The impact of ovarian stimulation on the human endometrial microenvironment

STUDY QUESTION

How does ovarian stimulation (OS), which is used to mature multiple oocytes for ART procedures, impact the principal cellular compartments and transcriptome of the human endometrium in the periovulatory and mid-secretory phases?

SUMMARY ANSWER

During the mid-secretory window of implantation, OS alters the abundance of endometrial immune cells, whereas during the periovulatory period, OS substantially changes the endometrial transcriptome and impacts both endometrial glandular and immune cells.

WHAT IS KNOWN ALREADY

Pregnancies conceived in an OS cycle are at risk of complications reflective of abnormal placentation and placental function. OS can alter endometrial gene expression and immune cell populations. How OS impacts the glandular, stromal, immune, and vascular compartments of the endometrium, in the periovulatory period as compared to the window of implantation, is unknown.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study carried out between 2020 and 2022 included 25 subjects undergoing OS and 25 subjects in natural menstrual cycles. Endometrial biopsies were performed in the proliferative, periovulatory, and mid-secretory phases.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Blood samples were processed to determine serum estradiol and progesterone levels. Both the endometrial transcriptome and the principal cellular compartments of the endometrium, including glands, stroma, immune, and vasculature, were evaluated by examining endometrial dating, differential gene expression, protein expression, cell populations, and the three-dimensional structure in endometrial tissue. Mann-Whitney U tests, unpaired t-tests or one-way ANOVA and pairwise multiple comparison tests were used to statistically evaluate differences.

MAIN RESULTS AND THE ROLE OF CHANCE

In the periovulatory period, OS induced high levels of differential gene expression, glandular-stromal dyssynchrony, and an increase in both glandular epithelial volume and the frequency of endometrial monocytes/macrophages. In the window of implantation during the mid-secretory phase, OS induced changes in endometrial immune cells, with a greater frequency of B cells and a lower frequency of CD4 effector T cells.

LARGE SCALE DATA

The data underlying this article have been uploaded to the Genome Expression Omnibus/National Center for Biotechnology Information with accession number GSE220044.

LIMITATIONS, REASONS FOR CAUTION

A limited number of subjects were included in this study, although the subjects within each group, natural cycle or OS, were homogenous in their clinical characteristics. The number of subjects utilized was sufficient to identify significant differences; however, with a larger number of subjects and additional power, we may detect additional differences. Another limitation of the study is that proliferative phase biopsies were collected in natural cycles, but not in OS cycles. Given that the OS cycle subjects did not have known endometrial factor infertility, and the comparisons involved subjects who had a similar and robust response to stimulation, the findings are generalizable to women with a normal response to OS.

WIDER IMPLICATIONS OF THE FINDINGS

OS substantially altered the periovulatory phase endometrium, with fewer transcriptomic and cell type-specific changes in the mid-secretory phase. Our findings show that after OS, the endometrial microenvironment in the window of implantation possesses many more similarities to that of a natural cycle than does the periovulatory endometrium. Further investigation of the immune compartment and the functional significance of this cellular compartment under OS conditions is warranted.

STUDY FUNDING/COMPETING INTERESTS

Research reported in this publication was supported by the National Institute of Allergy and Infectious Diseases (R01AI148695 to A.M.B. and N.C.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01HD109152 to R.A.), and the March of Dimes (5-FY20-209 to R.A.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or March of Dimes. All authors declare no conflict of interest.

Impaired receptivity of thin endometrium: therapeutic potential of mesenchymal stem cells

The endometrium is a resilient and highly dynamic tissue, undergoing cyclic renewal in preparation for embryo implantation. Cyclic endometrial regeneration depends on the intact function of several cell types, including parenchymal, endothelial, and immune cells, as well as adult stem cells that can arise from endometrial or extrauterine sources. The ability of the endometrium to undergo rapid, repeated regeneration without scarring is unique to this tissue. However, if this tissue renewal process is disrupted or dysfunctional, women may present clinically with infertility due to endometrial scarring or persistent atrophic/thin endometrium. Such disorders are rate-limiting in the treatment of female infertility and in the success of in vitro fertilization because of a dearth of treatment options specifically targeting the endometrium. A growing number of studies have explored the potential of adult stem cells, including mesenchymal stem cells (MSCs), to treat women with disorders of endometrial regeneration. MSCs are multipotent adult stem cells with capacity to differentiate into cells such as adipocytes, chondrocytes, and osteoblasts. In addition to their differentiation capacity, MSCs migrate toward injured sites where they secrete bioactive factors (e.g. cytokines, chemokines, growth factors, proteins and extracellular vesicles) to aid in tissue repair. These factors modulate biological processes critical for tissue regeneration, such as angiogenesis, cell migration and immunomodulation. The MSC secretome has therefore attracted significant attention for its therapeutic potential. In the uterus, studies utilizing rodent models and limited human trials have shown a potential benefit of MSCs and the MSC secretome in treatment of endometrial infertility. This review will explore the potential of MSCs to treat women with impaired endometrial receptivity due to a thin endometrium or endometrial scarring. We will provide context supporting leveraging MSCs for this purpose by including a review of mechanisms by which the MSC secretome promotes regeneration and repair of nonreproductive tissues.

