Women's biopsychosocial experiences following embryo transfer: A qualitative study.

Progesterone plays a pivotal role in implantation and ongoing pregnancy. In the context of assisted reproductive technology (ART), and in particular frozen embryo transfer (FET), increasing evidence suggests that serum progesterone levels strongly influence reproductive outcomes. This review summarizes the latest findings regarding the optimal range of serum progesterone concentrations and their implications across different endometrial preparation protocols. Observational and interventional studies have consistently shown that suboptimal mid-luteal serum progesterone levels are associated with lower implantation and live birth rates in FET cycles. The need for exogenous supplementation varies according to the type of endometrial preparation, with hormone replacement therapy cycles being particularly sensitive to inadequate progesterone exposure. Emerging data support the concept of individualized luteal support, including serum-guided adjustments or alternative routes of administration in cases of suboptimal serum progesterone levels. Adequate serum progesterone concentrations are critical for optimizing outcomes after FET. Evidence supports a paradigm shift from empirical supplementation to precision medicine approaches based on serum thresholds and patient characteristics. Future research should aim to define universally accepted cutoff values, clarify the role of endometrial versus systemic progesterone, and refine strategies for tailoring luteal phase support in ART.

To investigate the associations between maternal body mass index (BMI) and pregnancy outcomes in single euploid frozen embryo transfer cycles. This single-center retrospective study analysed 4235 single euploid blastocyst transfer (SEBT) cycles performed between January 2018 and December 2024. Clinical outcomes were analysed using generalized estimating equations to assess the impact of BMI categories (underweight, normal, overweight, obese). Restricted cubic splines and Random forest models were employed to characterize the association between continuous BMI and clinical outcomes. Clinical pregnancy rates were significantly lower in underweight (34.6%; aOR 0.66, p = 0.001) and obese women (37.5%; aOR 0.69, p = 0.014) than in normal-weight women (44.5%), whereas no significant difference was observed in the overweight group. Obesity was associated with increased odds of clinical miscarriage (aOR 2.17, p = 0.006) and preterm birth (aOR 3.05, p = 0.002), while underweight status had no significant effect on either outcome. Accordingly, live birth rates were reduced across all abnormal BMI categories, with the strongest effect observed in obese women (aOR 0.58, p < 0.001), followed by underweight (aOR 0.69, p = 0.006) and overweight women (aOR 0.85, p = 0.048). GEE-based restricted cubic spline analyses showed significant inverted U-shaped associations of maternal BMI with clinical pregnancy and live birth, with peak odds at BMI 21.9 kg/m2 and 21.5 kg/m2, respectively (clinical pregnancy: p for trend = 0.001, p for non-linearity < 0.001; live birth: p for trend < 0.001, p for non-linearity = 0.005). A similar single-peaked pattern was observed in the random forest models and remained broadly consistent across age groups and blastocyst-quality strata. Maternal BMI exerts a stage-specific, non-linear influence on reproductive outcomes in euploid embryo transfers. Underweight status predominantly hinders pregnancy establishment, whereas obesity exerts a broader adverse effect across both pregnancy establishment and subsequent continuation. These findings support individualized, stage-informed counselling and highlight preconception weight optimization as a clinically actionable target to improve overall treatment success.

Cell exclusion (CE) is a morphological phenomenon observed and characterized relative to embryo morulation, yet its implications for reproductive competence seem heterogeneous. This study investigated whether variability in reproductive success among CE-containing (CE+) embryos could be attributed to differences in the timing and physical extent of cell exclusion, cleavage-stage morphology and morphokinetics. A total of 698 embryos cultured in time-lapse incubators, across two independent fertility clinics, were retrospectively analysed. Embryos were assessed for the presence of CE (CE+, n = 155) prior to fresh embryo transfer and stratified according to the cleavage stage at which excluded cell(s) first appeared. Reproductive success varied markedly across CE+ subgroups, where exclusions at the 9-cell stage (CE+9) resulted in the highest proportions of FHB and LB, comparable to embryos without CE (CE-, n = 543). Exclusions at the 6-cell (CE+6), 8-cell (CE+8), 3-cell (CE+3) stages, and combination (CE+C) exclusions were associated with the poorest outcomes following logistic regression analysis. Neither the number of excluded cells nor the relative surface area occupied by exclusions (%SA) was shown to predict reproductive success, however correlation analysis revealed associations between %SA and various morphokinetic parameters. Routine embryo morphology annotations did not vary between CE+ subgroups. These findings demonstrate that the developmental stage of CE, rather than the extent of exclusion, may represent the primary driver of heterogeneity in reproductive competence among CE+ embryos.

