The role of reproductive hormones in the associations of air pollution with oocyte-related outcomes remains unclear. In 6376 women undergoing assisted reproductive technology, we investigated the mediating role of reproductive hormones in the association between air pollutants during the 90 days pre-retrieval to gonadotropin start and oocyte-related outcomes. Results showed that nitrogen dioxide (NO2) was negatively associated with prolactin (PRL) (β [95% confidence interval (CI)] = -0.049 [-0.078, -0.020]), and ozone (O3) was negatively associated with luteinizing hormone (LH) (β [95% CI] = -0.064 [-0.093, -0.036]) and estradiol (E2) (β [95% CI] = -0.137 [-0.168, -0.106]). Furthermore, in the negative associations of air pollutant mixtures with hormones, O3 was consistently identified as the predominant risk contributor. Additionally, E2 was negatively associated with all oocyte-related outcomes [β ranges: -0.088 to -0.072; all false discovery rate P (P-FDR) < 0.01], whereas LH and PRL showed significant positive associations (β ranges = 0.028-0.419; all P-FDR < 0.01). Mediation analysis, which relies on statistical assumptions, suggested that PRL may partially explain the association between NO2 and total oocyte yield, and that LH and E2 may partially explain the association between O3 and total and mature oocyte yields. Network toxicology predicted that air pollutants may disrupt hormone-related pathways (such as estrogen signaling pathways) by regulating genes such as TP53, EGFR, and MAPK, compromising female fertility. In conclusion, our study provides novel epidemiological evidence and mechanistic clues to the adverse reproductive risk of air pollution in females.

BackgroundThe rising prevalence of infertility has substantially increased the demand for in vitro fertilization (IVF). While various controlled ovarian stimulation (COS) protocols exist, the gonadotropin-releasing hormone antagonist (GnRH-ant) protocol is valued for its efficacy in preventing premature luteinizing hormone (LH) surges. However, it involves high medication costs and requires frequent injections, which impose a significant burden on patients. Clomiphene citrate (CC), a classic oral ovulation induction agent, offers advantages such as low cost and convenient administration. With the widespread adoption of the “freeze-all” strategy, its potential adverse impact on the endometrium can be mitigated. Recent modifications to the CC protocol, combining it with adequate-dose gonadotropins, aim to balance efficacy and cost. However, well-designed studies directly comparing this modified CC protocol with the conventional GnRH-ant protocol in a general IVF population are lacking, particularly those incorporating comprehensive cost-effectiveness analyses.Methods3,157 patients undergoing IVF or intracytoplasmic sperm injection (ICSI) cycles using either the CC protocol or the GnRH-ant protocol were matched 1:1 using propensity score matching (PSM) based on female age, basal follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH), antral follicle count (AFC), body mass index (BMI), fertilization method, and sperm source. A total of 1,858 patients (929 per group) were included after matching. Embryological parameters and pregnancy outcomes were compared between the two groups, along with cost-effectiveness and sensitivity analyses.ResultsBaseline characteristics were well-balanced after PSM (with almost all standardized mean differences (SMD) < 0.1). The clinical pregnancy rate was comparable between the CC group and the GnRH-ant group (46.26% vs. 41.07%, P = 0.113), and the cumulative clinical pregnancy rate was also similar (51.60% vs. 51.79%, P = 1.000). The live birth rate (35.48% vs. 31.95%, P = 0.268) and cumulative live birth rate (35.48% vs. 38.29%, P = 0.398) were also comparable between the two groups. Compared to the GnRH-ant group, the CC group exhibited a higher Day 3 embryo formation rate (66.67% vs. 62.50%, P = 0.012), despite having lower numbers of follicles on the day of hCG trigger and retrieved oocytes (9.00 vs. 10.00 and 6.00 vs. 8.00, P < 0.0001). No significant differences were observed in the oocyte retrieval rate, oocyte maturation rate, fertilization rate, and blastulation rate between two groups. The cost of COS in the CC group was significantly lower than that in the GnRH-ant group (1,414.70 [741.50-2,915.50] CNY [~198 USD] vs. 7,266.24 [5,747.64-9,011.05] CNY [~1,017 USD], P < 0.0001), representing a saving of approximately 5,851.54 CNY (~819 USD; 80.53%). Cost-effectiveness analysis indicated that the CC protocol was superior across all outcome measures, including incremental cost-effectiveness ratios (ICERs) for oocyte, embryo, and clinical pregnancy. One-way sensitivity analysis (OWSA) indicated that the clinical pregnancy rate between the two groups was the most critical factor influencing the ICER for clinical pregnancy. Probabilistic sensitivity analysis (PSA) also suggested that in 98.50% of simulations, the CC protocol was more cost-saving.ConclusionsThe modified CC protocol was associated with ovarian stimulation effects and clinical outcomes comparable to those of the GnRH-ant protocol. Furthermore, it represented a more cost-effective ovarian stimulation strategy, significantly reducing treatment costs while maintaining a clinical pregnancy rate comparable to that of the GnRH-ant protocol.