Mesenchymal stem cell secretome alters gene expression and upregulates motility of human endometrial stromal cells

In brief

Endometrial stromal cell motility is fundamental to regeneration and repair of this tissue and crucial for successful reproduction. This paper shows a role for the mesenchymal stem cell (MSC) secretome in enhancing endometrial stromal cell motility.

Abstract

Cyclic regeneration and repair of the endometrium are crucial for successful reproduction. Mesenchymal stem cells (MSCs) derived from bone marrow (BM-MSC) and umbilical cord (UC-MSC) facilitate tissue repair via their secretome, which contains growth factors and cytokines that promote wound healing. Despite the implication of MSCs in endometrial regeneration and repair, mechanisms remain unclear. This study tested the hypothesis that the BM-MSC and UC-MSC secretomes upregulate human endometrial stromal cell (HESC) proliferation, migration, and invasion and activate pathways to increase HESC motility. BM-MSCs were purchased from ATCC and cultured from the BM aspirate of three healthy female donors. UC-MSCs were cultured from umbilical cords of two healthy male term infants. Using indirect co-culture of MSCs and hTERT-immortalized HESCs via a transwell system, we demonstrated that co-culture of HESCs with BM-MSCs or UC-MSCs from all donors significantly increased HESC migration and invasion, whereas effects on HESC proliferation varied among BM-MSC and UC-MSC donors. Analysis of gene expression by mRNA sequencing and RT-qPCR showed that expression of CCL2 and HGF was upregulated in HESCs that had been cocultured with BM-MSCs or UC-MSCs. Validation studies revealed that exposure to recombinant CCL2 for 48 h significantly increased HESC migration and invasion. Increased HESC motility by the BM-MSC and UC-MSC secretome appears to be mediated in part by upregulated HESC CCL2 expression. Our data support the potential for leveraging MSC secretome as a novel cell-free therapy to treat disorders of endometrial regeneration.

Expression of glucocorticoid and androgen receptors in bone marrow-derived hematopoietic and nonhematopoietic murine endometrial cells

OBJECTIVE

To determine whether bone marrow (BM)-derived cells engrafting the murine endometrium express the glucocorticoid receptor (GR) and androgen receptor (AR). Recent data demonstrate that BM is a long-term source of multiple hematopoietic and nonhematopoietic endometrial cell types. Important roles for glucocorticoids and androgens in regulating endometrial functions, including decidualization and early embryo attachment/invasion, have very recently emerged. Whether endometrial cells of BM origin express glucocorticoid or ARs has not been previously studied.

DESIGN

Animal study.

SETTING

Basic science laboratory.

ANIMAL(S)

Wild-type C57BL/6J male mice expressing enhanced green fluorescent protein (GFP) and syngeneic wild-type C57BL/6J female mice aged 6-9 weeks.

INTERVENTION(S)

Murine bone marrow transplant.

MAIN OUTCOME MEASURE(S)

Bone marrow cells were harvested from adult wild-type C57BL/6 mice and subjected to flow cytometry to identify the percentage of hematopoietic and nonhematopoietic cells expressing GR or AR. Uterine tissue sections from lethally irradiated syngeneic adult female C57BL/6 mice that had been recipients of BM transplants from adult male transgenic donor mice ubiquitously expressing GFP were studied. Immunohistochemistry was performed in the uterine tissue sections of the recipient mice at 5, 9, and 12 months after transplant using specific anti-GR, anti-AR, anti-GFP, anti-CD45 (pan leukocyte marker), and anti-F4/80 (murine macrophage marker) primary antibodies. Confocal laser microscopy was used to localize and quantitate BM-derived (GFP⁺) cell types in the endometrial stromal and epithelial compartments and determine whether BM-derived cell types in the murine endometrium express GR or AR.