Oestradiol concentration on ovulatory trigger day and live births in letrozole-stimulated frozen embryo transfer cycles.

Revisiting embryo selection: inner cell mass outweighs the trophectoderm in predicting live birth in single frozen blastocyst transfers.

Myomectomy for intramural fibroids prior to invitro fertilization/intracytoplasmic sperm injection cycles, a conundrum: Systematic review and meta-analysis.

Embryo warming using an ultrafast protocol: perinatal outcomes from 1020 births from a single UK IVF centre.

Clinical outcomes of combining recombinant follicle-stimulating hormone (rFSH) with highly purified human menopausal gonadotropin (HP-hMG) versus rFSH alone were compared in patients undergoing in vitro fertilization in a real-world setting. This retrospective cohort study analyzed patients who underwent ovarian stimulation with rFSH or rFSH + HP-hMG following a gonadotropin-releasing hormone antagonist protocol, followed by fresh or frozen embryo transfer (ET) at two centers in Korea. A total of 1,028 women were included: 329 underwent fresh ET (rFSH: n = 78; rFSH + HP-hMG: n = 251) and 699 underwent frozen ET (rFSH: n = 250; rFSH + HP-hMG: n = 449). Across both fresh and frozen ET group, patients receiving rFSH + HP-hMG were older and had lower anti-Müllerian hormone levels and antral follicle counts. Despite fewer oocytes retrieved in rFSH + HP-hMG group (fresh: 9.5 vs. 11.0; frozen: 16.3 vs. 20.6, both p < 0.05), metaphase II oocyte rates and clinical pregnancy rates were comparable (fresh: 44.6 vs. 43.6%; frozen: 58.4 vs. 56.8%, both p > 0.05). Notably, ovarian hyperstimulation syndrome incidence was significantly lower in rFSH + HP-hMG group among frozen ET patients (6.9 vs. 13.2%, p < 0.01). These findings suggest that rFSH + HP-hMG achieves comparable clinical outcomes to rFSH alone despite less favorable prognostic characteristics that could affect clinical outcome, supporting its role as a clinically acceptable alternative stimulation option in routine practice.

To evaluate whether artificial endometrial preparation using hormone replacement therapy (HRT) influences clinical and neonatal outcomes compared with modified natural cycles (mNC) in single euploid vitrified-warmed blastocyst transfers. This retrospective cohort study analyzed single euploid vitrified-warmed blastocyst transfers performed at a single IVF center over an 11-year period. Endometrial preparation was conducted either through HRT or mNC. Clinical and neonatal outcomes were compared between groups. Statistical analyses included multivariable logistic regression models, adjusted for relevant confounders, with generalized estimating equations to account for repeated embryo transfers (ETs) within patients. A total of 3507 ETs were conducted in 2257 patients. Mean age was 37.5 ± 3.2years at oocyte pick-up and 37.8 ± 3.3years at ET. HRT was associated with a higher miscarriage rate (N = 167/1034, 16.2% vs N = 70/700, 10%; OR 1.72, 95% CI 1.27-2.33) and a lower live birth rate (N = 867/2129, 40.7% vs N = 630/1378, 45.7%; OR 0.83, 95% CI 0.72-0.96) than mNC. Additionally, HRT was associated with a higher prevalence of large for gestational age newborns. mNC endometrial preparation may show some clinical benefit compared to HRT. The latter remains necessary in specific cases, such as hypothalamic amenorrhea (excluded in this study), but mNC protocols should be preferred whenever possible. Randomized controlled trials in Preimplantation Genetic Testing for Aneuploidy (PGT-A) cycles are essential to confirm these findings.