Per- and polyfluoroalkyl substances (PFASs) may affect reproductive health, but their impact on male in vitro fertilization (IVF) outcomes remains unclear, and the underlying mechanisms are not yet elucidated. This cohort study included 132 men, aiming to evaluate the associations of PFAS exposure with IVF outcomes and explore potential biological mechanisms through lipid metabolomics. The results showed that perfluorooctanoic acid (PFOA) [(RR (95%CI): 0.875 (0.779, 0.983), P = 0.0246)], perfluoroundecanoic acid (PFUdA) [(RR (95%CI): 0.803 (0.690, 0.935), P = 0.0047)], perfluorododecanoic acid (PFDoA) [(RR (95%CI): 0.831 (0.713, 0.968), P = 0.0173)], perfluorotridecanoic acid (PFTrDA) [(RR (95%CI): 0.833 (0.719, 0.965), P = 0.0152)], and 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate (9Cl-PF3ONS) [(RR (95%CI): 0.925 (0.856, 1.000), P = 0.0497)] were inversely associated with the numbers of high-quality embryos. Increases in PFAS concentrations were associated with changes in specific lipid relative abundance, and specific lipid relative abundance was associated with IVF outcomes. In the group with poor IVF outcomes, the lipid pathways of phosphatidylcholine (PC) → diacylglycerol (DG) → PE → PS (Z-scores = -1.744 and -1.857, respectively) and triacylglycerol (TG) → DG → PE → PS (Z-scores = -1.985 and -2.080, respectively) were down-regulated, while the pathway of PS → PE → PC was up-regulated (Z-scores = 1.760 and 1.943, respectively). Network toxicology suggested that PFASs may be related to male infertility-associated lipid metabolism pathways through putative targets such as PTDSS and PEMT. This study provides epidemiological evidence that seminal PFAS exposure was associated with altered lipid metabolism and IVF outcomes. However, the associations were heterogeneous across lipid classes and IVF endpoints, suggesting that lipid metabolism may be involved in a complex biological response to PFAS exposure.

Multiple epidemiological studies across countries have linked exposure to endocrine-disrupting chemicals (EDCs) with adverse reproductive outcomes; however, the underlying mechanisms remain incompletely characterized. In this study, we profiled EDCs, lipids, and fatty acid metabolites in follicular fluid (FF) to elucidate metabolic pathways through which EDCs may affect reproductive outcomes. We further integrated network toxicology with an adverse outcome pathway (AOP) framework to delineate mechanistic routes by which EDCs may impair female reproductive health via metabolic disruption. We measured EDCs and metabolites in FF, and assessed assisted reproductive outcomes in 173 women from the SEARCH cohort. Overall, associations between EDCs and lipid or fatty acid profiles varied by chemical and class, consistent with previous studies. We further observed evidence of oocyte lipid metabolism dysregulation in relation to EDC exposure. Specifically, the diacylglyceride (DG) and phosphatidylethanolamine (PE) → phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) pathway was upregulated. Poorer oocyte developmental outcomes were characterized by significantly lower PE and LPE levels (log2FC: −0.30 and −0.07, respectively), and PE and LPE levels were associated with oocyte development (β: 0.141 and 0.090, respectively). Notably, phthalate exposure was associated with lower LPE (β [95% CI]: −0.001 [-0.002, 0.000]). Network and adverse outcome pathway (AOP) analysis identified mitochondrial dysfunction as a central mechanism mediating the association between EDC exposure and impaired fertility. In conclusion, these findings provide novel molecular insights into environmental determinants of female reproductive success.