RESULT(S)

Hematopoietic cells comprised 93.6%-96.6% of all cells in the BM, of which 98.1% ± 0.2% expressed GR and 92.2% ± 4.4% expressed AR. Nonhematopoietic cells comprised 0.4%-1.3% of BM, of which 52.8% ± 5.9% expressed GR and 48.9% ± 3.4% expressed AR. After BM transplant, the proportion of cells originating from BM in the endometrial stromal compartment increased over time, reaching 13.5% ± 2.3% at 12 months after transplant. In the epithelial compartments, <1% of the cells were of BM origin at 12 months after transplant. Most (60%-72%) GR⁺ and/or AR⁺ BM-derived cells in the stroma were hematopoietic (CD45⁺) cells, of which 37%-51% were macrophages. Nonetheless, 28%-33% of GR⁺ cells, and 28%-40% of AR⁺ BM-derived cells, were nonhematopoietic (CD45^-) stromal cells of BM origin.

CONCLUSION(S)

A substantial number of BM-derived cells express GR and AR, suggesting a role for these cells in both glucocorticoid-regulated and androgen-regulated endometrial functions, such as proliferation and/or decidualization.

Endocrine disruptors and female fertility: a review of pesticide and plasticizer effects

An ongoing interest in environmental exposures and female fertility has led to an increasing number of studies focusing on endocrine-disrupting chemicals (EDCs). Both natural and synthetic compounds have the ability to impact reproductive health by altering the structure and/or function of genes and proteins that facilitate normal ovarian and endometrial functions. This mini-review aims to summarize the effects of some of the most common EDCs on female fertility, including the effects of pesticides and plasticizer alternatives (phthalates, bisphenol A), based on available data in human studies. A literature search was performed using the key words “pesticides, fertility, reproduction, plasticizers, bisphenol A, phthalate, miscarriage, and in vitro fertilization.” The data supporting EDCs’ role in female infertility remain limited, but existing evidence suggests that exposure may have an adverse impact. Accumulating evidence in animal studies provides important insights into the mechanisms underlying EDC effects. As dose-response dynamics are better elucidated, understanding the effects of EDCs on female fertility will help in the development of guidelines for both industry and individuals.

Towards an Improved Understanding of the Effects of Elevated Progesterone Levels on Human Endometrial Receptivity and Oocyte/Embryo Quality during Assisted Reproductive Technologies

Ovarian stimulation is an indispensable part of IVF and is employed to produce multiple ovarian follicles. In women who undergo ovarian stimulation with gonadotropins, supraphysiological levels of estradiol, as well as a premature rise in progesterone levels, can be seen on the day of hCG administration. These alterations in hormone levels are associated with reduced embryo implantation and pregnancy rates in IVF cycles with a fresh embryo transfer. This article aims to improve the reader’s understanding of the effects of elevated progesterone levels on human endometrial receptivity and oocyte/embryo quality. Based on current clinical data, it appears that the premature rise in progesterone levels exerts minimal or no effects on oocyte/embryo quality, while advancing the histological development of the secretory endometrium and displacing the window of implantation. These clinical findings strongly suggest that reduced implantation and pregnancy rates are the result of a negatively affected endometrium rather than poor oocyte/embryo quality. Understanding the potential negative impact of elevated progesterone levels on the endometrium is crucial to improving implantation rates following a fresh embryo transfer. Clinical studies conducted over the past three decades, many of which have been reviewed here, have greatly advanced our knowledge in this important area.

Bone Marrow-Derived Cells in Endometrial Cancer Pathogenesis: Insights from Breast Cancer

Endometrial cancer is the most common gynecological cancer, representing 3.5% of all new cancer cases in the United States. Abnormal stem cell-like cells, referred to as cancer stem cells (CSCs), reside in the endometrium and possess the capacity to self-renew and differentiate into cancer progenitors, leading to tumor progression. Herein we review the role of the endometrial microenvironment and sex hormone signaling in sustaining EC progenitors and potentially promoting dormancy, a cellular state characterized by cell cycle quiescence and resistance to conventional treatments. We offer perspective on mechanisms by which bone marrow-derived cells (BMDCs) within the endometrial microenvironment could promote endometrial CSC (eCSC) survival and/or dormancy. Our perspective relies on the well-established example of another sex hormone-driven cancer, breast cancer, in which the BM microenvironment plays a crucial role in acquisition of CSC phenotype and dormancy. Our previous studies demonstrate that BMDCs migrate to the endometrium and express sex hormone (estrogen and progesterone) receptors. Whether the BM is a source of eCSCs is unknown; alternatively, crosstalk between BMDCs and CSCs within the endometrial microenvironment could be an additional mechanism supporting eCSCs and tumorigenesis. Elucidating these mechanisms will provide avenues to develop novel therapeutic interventions for EC.