To examine the association between ambient temperature and pregnancy outcomes of in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) participants. We included 10,988 infertile participants who underwent their first IVF/ICSI-ET at a major assisted reproduction specialist hospital in Chengdu, China, between 2019 and 2022. Ambient temperature was assessed using daily mean temperatures from the European Centre for Medium-Range Weather Forecasts Reanalysis v5 (ERA5) dataset, matched to the women's residential addresses, and eight exposure periods were defined based on key stages of IVF treatment. We used a generalized linear model to explore the association between ambient temperature and clinical pregnancy and live birth, constructing dose-response curves to examine non-linearity. Among the participants, 5,805 (52.83%) achieved clinical pregnancy, 4,979 (45.31%) further achieved live birth. We observed that both low- and high-temperature exposures significantly influence pregnancy outcomes. Specifically, during the clinical pregnancy confirmation period (from serum hCG test to ultrasound test), higher temperatures during cold weather were positively associated with clinical pregnancy rate [adjusted odds ratio (aOR) = 1.017, 95% confidence interval (95% CI) 1.005, 1.030]. During hot weather, increased temperatures were negatively associated with live birth rate. This association was observed during the ovarian stimulation phase (from gonadotropin start to oocyte retrieval) (aOR = 0.887, 95% CI 0.803, 0.980), pregnancy period (from ultrasound test to delivery outcome) (aOR = 0.962, 95% CI 0.950, 0.974), and throughout the entire pregnancy period (from serum hCG test to delivery outcome) (aOR = 0.921, 95% CI 0.909, 0.934). Restricted cubic spline curve results indicated significant nonlinear associations between hot weather during pregnancy and the entire pregnancy period and live birth. Our study reveals a significant association between IVF treatment outcomes and extreme environmental temperatures, with critical thresholds identified. Exposure to high temperatures during pregnancy (exceeding 21.1 ℃ and 20.8 ℃, respectively) was associated with reduced live birth rates, demonstrating the stage specificity of temperature risks.

This review synthesizes current evidence on how endometrial polyps, leiomyomas, adenomyosis, and endometriosis influence endometrial receptivity, emphasizing phenotype-specific effects, molecular mechanisms, and implications for embryo transfer outcomes. Impaired endometrial receptivity, when present, is mediated by a limited set of convergent pathways, including Homeobox gene (HOX) A10/HOXA11 suppression, inflammatory cytokine dysregulation, and progesterone resistance. Leiomyomas and adenomyosis alter decidualization through paracrine signaling, including TGF-β-mediated pathways. Adenomyosis is consistently associated with defective decidualization and altered estrogen-progesterone signaling. Endometriosis alone appears to have limited direct effects on receptivity, and many studies are confounded by unrecognized coexisting adenomyosis. Clinical benefit from polypectomy and myomectomy is phenotype-dependent, with the strongest support for submucous fibroids and selected polyps. Commercial receptivity assays (e.g. BCL6-based testing) remain insufficiently validated to guide clinical decision-making. These pathologies do not uniformly impair endometrial receptivity. When impairment occurs, it is phenotype-specific and mediated through shared molecular pathways. Current evidence supports targeted surgical intervention in selected phenotypes, but at present, there are no available tests, such as those assessing relevant endometrial expressions, to guide more specific case selection. Future work should link phenotype-specific treatment to restoration of validated molecular markers and live birth outcomes.

First Healthy Live Birth Achieved Through Assisted Reproductive Technologies in Türkiye After Lung Transplantation: A Case Report.

Endometriosis and adenomyosis are estrogen-dependent inflammatory conditions frequently associated with impaired fertility. Although progesterone resistance at the tissue level is well documented, it remains unclear whether these conditions are associated with altered systemic progesterone exposure during frozen-thawed embryo transfer (FET) cycles and whether higher circulating progesterone levels are required to achieve successful reproductive outcomes. To evaluate mean serum progesterone levels on the day of FET in women with endometriosis and/or adenomyosis compared with unaffected controls, and to explore potential differences according to endometrial preparation protocol and pregnancy outcome. This retrospective single-center cohort study included 1,927 women undergoing their first single-blastocyst FET between June 2020 and December 2023. FET cycles were performed using hormone replacement therapy (HRT) or modified natural cycle (mNC) protocols. Serum progesterone was measured on the day of embryo transfer. Women were categorized into three groups: endometriosis, adenomyosis, and unaffected controls. Analyses were stratified by FET protocol. Mean serum progesterone concentrations differed between HRT-FET and mNC-FET cycles and were therefore analyzed separately. In both protocols, progesterone levels were comparable between women with endometriosis or adenomyosis and unaffected controls, and live birth rates did not differ across diagnostic groups or between endometrial preparation strategies within each group. Among women with adenomyosis undergoing HRT-FET, those achieving live birth showed higher mean progesterone levels compared with those who had no live birth (β = 1.76, 95% CI 0.30-3.22, p-value = 0.018), whereas no significant association was observed in mNC-FET cycles. Progesterone concentrations did not differ according to reproductive outcome in women with endometriosis or in unaffected controls. Women with endometriosis or adenomyosis do not exhibit reduced mean serum progesterone levels at the time of FET compared with unaffected controls, and do not appear to require higher systemic progesterone exposure to achieve live birth. However, lower progesterone levels among women with adenomyosis who did not achieve a live birth, particularly in HRT-FET cycles, suggest that a subset of patients may exhibit different progesterone dynamics, warranting further investigation. Prospective studies are needed to determine whether tailored luteal phase hormonal support strategies may be beneficial in this population.