Endocrine-disrupting chemicals (EDCs) exhibited the detriment in female reproductive health. Our objective was to investigate the individual and mixture effects of EDCs present in follicular fluid, the environment in which oocytes grow and develop, on early reproductive outcomes. We recruited 188 women seeking reproduction examination from the Study of Exposure and Reproductive Health (SEARCH) cohort between December 2020 and November 2021. We assessed the concentrations of 7 categories of 64 EDCs in follicular fluid, and measured early reproductive outcomes, including retrieved oocytes, mature oocytes, normal fertilized oocytes, and high-quality embryos. In this study Monomethyl phthalate (MMP) (2.17 ng/ml) were the compounds found in the highest median concentrations in follicular fluid. After adjusting for multiple testing, multivariate regression showed that multiple EDCs were significantly negatively associated with early assisted reproduction outcomes. For example, MMP showed a significant negative correlation with the number of high quality embryos (β: -0.1, 95 % CI: -0.15, -0.04). Specifically, eight types of EDCs were significantly negatively associated with four early assisted reproductive outcomes (β range: -0.2 ∼ -0.03). In the mixed exposure model, we found that mixtures of EDC were significantly negatively correlated with all four outcomes. In the quantile g-computation (QGCOMP) model, for each interquartile range increase in the concentration of EDC mixtures, the number of oocytes retrieved, mature oocytes, normally fertilized oocytes, and high-quality embryos decreased by 0.46, 0.52, 0.77, and 1.2, respectively. Moreover, we identified that phthalates (PAEs) predominantly contributed to the negative effects. Future research should validate our findings.

Air pollution is widely acknowledged as a significant risk factor for human health, especially reproductive health. Nevertheless, many studies have disregarded the potentially mixed effects of air pollutants on reproductive outcomes. We performed a retrospective cohort study involving 8048 women with 9445 cycles undergoing In Vitro Fertilization (IVF) and Intracytoplasmic Sperm Injection (ICSI) in China, from 2017 to 2021. A land -use random forest model was applied to estimate daily residential exposure to air pollutants, including sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), carbon monoxide (CO), ozone (O 3 ), and fine particulate matter (PM 2.5 ). Individual and joint associations between air pollutants and oocyte-related outcomes of ART were evaluated. In 90 days prior to oocyte pick-up to oocyte pick-up (period A), NO 2 , O 3 and CO was negatively associated with total oocyte yield. In the 90 days prior to oocyte pick-up to start of gonadotropin medication (Gn start, period B), there was a negative dose -dependent association of exposure to five air pollutants with total oocyte yield and mature oocyte yield. In Qgcomp analysis, increasing the multiple air pollutants mixtures by one quartile was related to reducing the number of oocyte pick-ups by -2.00 % (95 %CI: -2.78 %, -1.22 %) in period A, -2.62 % (95 %CI: -3.40 %, -1.84 %) in period B, and -0.98 % (95 %CI: -1.75 %, -0.21 %) in period C. During period B, a 1 -unit increase in the WQS index of multiple air pollutants exposure was associated with fewer number of total oocyte (-1.27 %, 95 %CI: -2.16 %, -0.36 %) and mature oocyte (-1.42 %, 95 %CI: -2.41 %, -0.43 %). O 3 and NO 2 were major contributors with adverse effects on the mixed associations. Additionally, period B appears to be the susceptible window. Our study implies that exposure to air pollution adversely affects oocyte-related outcomes, which raises concerns about the potential adverse impact of air pollution on women 's reproductive health.