Mouse Cre drivers: tools for studying disorders of the human female neuroendocrine-reproductive axis†

Benign disorders of the human female reproductive system, such primary ovarian insufficiency and polycystic ovary syndrome are associated with infertility and recurrent miscarriage, as well as increased risk of adverse health outcomes, including cardiovascular disease and type 2 diabetes. For many of these conditions, the contributing molecular and cellular processes are poorly understood. The overarching similarities between mice and humans have rendered mouse models irreplaceable in understanding normal physiology and elucidating pathological processes that underlie disorders of the female reproductive system. The utilization of Cre-LoxP recombination technology, which allows for spatial and temporal control of gene expression, has identified the role of numerous genes in development of the female reproductive system and in processes, such as ovulation and endometrial decidualization, that are required for the establishment and maintenance of pregnancy in mammals. In this comprehensive review, we provide a detailed overview of Cre drivers with activity in the neuroendocrine-reproductive axis that have been used to study disruptions in key intracellular signaling pathways. We first summarize normal development of the hypothalamus, pituitary, ovary, and uterus, highlighting similarities and differences between mice and humans. We then describe human conditions resulting from abnormal development and/or function of the organ. Finally, we describe loss-of-function models for each Cre driver that elegantly recapitulate some key features of the human condition and are associated with impaired fertility. The examples we provide illustrate use of each Cre driver as a tool for elucidating genetic and molecular underpinnings of reproductive dysfunction.

The incidence of ectopic/heterotopic pregnancies after blastocyst-stage frozen-thawed embryo transfers compared with that after cleavage-stage: a Society for Assisted Reproductive Technologies Clinical Outcomes Reporting System study

Objective

To investigate whether there is a difference in the ectopic/heterotopic pregnancy rate of blastocyst-stage frozen-thawed embryo transfers (FETs) compared with that of cleavage-stage FETs.

Design

A retrospective cohort study.

Setting

Not applicable.

Patient(s)

Women undergoing autologous FETs at either the blastocyst stage (n = 118,572) or the cleavage stage (n = 117,619), as reported to the Society for Assisted Reproductive Technology from 2004 to 2013.

Intervention(s)

None.

Main Outcome Measure(s)

Pregnancy outcomes, specifically ectopic pregnancy rates and heterotopic pregnancy rates.

Result(s)

Among those who became pregnant, there was a significantly lower incidence of ectopic/heterotopic pregnancies in blastocyst-stage FETs versus that in cleavage-stage FETs (0.8% vs. 1.1%). The differences in ectopic/heterotopic pregnancy rates remained statistically significant after controlling for confounders such as tubal factor infertility and number of embryos transferred.

Conclusion(s)

Blastocyst-stage FET was associated with a lower ectopic/heterotopic pregnancy rate compared with cleavage-stage FET.

Pregnancy outcomes following in vitro fertilization frozen embryo transfer (IVF-FET) with or without preimplantation genetic testing for aneuploidy (PGT-A) in women with recurrent pregnancy loss (RPL): a SART-CORS study

STUDY QUESTION

Can preimplantation genetic testing for aneuploidy (PGT-A) improve the live birth rate in patients with recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

PGT-A use was associated with improved live birth rates in couples with recurrent pregnancy loss undergoing frozen embryo transfer (IVF-FET).

WHAT IS KNOWN ALREADY

Euploid embryo transfer is thought to optimize outcomes in some couples with infertility. There is insufficient evidence, however, supporting this approach to management of recurrent pregnancy loss.

STUDY DESIGN, SIZE, DURATION

This study included data collected by the Society of Assisted Reproductive Technologies Clinical Outcomes Reporting System (SART-CORS) for IVF-FET cycles between years 2010 through 2016. A total of 12 631 FET cycles in 10 060 couples were included in this analysis designed to assess the utility of PGT-A in couples with RPL undergoing FET, including 4287 cycles in couples with tubal disease who formed a control group.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The experimental group included couples with RPL (strictly defined as a history of 3 or more pregnancy losses) undergoing FET with or without PGT-A. The primary outcome was live birth rate. Secondary outcomes included rates of clinical pregnancy, spontaneous abortion, and biochemical pregnancy loss. Differences were analyzed using generalized estimating equations logistic regression models to account for multiple cycles per patient. Covariates included in the model were age, gravidity, geographic region, race/ethnicity, smoking history, and indication for assisted reproductive technologies. Analyses were stratified for age groups as defined by SART: <35 years, 35-37 years, 38-40 years, 41-42 years, and >42 years.

