistry with monoclonal antibody D9B1, was used to assess the production and secretion of an oligosaccharide epitope produced by endometrial gland cells between two and seven days after the luteinising hormone surge. A reflected light measuring system was used to assess the amount of epitope within the gland cells, and in the gland lumen.

RESULTS

In the control group of women, mean reflected light measurements at the cell base and cell apex peaked at three and five days after the luteinising hormone surge respectively, and in the gland lumen the epitope accumulated rapidly from three days, reaching a peak at seven days. In the women with infertility the peaks of epitope at the cell base and cell apex were lower, broader, and delayed in onset, and the build up of epitope in the gland lumen was retarded. The synthesis and secretion of the epitope in the women with infertility was therefore significantly reduced and delayed, even in the presence of normal concentrations of circulating progesterone.

CONCLUSIONS

The results suggest that a primary dysfunction of the endometrium might be associated with hitherto unexplained infertility.

Menstrual-cycle-dependent expression of keratan sulphate in human endometrium

Immunochemical methods have been used to detect and characterize two classes of polypeptide-associated keratan sulphate (KS) in epithelial secretions from human endometrium. Monoclonal antibody D9B1 binds to a hormonally regulated sialylated epitope associated with KS in a high relative molecular mass (250,000-350,000) component that bands as a doublet in SDS/PAGE. These KS chain(s) are sensitive to keratanase, endo-beta-galactosidase and N-glycanase. A second, more highly sulphated, type of KS is also present, that is resistant to all three enzymes. This can be detected using monoclonal antibody 5D4. It is present throughout the menstrual cycle and is associated principally with a component of Mr 140,000. Thus secretory KS contributes to the environment of the implanting embryo, may be used as a molecular index of endometrial function and could be important in the establishment of pregnancy.

The effect of the intrauterine contraceptive device on endometrial secretory function: a possible mode of action

The effect of the intrauterine contraceptive device (IUD) on the composition of endometrial secretion has been studied using the monoclonal antibody D9B1. The antibody binds to a polypeptide-associated oligosaccharide epitope that is secreted by endometrial epithelium in the secretory phase with a maximum around the time of implantation. In endometria affected by the IUD in situ, a significant reduction in epitope expression has been observed using immunohistochemistry. This defect can occur against a background of normal secretory differentiation and in the expectation of normal ovarian stimulus. The data provide new insight into the contraceptive mechanisms of action of the IUD.