Embryo implantation

Decidual macrophages (dMϕs) play critical roles in regulation of immune-microhomeostasis at maternal-fetal interface during pregnancy, but the underlying molecular mechanisms are still unclear. In this study, it was found that litter size and fetal weight were significantly reduced, whereas the rate of embryo resorption was increased in miR-3074-5p knock-in (3074-KI) pregnant mice, compared to that of wild-type (WT) pregnant mice. Plasma levels of pro-inflammatory cytokines in 3074-KI pregnant mice were also significantly elevated compared to WT pregnant mice at GD7...

OBJECTIVE: This study investigated the metabolic status of the spent culture media from embryos of patients with repeated implantation failure (RIF) undergoing in vitro fertilization-intracytoplasmic sperm injection cycles in comparison with the embryos from healthy fertile women. METHODS: Metabolite levels in spent culture media were assessed and compared between embryos from RIF patients (n=35) and oocyte donors as controls (n=15). Protein levels of insulin-like growth factor 1 (IGF-1) were determined using Western blotting...

OBJECTIVE: This study aims to investigate the effect of diminished ovarian reserve (DOR) on the clinical outcomes and maternal and infant safety of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) procedures in young women aged ≤ 35 years. METHODS: A retrospective cohort study was performed to analyze the clinical data of 4,203 infertile women aged ≤ 35 years who underwent fresh embryo transfer (ET) in IVF/ICSI cycles...

Early embryonic development is a finely orchestrated process that requires precise regulation of gene expression coordinated with morphogenetic events. TATA-box binding protein-associated factors (TAFs), integral components of transcription initiation coactivators like TFIID and SAGA, play a crucial role in this intricate process. Here we show that disruptions in TAF5, TAF12 and TAF13 individually lead to embryonic lethality in the mouse, resulting in overlapping yet distinct phenotypes. Taf5 and Taf12 mutant embryos exhibited a failure to implant post-blastocyst formation, and Taf5 mutants have aberrant lineage specification within the inner cell mass...

Monochorionic twinning of human embryos increases the risk of complications during pregnancy. The rarity of such twinning events, combined with ethical constraints in human embryo research, makes investigating the mechanisms behind twinning practically infeasible. As a result, there is a significant knowledge gap regarding the origins and early phenotypic presentation of monochorionic twin embryos. In this study, a microthermoformed-based microwell screening platform is used to identify conditions that efficiently induce monochorionic twins in human stem cell-based blastocyst models, termed "twin blastoids"...

BACKGROUND: this study aims to assess the effect of embryo transfer (ET) performance parameters of a technical nature on IVF outcome. METHODS: A total of 1417 ETs from a single IVF center were included in this prospective observational study. The parameters investigated were as follows: the presence of cervical mucus post catheter withdrawal, the presence of blood, catheter reload, the employment of a tenaculum and stylet, catheter resistance as experienced by the physician and patient discomfort...

BACKGROUND: Euploid blastocyst implantation failure may result from embryonic factors undetectable by preimplantation genetic testing for aneuploidy (PGT-A); however, various nonembryonic factors can also intricately interfere with implantation. This review seeks to clarify evidence-based testing and treatments for implantation failure after euploid embryo transfer. METHODS: We conducted a review of the literature on implantation failure after euploid embryo transfer or multiple embryo transfer cycles, which mainly included systematic reviews and meta-analyses...

OBJECTIVE: To assess how obesity, normal weight (NW) versus overweight/obese (OW/OB), impacts platelet-rich plasma's (PRP) effectiveness during in vitro fertilization and how obesity affects platelets during the menstrual cycle. METHODS: Endometrial mean thickness (EMT), embryo implantation, and clinical pregnancy were assessed using a self-controlled retrospective study that enrolled 59 patients with two failed cycles and treated with autologous PRP (three-dose scheme)...

Benzo(a)pyrene [B(a)P] is an environmental endocrine disruptor with reproductive toxicity. The corpus luteum (CL) of the ovary plays an important role in embryo implantation and pregnancy maintenance. Our previous studies have shown that B(a)P exposure affects embryo implantation and endometrial decidualization in mouse, but its effects and mechanisms on CL function remain unclear. In this study, we explore the mechanism of ovarian toxicity of B(a)P using a pregnant mouse model and an in vitro model of human ovarian granulosa cells (GCs) KGN...

Air pollution (AP) is one of the main recent concerns in reproductive healthy due to its potential to promote negative outcomes during pregnancy and male and female fertility. Several studies have demonstrated that AP exposure has been linked to increased embryonic implantation failures, alterations in embryonic, fetal and placental development. For a well-succeeded implantation, both competent blastocyst and receptive endometrium are required. Based on the lack of data about the effect of AP in endometrial receptivity, this study aimed to evaluate he particulate matter (PM) exposure impact on uterine receptive markers in mice and associate the alterations to increased implantation failures due to AP...