MAIN RESULTS AND THE ROLE OF CHANCE

In women with a diagnosis of RPL, the adjusted odds ratio (OR) comparing IVF-FET with PGT-A versus without PGT-A for live birth outcome was 1.31 (95% CI: 1.12, 1.52) for age <35 years, 1.45 (95% CI: 1.21, 1.75) for ages 35-37 years, 1.89 (95% CI: 1.56, 2.29) for ages 38-40, 2.62 (95% CI: 1.94-3.53) for ages 41-42, and 3.80 (95% CI: 2.52, 5.72) for ages >42 years. For clinical pregnancy, the OR was 1.26 (95% CI: 1.08, 1.48) for age <35 years, 1.37 (95% CI: 1.14, 1.64) for ages 35-37 years, 1.68 (95% CI: 1.40, 2.03) for ages 38-40 years, 2.19 (95% CI: 1.65, 2.90) for ages 41-42, and 2.31 (95% CI: 1.60, 3.32) for ages >42 years. Finally, for spontaneous abortion, the OR was 0.95 (95% CI: 0.74, 1.21) for age <35 years, 0.85 (95% CI: 0.65, 1.11) for ages 35-37 years, 0.81 (95% CI: 0.60, 1.08) for ages 38-40, 0.86 (95% CI: 0.58, 1.27) for ages 41-42, and 0.58 (95% CI: 0.32, 1.07) for ages >42 years.

LIMITATIONS, REASONS FOR CAUTION

The retrospective collection of data including only women with recurrent pregnancy loss undergoing FET presents a limitation of this study, and results may not be generalizable to all couples with recurrent pregnancy loss. Also, data regarding evaluation and treatment for RPL for the included women is unavailable.

WIDER IMPLICATIONS OF THE FINDINGS

This is the largest study to date assessing the utility of PGT-A in women with RPL. PGT-A was associated with improvement in live birth and clinical pregnancy in women with RPL, with the largest difference noted in the group of women with age greater than 42 years. Couples with RPL warrant counseling on all management options to reduce subsequent miscarriage, which may include IVF with PGT-A for euploid embryo selection.

STUDY FUNDING/COMPETING INTEREST(S)

There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Increased male live-birth rates after blastocyst-stage frozen-thawed embryo transfers compared with cleavage-stage frozen-thawed embryo transfers: a SART registry study

Objective

To investigate whether there is a difference in live-birth gender rates in blastocyst-stage frozen-thawed embryo transfers (FETs) compared with those in cleavage-stage FETs.

Design

Retrospective cohort study.

Setting

Academic medical center.

Patient(s)

All women with recorded live births who underwent FET at either the blastocyst or cleavage stage, reported to the Society for Assisted Reproductive Technology during 2004–2013.

Intervention(s)

None.

Main Outcome Measure(s)

The primary outcome was live-birth gender rates. Demographic criteria were also collected. The chi-square analyses were used for bivariate associations, and multiple logistic regression models were used for adjusted associations, with all two-sided P<.05 considered statistically significant.

Result(s)

A statistically significant increase was noted in the number of live male births after blastocyst-stage FET compared with that after cleavage-stage FET (51.9% vs. 50.5%). After controlling for potential confounders including age (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.03, 1.08), body mass index (OR, 1.08; 95% CI, 1.04, 1.12), and male factor infertility (OR, 1.06; 95% CI, 1.03, 1.08), the increase in male live births after blastocyst-stage FET remained statistically significant.

Conclusion(s)

In patients undergoing FETs, blastocyst-stage transfers are associated with higher male gender live-birth rates compared with cleavage-stage transfers.

The role of mesenchymal-epithelial transition in endometrial function

BACKGROUND

The human uterine endometrium undergoes significant remodeling and regeneration on a rapid and repeated basis, after parturition, menstruation, and in some cases, injury. The ability of the adult endometrium to undergo cyclic regeneration and differentiation/decidualization is essential for successful human reproduction. Multiple key physiologic functions of the endometrium require the cells of this tissue to transition between mesenchymal and epithelial phenotypes, processes known as mesenchymal-epithelial transition (MET) and epithelial-mesenchymal transition (EMT). Although MET/EMT processes have been widely characterized in embryonic development and in the context of malignancy, mounting evidence demonstrates the importance of MET/EMT in allowing the endometrium the phenotypic and functional flexibility necessary for successful decidualization, regeneration/re-epithelialization and embryo implantation.

OBJECTIVE AND RATIONALE

The objective of this review is to provide a comprehensive summary of the observations concerning MET and EMT and their regulation in physiologic uterine functions, specifically in the context of endometrial regeneration, decidualization and embryo implantation.