Mosaicism, the presence of both euploid and aneuploid cell lines within a single embryo, presents a significant challenge in assisted reproduction. While emerging data support the transfer of mosaic embryos in the absence of euploid alternatives, clinical outcomes are variable. Evidence suggests a correlation between the degree of mosaicism and developmental potential, with higher-level mosaicism generally associated with less favorable outcomes, including reduced implantation and higher miscarriage rates. We present the case of an uneventful liveborn delivery resulting from the intentional transfer of an embryo classified via preimplantation genetic testing for aneuploidy (PGT-A), as exhibiting very high-level mosaicism (75%). This transfer was performed due to the absence of any euploid embryos available for selection. This case demonstrates that even embryos with a very high degree of chromosomal mosaicism can result in healthy, ongoing pregnancies and live births. It contributes to the growing body of evidence on the clinical potential of mosaic embryos and highlights the necessity for nuanced, patient-specific counseling when considering such transfers.

Assisted reproductive technologies (ART) have been proven to be associated with the increased risk of pregnancy complications such as gestational hypertension and neonatal disorders, which may have negative effects on offspring's health. However, insufficient evidence exists to evaluate the intellectual performance of children born after ART. Thus, the aim of our study is to evaluate the intellectual performance of children born after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). This prospective cohort study was performed at the Center for Reproductive Medicine, Shandong University. Children conceived by artificial insemination with donor sperm (AID) were enrolled as controls. Age and sex of children, maternal age, family income and education of parent and caregiver were used for propensity score matching in a ratio of 2:1. The total population consisted of 639 singletons aged 6-14 years old (426 in IVF/ICSI group, and 213 in AID group). Wechsler Intelligence Scale for Children Fourth Edition (WISC-IV) Questionnaire was used to evaluate the intellectual performance. Generalized estimating equation was performed to compare the WISC-IV scores between two groups. The result of sensitivity analysis from the first WISC-IV test of children remains the same. The WISC-IV Questionnaire scores, the verbal comprehension Index (VCI) and the perceptual reasoning Index (PRI) were all comparable between IVF/ICSI and AID groups. But scores of the block design and digit span were both lower in IVF/ICSI group [block design: 12.6 ± 4.4 vs. 13.6 ± 6.5, adjusted β (95%CI): -1.13 (-2.17, -0.08); digit span: 11.2 ± 3.5 vs. 12.2 ± 4.2, adjusted β (95%CI): -1.07 (-1.75, -0.39)]. The results of subgroup analysis showed that the scores of digit span were lower in both fresh embryo transfer (fresh ET) and frozen embryo transfer (frozen ET) groups compared with AID group [fresh ET: adjusted β (95%CI): -0.97 (-1.69, -0.24); frozen ET: -1.30 (-2.12, -0.49)], and the score of block design, matrix reasoning, coding were significantly lower in frozen ET group. The scores of digit span were lower in both IVF and ICSI groups [IVF: adjusted β (95%CI): -1.15 (-1.87, -0.43); ICSI: -0.97 (-1.83, -0.11)], and the scores of block design, matrix reasoning were significantly lower in IVF group. Children born after IVF/ICSI have similar FSI scores compared with offspring conceived by AID, but had a poor performance on block design and digit span. These conclusions still need to be confirmed in naturally conceived (NC) children.

Embryo cryopreservation through vitrification is widely used to store surplus embryos for future transfer. Traditional multi-step warming methods are both time-consuming and costly. This study evaluates the clinical outcomes and the effectiveness of a novel direct warming method for frozen embryo transfer (FET) in comparison to the conventional multi-step method. This is a pragmatic, two-arm, double-blinded randomized controlled trial (RCT) comparing the new direct warming method with the conventional multi-step method. Participants undergoing FET will be randomly assigned to either the direct warming method or the conventional warming protocol. The primary outcomes are the clinical pregnancy rate (CPR), ongoing pregnancy rate (OPR), the live birth rate (LBR), miscarriage rate, and cost-effectiveness. Secondary outcomes include identifying clinical differences among various brands of warming media, embryo storage devices, and embryo culture media through subgroup analyses. A sample size of 578 participants is planned, allowing for a 5% loss to follow-up. Preliminary studies have shown that the direct warming method offers comparable or slightly higher live birth rates than conventional methods. Moreover, it significantly reduces thawing time and associated costs, offering a faster, cost-effective option for FET. This trial has the potential to improve accessibility to ART by reducing procedural costs and increasing efficiency without compromising clinical outcomes. ClinicalTrials.gov NCT06741748. Registered on 19 November 2024.