Hyaluronic acid (HA) plays a prominent role in various aspects of reproductive biology and assisted reproductive technologies (ART). This review describes the multifaceted influence of HA, ranging from primordial germ cell migration, ovarian follicle development, and ovulation in females to sperm structure, physiology, motility, and capacitation in males. In addition, HA also plays an important role in fertilization and promotes embryo implantation by mediating cellular adhesion and communication within the uterus...

OBJECTIVE: To compare the morphokinetic pattern of human embryos originating from vitrified oocytes with those derived from freshly collected oocytes in oocyte donation cycles. DESIGN: A retrospective observational study SETTING: Embryolab Fertility Clinic, Embryology lab, Thessaloniki, Greece PATIENT(S): The study included embryos from 421 vitrified oocytes from 58 oocyte donation cycles and 196 fresh oocytes from 23 oocyte donation cycles. INTERVENTION(S): None MAIN OUTCOME MEASURE(S): Key time parameters, dynamic events, fertilization rate, degeneration rate, cleavage rate, blastocyst rate, pregnancy rate, clinical pregnancy rate, implantation rate and live birth rate...

Basement membranes (BMs) are sheet-like structures of extracellular matrix (ECM) that provide structural support for many tissues and play a central role in signaling. They are key regulators of cell behavior and tissue functions, and defects in their assembly or composition are involved in numerous human diseases. Due to the differences between human and animal embryogenesis, ethical concerns, legal constraints, the scarcity of human tissue material, and the inaccessibility of the in vivo condition, BM regulation during human embryo development has remained elusive...

PURPOSE: Nifedipine is a calcium channel blocker with smooth muscle relaxing properties. This study set out to investigate the efficacy of nifedipine administered orally before embryo transfer (ET) on the improvement of the intracytoplasmic sperm injection (ICSI) outcome. This randomized, double-blind, comparator-controlled, was carried out between 2019 and 2020 in the infertility center of Babol, Iran. 200 women candidates for ICSI and recipients of frozen-thawed ET aged 18-40 years were randomly assigned in the ratio 1:1 to an intervention group that received nifedipine 20 mg tablets orally 30 min before ET (n = 100) or to a group of placebo (n = 100)...

OBJECTIVE: Despite its widespread use, in vitro fertilization (IVF) outcomes are challenged by implantation failure, largely due to factors such as embryo quality and endometrial receptivity. In this study, we investigated the clinical effect of office hysteroscopy (OH) on the subsequent frozen-thawed embryo transfer (FET) in infertile women who experienced a failed IVF-embryo transfer (IVF-ET) cycle. METHODS: We included 577 infertile women who underwent OH because of a history of failed ET between October 2019 and September 2021...

Transforming growth factor-beta (TGF-β) plays a critical role in regulating trophoblast invasion and proliferation. Growth differentiation factor-8 (GDF-8) is a member of the TGF-β superfamily and is categorized as a myostatin subtype. It is primarily a secreted protein synthesized in skeletal muscle cells. It is expressed in the placenta, reproductive tissues, and cells. In this study, we investigated the role of GDF-8 in the development and hatching rate of bovine embryos. We noted a notable elevation ( p < 0...

Inadequate endometrial receptivity often results in embryo implantation failure and miscarriage. Human chorionic gonadotropin (hCG) is a key signaling molecule secreted during early embryonic development, which regulates embryonic maternal interface signaling and promotes embryo implantation. This study aimed to examine the impact of hCG on endometrial receptivity and its underlying mechanisms. An exploratory study was designed, and endometrial samples were obtained from women diagnosed with simple tubal infertility or male factor infertile (n = 12) and recurrent implantation failure (RIF, n = 10)...

Transcription factors (TFs) play important roles in early embryonic development, but factors regulating TF action, relationships in signaling cascade, genome-wide localizations, and impacts on cell fate transitions during this process have not been clearly elucidated. In this study, we used uliCUT&RUN-seq to delineate a TFAP2C-centered regulatory network, showing that it involves promoter-enhancer interactions and regulates TEAD4 and KLF5 function to mediate cell polarization. Notably, we found that maternal retinoic acid metabolism regulates TFAP2C expression and function by inducing the active demethylation of SINEs, indicating that the RARG-TFAP2C-TEAD4/KLF5 axis connects the maternal-to-zygotic transition to polarization...

PURPOSE OF REVIEW: Endometrial thickness has been regarded a predictor of success in assisted reproductive technology cycles and it seems a common practice to cancel embryo transfer when it is below a cut-off. However, various cut-offs have been proposed without a causal relationship between endometrial thickness and embryo implantation being established, casting doubt on the current dogma. RECENT FINDINGS: Methodological limitations of the available studies on endometrial thickness are increasingly recognized and better designed studies do not demonstrate a cut-off value which requires cancelling an embryo transfer...

BACKGROUND: Extracellular vesicles (EVs) present in oviductal (OF) and uterine fluid (UF) have been shown to enhance bovine embryo quality during in vitro culture by reducing lipid contents and modulating lipid metabolism-related genes (LMGs), while also influencing cell proliferation, suggesting their involvement on the regulation of different biological pathways. The regulation of signaling pathways related to cell differentiation, proliferation, and metabolism is crucial for early embryo development and can determine the success or failure of the pregnancy...