SEARCH METHODS

Using variations of the search terms 'mesenchymal-epithelial transition', 'mesenchymal-epithelial transformation', 'epithelial-mesenchymal transition', 'epithelial-mesenchymal transformation', 'uterus', 'endometrial regeneration', 'endometrial decidualization', 'embryo implantation', a search of the published literature between 1970 and 2018 was conducted using the PubMed database. In addition, we searched the reference lists of all publications included in this review for additional relevant original studies.

OUTCOMES

Multiple studies demonstrate that endometrial stromal cells contribute to the regeneration of both the stromal and epithelial cell compartments of the uterus, implicating a role for MET in mechanisms responsible for endometrial regeneration and re-epithelialization. During decidualization, endometrial stromal cells undergo morphologic and functional changes consistent with MET in order to accommodate embryo implantation. Under the influence of estradiol, progesterone and multiple other factors, endometrial stromal fibroblasts acquire epithelioid characteristics, such as expanded cytoplasm and rough endoplasmic reticulum required for greater secretory capacity, rounded nuclei, increased expression of junctional proteins which allow for increased cell-cell communication, and a reorganized actin cytoskeleton. During embryo implantation, in response to both maternal and embryonic-derived signals, the maternal luminal epithelium as well as the decidualized stromal cells acquire the mesenchymal characteristics of increased migration/motility, thus undergoing EMT in order to accommodate the invading trophoblast.

WIDER IMPLICATIONS

Overall, the findings support important roles for MET/EMT in multiple endometrial functions required for successful reproduction. The endometrium may be considered a unique wound healing model, given its ability to repeatedly undergo repair without scarring or loss of function. Future studies to elucidate how MET/EMT mechanisms may contribute to scar-free endometrial repair will have considerable potential to advance studies of wound healing mechanisms in other tissues.

Dynamic Expression of Interleukin-33 and ST2 in the Mouse Reproductive Tract Is Influenced by Superovulation

Interleukin-33 (IL-33) is an IL-1 family cytokine with pleiotropic effects on diverse cell types. Dysregulated IL-33 signaling has been implicated in pregnancy-related disorders, including preeclampsia and recurrent pregnancy loss, and in ovarian function in women undergoing controlled ovarian stimulation for in vitro fertilization. To date, expression of IL-33 and its receptor subunit, ST2, in the female reproductive tract remains poorly characterized. We identify IL-33-expressing oocytes surrounded by ST2-expressing granulosa cells at all stages of follicular development, in addition to IL-33⁺ and ST2⁺ non-endothelial cells in the ovarian stroma and theca layer in ovaries from adult mice. These expression patterns are similar in estrus- and diestrus-stage adults and in pubescent mice, suggesting a role for IL-33 signaling in ovarian function throughout development and in the estrous cycle. In the uterus, we find expression of IL-33 and ST2 in glandular and luminal epithelia during estrus and at the initiation of pregnancy. Uterine IL-33 expression was modulated by the estrous cycle and was reduced in pubescent females. Last, superovulation increases transcripts for IL-33 and the soluble form of ST2 (sST2) in ovaries, and for IL-33 in uteri. Collectively, our findings lay the foundation for studies identifying cell type-specific requirements for IL-33/ST2 signaling in the establishment and maintenance of mouse pregnancy.

Comparison of 2-Hour Oral Glucose Tolerance Test and Hemoglobin A1C in the Identification of Pre-Diabetes in Women with Infertility and Recurrent Pregnancy Loss

RESEARCH QUESTION

Does hemoglobin A1C (HbA1C) predict pre-diabetes (pre-DM) in a population of women with infertility and/or recurrent pregnancy loss (RPL), when considering the 75 g, 2-hour oral glucose tolerance test (2h GTT) as the gold standard?

DESIGN

Retrospective study of 242 patients with infertility or RPL presenting to a university-affiliated reproductive endocrinology and infertility clinic between January 2012 and December 2016 who underwent screening for disorders of glucose metabolism with a 2h GTT. The prevalence of pre-DM as defined by HbA1C 5.7% to 6.4% and 2h GTT values of 140-199 mg/dL, and predictive values of HbA1C for the identification of pre-DM when compared with 2h GTT, were calculated and compared.

RESULTS

Of 242 patients, 188 (77.7%) women had both HbA1C and 2h GTT performed. Of these, 89 (47.3%) tested positive for pre-DM by one or both methods. Of 89 patients, 14 (15.7%) had both an abnormal 2h GTT and an abnormal HbA1C. Only 6 out of 89 (6.7%) patients tested positive for pre-DM by an abnormal 2h GTT in the setting of a normal HbA1C result. Conversely, 69 of these 89 patients (77.5%) tested positive for pre-DM by an abnormal HbA1C in the setting of a normal 2h GTT. The prevalence of pre-DM, as defined by 2h GTT, was 10.6% (20/188) (95% CI, 6.6-16.0), compared with a prevalence of 44.1% (83/188) (95% CI, 36.9-51.6) when pre-DM was defined by HbA1C alone. When the 2h GTT was considered the gold standard for the identification of pre-DM, the negative predictive value (NPV) of HbA1C compared with 2h GTT was 94.3% (95% CI, 88.0-97.9), whereas the positive predictive value (PPV) of HbA1C compared with 2h GTT was only 16.9% (95% CI, 9.5-26.7).