Abnormal pronuclear formation, including five pronuclei (5PN), is generally considered indicative of abnormal fertilization (e.g., polyspermy or failure of polar body extrusion) and leads to routine embryo discard in many IVF programs. However, emerging evidence suggests that a minority of embryos with atypical pronuclear patterns may develop into a blastocyst and present diploid constitution after genetic testing, challenging the assumption that abnormal pronuclear morphology invariably predicts non-viability. We report a rare case in which a 5PN zygote developed into a morphologically high-quality blastocyst was confirmed euploid-diploid by PGT-A, transferred in a subsequent frozen embryo transfer cycle, and resulted in the live birth of a healthy child. This case adds to the limited but growing evidence that embryos with atypical pronuclear presentation may retain reproductive potential when development on time-lapse appears coherent and validated genetic testing confirms diploidy and euploidy, supported by appropriate patient counseling and informed consent.

Chronic endometritis (CE) has been associated with implantation failure and recurrent reproductive failure. Antibiotic therapy is widely used as a first-line treatment for CE, and previous studies have suggested that successful treatment may improve subsequent reproductive outcomes. A total of 6,371 women who experienced their first implantation failure after IVF/ICSI treatment at Henan Provincial People's Hospital between May 2019 and December 2023 were initially identified. Following the application of stringent exclusion criteria, 2,555 frozen-thawed embryo transfer (FET) cycles were ultimately included in this retrospective cohort study. This study aimed to evaluate the association between antibiotic treatment and pregnancy outcomes in subsequent FET cycles among women with first implantation failure. Among the 2,555 women included in the analysis, 383 (15.0%) were diagnosed with CE at the initial assessment, whereas 2,172 had no evidence of CE (NCE group). After one course of oral antibiotic therapy, 309 were classified as having cured CE (CCE group) and 74 as having persistent CE (PCE group) on repeat histological evaluation. Analysis of pregnancy outcomes in the subsequent FET cycles revealed significant differences in both the live birth rate (LBR) and clinical pregnancy rate (CPR) among the three groups, with the highest rates observed in the CCE group and the lowest in the PCE group. In women with first implantation failure, cured CE after antibiotic treatment was associated with improved reproductive outcomes, whereas persistent CE remained associated with poorer subsequent outcomes; however, these associations should be interpreted cautiously given the retrospective design and the possibility of residual confounding. Our findings suggest that post-treatment reassessment to confirm histological resolution may be clinically informative in the management of CE.

Single embryo transfer (SET) is considered the most effective method for reducing multiple pregnancies in assisted reproduction. Nevertheless, couples in Germany often opt for double embryo transfer (DET) in the hope of achieving a higher success rate. The aim of this study was to evaluate the effectiveness of two consecutive SETs compared to one DET. We conducted a retrospective analysis of data from 133 German fertility clinics. Treatment cycles between January 2017 and December 2022 were analyzed. The parameters examined were the clinical pregnancy rate (CPR) and the live birth rate (LBR), the type of birth (single or multiple), the number of children born, the percentage of premature births, and birth weight. The rates of clinical pregnancy and live birth after fresh transfer were higher after DET than after SET (49.2% vs. 45.1% and 38.4% vs. 35.2%, respectively), but more women achieved a live birth with two SETs than with one DET (5111 of 11 205 [45.6%] vs. 4304 of 11 205 [38.4%] after DET). The number of children born per 1000 women was higher after DET (503) than after two cycles of SET (464), but DET resulted in significantly more multiple births (30.3% vs. 1.7%), fewer singleton births (26.8% vs. 37.4%), more premature births (46.5% vs. 18.1%), lower birth weight (2924.8 ± 756.8 g vs. 3264.4 ± 487.0), and significantly more very premature births. Two consecutive SETs lower the risks associated with DET with a comparable success rate in terms of the number of babies born.