Reproductive medicine and biology

PURPOSE: To identify the specific risk factors associated with unexplained infertility (UI) among infertile couples. METHODS: We conducted a retrospective cohort study analyzing UI risk factors, focusing on 5465 infertile couples who compl…

PURPOSE: The follicular fluid (FF) microenvironment critically influences oocyte development, with Anti-Müllerian Hormone (AMH) serving as a primary marker of ovarian reserve. This exploratory pilot study investigates the biochemical and pr…

BACKGROUND: Endometriosis is often diagnosed late due to a lack of noninvasive diagnostic tools and the varied presentation of its symptoms. Identifying risk factors for endometriosis is crucial for reducing diagnosis delays, mitigating the…

PURPOSE: To evaluate the association between hysteroscopic treatment of cesarean scar disorder (CSDi), clinical improvement, and changes in the endometrial microbiome, as this remains unclear. METHODS: This prospective observational study …

BACKGROUND: Thyroid autoimmunity (TAI) is prevalent among women of reproductive age and has been associated with impaired fertility; however, its effects on ovarian reserve and infertility treatment outcomes remain controversial. METHODS: …

This paper critically evaluates Sekiguchi et al.'s study of vaginal progesterone dose, serum progesterone thresholds, and reproductive outcomes in hormone replacement therapy frozen embryo transfer (HRT-FET) cycles. The study conflates desc…

[This corrects the article DOI: 10.1002/rmb2.70048.].

BACKGROUND: With the increase in the number of patients with infertility, the number of patients requiring in vitro fertilization and embryo transfer (IVF-ET) is also increasing. No established method exists for predicting pregnancy rates u…

PURPOSE: To assess whether autoimmune thyroiditis is associated with obstetric, perinatal, and fetal complications in a nationally representative population of pregnant women. METHODS: This retrospective study utilized data from the U.S. N…

ObjectiveSince 2023, our university hospital has incorporated hyaluronan-enriched transfer medium (HETM) into all frozen-thawed embryo transfers (FETs). This study aimed to evaluate whether HETM improved clinical pregnancy rates in FET, par…

PURPOSE: This case-control study investigated whether ovarian endometriosis is associated with altered estrogen metabolism and gut or urogenital microbiota by analyzing enzyme activity, bacterial composition, and variations of estrogen meta…

BACKGROUND: Recurrent implantation failure (RIF) is an infertility condition in which uterine factors remain difficult to diagnose and treat. Recent studies implicate the endometrial microbiome in implantation. METHODS: This clinically ori…

PURPOSE: To evaluate changes in immunoexpression of proteins involved in epigenetic regulation in the uterus in female ICR mice following neonatal exposure to tamoxifen. METHODS: Thirty-two neonatal mice were randomly assigned to 2 groups:…

PURPOSE: To determine the prevalence and clinical significance of arcuate uterus among infertile women using three-dimensional transvaginal ultrasound (3D-TVUS). METHODS: This retrospective cohort included 327 women evaluated for infertili…

PURPOSE: Decidualization of endometrial stromal cells involves significant morphological and functional changes in which alpha-smooth muscle actin (αSMA) expression decreases. Meflin, a glycosylphosphatidylinositol-anchored protein, suppres…

BACKGROUND: Endometriosis is increasingly recognized as a disorder of impaired reproductive immune tolerance rather than solely an endocrine disease. Although previous studies have reported inconsistent findings regarding the number of regu…

PURPOSE: This study investigated whether perinatal complications in assisted reproductive technology are attributable to embryo cryopreservation or the specific endometrial preparation method, comparing Fresh Embryo Transfer (Fresh ET), Nat…

PURPOSE: This study examined whether the incidence of retained products of conception (RPOC) differs between hormone replacement cycles (HRC) and natural ovulation cycles (NC) in frozen-thawed embryo transfer (FET) pregnancies. METHODS: We…

PURPOSE: This study aimed to develop international expert consensus statements on chronic endometritis (CE) through a comprehensive literature review of existing evidence and a modified Delphi approach. METHODS: Ten panelists of the Japan …

PURPOSE: In women with unilateral endometriosis, how do ovarian endometriomas and their inflammatory content affect oocyte and embryo quality in affected versus healthy ovaries, and what is the impact on ART outcomes? METHODS: This study, …

PURPOSE: To evaluate the role of optimizing the maternal microbiome in improving pregnancy outcomes, focusing on preconception and early gestation, and to propose practical diagnostic and preventive strategies, particularly in low- and midd…

PURPOSE: This study examined whether the application of public insurance on assisted reproductive technology in Japan was associated with changes in the incidence of multiple blastocyst transfer (MBT) and subsequent multiple pregnancies (MP…

PURPOSE: To clarify the efficacy and safety of the estetrol 15 mg/drospirenone 3 mg combination among Japanese women with adenomyosis by post hoc analyses of a previous randomized clinical study. METHODS: Post hoc analyses were performed u…

PurposeTo estimate the prevalence and correlates of low serum 25-hydroxyvitamin D [25(OH)D] among women attending infertility clinics in Japan.MethodsWe conducted a multicenter cross-sectional study of 17 261 women with measured 25(OH)D. De…