CONCLUSIONS

Although a normal HbA1C was highly predictive of a normal 2h GTT, the two tests demonstrate poor agreement in the identification of pre-DM in women with infertility and/or RPL. Hemoglobin A1C is superior to the 2h GTT as an initial screening test for pre-DM in this population, since it identified a substantial number of women who would otherwise remain undiagnosed in the setting for a normal 2h GTT alone. However, the long-term clinical relevance of an elevated HbA1C in this population needs to be better defined.

Ongoing barriers to immediate postpartum long-acting reversible contraception: a physician survey

Background

Postpartum women are at risk for unintended pregnancy. Access to immediate long-acting reversible contraception (LARC) may help decrease this risk, but it is unclear how many providers in the United States routinely offer this to their patients and what obstacles they face. Our primary objective was to determine the proportion of United States obstetric providers that offer immediate postpartum LARC to their obstetric patients.

Methods

We surveyed practicing Fellows and Junior Fellows of the American College of Obstetricians and Gynecologists (ACOG) about their use of immediate postpartum LARC. These members are demographically representative of ACOG members as a whole and represent all of the ACOG districts. Half of these Fellows were also part of the Collaborative Ambulatory Research Network (CARN), a group of ACOG members who voluntarily participate in research. We asked about their experience with and barriers to immediate placement of intrauterine devices and contraceptive implants after delivery.

Results

There were a total of 108 out of 600 responses (18%). Participants practiced in a total of 36 states and/or US territories and their median age was 52 years. Only 26.9% of providers surveyed offered their patients immediate postpartum LARC, and of these providers, 60.7% work in a university-based practice. There was a statistically significant association between offering immediate postpartum LARC and practice type, with the majority of providers working at a university-based practice (p < 0.001). Multiple obstacles were identified, including cost or reimbursement, device availability, and provider training on device placement in the immediate postpartum period.

Conclusion

The majority of obstetricians surveyed do not offer immediate postpartum long-acting reversible contraception to patients in the United States. This is secondary to multiple obstacles faced by providers.

Improved outcomes after blastocyst-stage frozen-thawed embryo transfers compared with cleavage stage: a Society for Assisted Reproductive Technologies Clinical Outcomes Reporting System study

OBJECTIVE

To investigate whether there is a difference in obstetrical and perinatal outcomes in blastocyst frozen-thawed embryo transfers (FETs) compared with cleavage-stage FET.

DESIGN

A retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

Women undergoing autologous FETs at either the blastocyst stage (n = 118,572) or the cleavage stage (n = 117,619) reported to the Society for Assisted Reproductive Technology in the years 2004-2013.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live birth, gestational age, birth weight, miscarriage.

RESULT(S)

After controlling for confounders, there were a 49% increased odds of live birth after blastocyst-stage FET compared with cleavage-stage FET (odds ratio [OR] = 1.49; 95% confidence interval [CI], 1.44, 1.54). Additionally, blastocyst FET was associated with a 68% (OR = 1.68; 95% CI, 1.63, 1.74) increased odds of clinical pregnancy and an 7% (OR = 0.93; 95% CI, 0.88, 0.92) decreased odds of miscarriage. There was also a 16% increased odds of preterm delivery (OR = 1.16; 95% CI, 1.06, 1.27) after blastocyst FET but no difference in birth weights.

CONCLUSION(S)

In patients undergoing FET, blastocyst-stage transfer is associated with higher live-birth rates when compared with cleavage-stage transfers. Furthermore, perinatal outcomes are similar between the groups.

Metabolic screening in patients with polycystic ovary syndrome is largely underutilized among obstetrician-gynecologists

Women with polycystic ovary syndrome have substantially higher rates of insulin resistance, impaired glucose tolerance, type 2 diabetes, dyslipidemia, and metabolic syndrome when compared with women without the disease. Given the high prevalence of these comorbidities, guidelines issued by the American College of Obstetricians and Gynecologists and the Endocrine Society recommend that all women with polycystic ovary syndrome undergo screening for impaired glucose tolerance and dyslipidemia with a 2 hour 75 g oral glucose tolerance test and fasting lipid profile upon diagnosis and also undergo repeat screening every 2-5 years and every 2 years, respectively. Although a hemoglobin A1C and/or fasting glucose are widely used screening tests for diabetes, both the American College of Obstetricians and Gynecologists and the Endocrine Society preferentially recommend the 2 hour oral glucose tolerance test in women with polycystic ovary syndrome as a superior indicator of impaired glucose tolerance/diabetes mellitus. However, we found that gynecologists underutilize current recommendations for metabolic screening in women with polycystic ovary syndrome. In an online survey study targeting American College of Obstetricians and Gynecologists fellows and junior fellows, 22.3% of respondents would not order any screening test at the initial visit for at least 50% of their patients with polycystic ovary syndrome. The most common tests used to screen for impaired glucose tolerance in women with polycystic ovary syndrome were hemoglobin A1C (51.0%) and fasting glucose (42.7%). Whereas 54.1% would order a fasting lipid profile in at least 50% of their polycystic ovary syndrome patients, only 7% of respondents order a 2 hour oral glucose tolerance test. We therefore call for increased efforts to encourage obstetrician-gynecologists to address metabolic abnormalities in their patients with polycystic ovary syndrome. Such efforts should include education of physicians early in their careers, at the medical student and resident level. Efforts should also include implementation of continuing medical education activities, both locally and at the national level, to improve understanding of the metabolic implications of polycystic ovary syndrome. Electronic medical record systems should be utilized to generate prompts for appropriate screening tests in patients with a diagnosis of polycystic ovary syndrome. Because obstetrician-gynecologists may be the only physicians seen by many polycystic ovary syndrome patients, particularly those in their young reproductive years, such interventions could effectively promote optimal preventative health care and early diagnosis of metabolic comorbidities in these at-risk women.

Endometriosis: a role for stem cells

Endometriosis is a complex gynecologic condition affecting 6-10% of reproductive aged women and is a major cause of chronic pain and infertility. Mechanisms of disease pathogenesis are poorly understood. Considerable evidence supports the existence of a stem cell population in the endometrium which provides a physiologic source of regenerative endometrial cells, and multiple lines of evidence now support a key role for stem cells in the pathogenesis of endometriosis. In addition, new blood vessel formation is critical for the establishment and maintenance of endometriotic implants, a process in which endothelial progenitor cells may play an integral role. These new insights into disease pathogenesis present exciting opportunities to develop targeted and more effective therapeutic options in the management of this common and challenging disease.

Endometrial expression of relaxin and relaxin receptor in endometriosis

Our studies demonstrate significantly lower expression of relaxin and its receptor in ectopic endometriotic tissues than their expression in eutopic endometrium and in endometrium from normal controls. These data suggest that in normal and eutopic endometrium, relaxin may exert a protective effect against endometriosis.

Qualifications of Physicians Performing Hysterectomy: The Study of Women's Health Across the Nation

The objective of this study was to evaluate whether physicians performing hysterectomy on participants of the Study of Women's Health Across the Nation (SWAN) are adequately trained to perform this procedure. A multicenter longitudinal study of 3302 women aged 42 to 52 was conducted over 9 years of follow-up. Of the 238 women reporting hysterectomy within the United States, 165 were verified via medical record review. Information regarding training background and board certification status of the physicians performing these hysterectomies was obtained from the American Board of Medical Specialists. Complications of hysterectomy were abstracted from patients' medical records. Of the 165 physicians, 163 (98.8%) obtained board certification and 139 (84.2%) obtained their medical degrees in the United States. Ninety-eight percent of the physicians completed a residency in obstetrics and gynecology. Intra- and postoperative complications were exceedingly low. Physicians performing hysterectomies on participants of SWAN appear adequately trained to carry out this commonly performed procedure.

Relaxin in endometriosis

Endometriosis is an important contributing factor to chronic pelvic pain and infertility. Matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) have each been implicated in the establishment of endometriotic lesions. Since relaxin regulates the expression of MMPs and VEGF in the endometrium, we tested the hypothesis that relaxin plays a role in endometriosis by comparing the expression of relaxin mRNA and its LGR7 (RXFP1) receptor mRNA in normal human endometrium to those in samples from patients with endometriosis.

Low ectopic pregnancy rates after in vitro fertilization: do practice habits matter?

In a 6-year review of ectopic pregnancies (EPs) after fresh and frozen embryo transfers in IVF cycles conducted at a large university-based program, we report an overall 0.9% rate of EP that seems to have increased with the programmatic shift to routine blastocyst transfer, but remains lower than nationally reported rates. Aggressive management of tubal disease may contribute to low rates of EP, whereas blastocyst transfer may increase the rate.