Isolated effects of single endocrine-disrupting chemicals (EDCs) on male reproductive health have been studied extensively, but their mixture effect remains unelucidated. Previous research has suggested that consuming diet enriched in omega-3 polyunsaturated fatty acids (PUFA) might be beneficial for reproductive health, whether omega-3 PUFA could moderate the effect of EDCs mixture on semen quality remains to be explored. In this study of 155 male recruited from a reproductive health center in China, we used targeted-exposomics to simultaneously measure 55 EDCs in the urine for exposure burden. Regression analyses were restricted to highly detected EDCs (≥55%, n = 34), and those with consistently elevated risk were further screened and brought into mixture effect models (Bisphenol A, ethyl paraben, methyl paraben [MeP], benzophenone-1 [BP1], benzophenone-3, mono(3-carboxypropyl) phthalate [MCPP]). Bayesian Kernel Machine Regression (BKMR) and quantile-based g-computation (QGC) models demonstrated that co-exposure to top-ranked EDCs was related to reduced sperm total (β = −0.18, 95%CI: −0.29 – −0.07, P = 0.002) and progressive motility (β = −0.27, 95%CI: −0.43 – −0.10, P = 0.002), but not to lower semen volume. BP1, MeP and MCPP were identified as the main effect driver for deteriorated sperm motion parameters using mixture model analyses. Seminal plasma fatty acid profiling showed that high omega-3 PUFA status, notably elevated docosapentaenoic acid (DPA, C22:5n-3) status, moderated the association between MCPP and sperm motion parameters (total motility: β = 0.26, 95%CI: 0.01 – −0.51, Pinteraction = 0.047; progressive motility: β = 0.64, 95%CI: 0.23 – 1.05, Pinteraction = 0.003). Co-exposure to a range of EDCs is mainly associated with deteriorated sperm quality, but to a lesser extent on sperm quantity, high seminal plasma DPA status might be protective against the effect. Our work emphasizes the importance of exposomic approach to assess chemical exposures and highlighted a new possible intervention target for mitigating the potential adverse effect of EDCs on semen quality.

BACKGROUND:Humans are exposed to various chemicals, including organophosphate esters (OPEs), phthalates (PAEs), and phenols. The effects on early reproductive outcomes of in vitro fertilization (IVF) remain unclear. METHODS:We recruited 192 women and 157 men who underwent IVF treatment. A total of forty-nine urinary chemicals were detected, including six OPEs, fifteen PAEs, six parabens, two chlorophenols, nine bisphenols, five benzophenones, and six synthetic phenolic antioxidants. We examined the individual and joint effects of parental chemical exposure on early reproductive outcomes. RESULTS:We found that certain chemicals were associated with early reproductive outcomes in Poisson regression models. For example, urinary diphenyl phosphate was negatively associated with high-quality embryos in both female (β: -0.12, 95%CI: -0.17, -0.07) and male partners (β: -0.09, 95%CI: -0.15, -0.03). A negative association was found between mixed chemicals and high-quality embryos in Bayesian kernel machine regression, weighted quantile sum regression (β: -0.34, 95%CI: -0.60, -0.07), and quantile-based g-computation model (β: -0.69, 95%CI: -1.34, -0.05) among female partners. Paternal mixture exposure was not associated with early reproductive outcomes. CONCLUSIONS:Our results indicated that increased exposure to environmental chemicals was associated with adverse early reproductive outcomes of IVF, especially female partners.

Fertilization is a complex and highly regulated process that involves a series of molecular interactions between sperm and oocytes. However, the mechanisms of proteins involved in human fertilization, such as that of testis-specific SPACA4, remain poorly understood. Here we demonstrated that SPACA4 is a spermatogenic cell-specific protein. SPACA4 is expressed during spermatogenesis, upregulated in early-stage spermatids, and downregulated in elongating spermatids. SPACA4 is an intracellular protein that locates in the acrosome and is lost during the acrosome reaction. Incubation with antibodies against SPACA4 inhibited the binding of spermatozoa to zona pellucida. SPACA4 protein expression levels across different semen parameters were similar but varied significantly among patients. A prospective clinical study found no association between SPACA4 protein levels and fertilization or cleavage rates. Thus, the study suggests a novel function for SPACA4 in human fertilization in a non-dose-dependent manner. However, a larger clinical trial is required to evaluate the potential use of sperm SPACA4 protein levels to predict fertilization potential.

Objective To perform preimplantation genetic testing（PGT） for X-linked chronic granulomatosis using multiple displacement amplification（MDA） combined with haplotype analysis and pathogenic gene detection. Methods Sixteen short tandem repeat markers flanking both sides of CYBB gene were applied to construct haplotype analysis. Whole genome amplification was based on multiple displacement amplification and its product was further submitted to polymerase chain reaction and capillary electrophoresis to detect polymorphic STR sites and CYBB gene. The sex was diagnosed by the Amel locus. Results Two cycles of PGT were performed for a family. The pedigree analysis found seven polymorphic STR loci informative. A total of 16 embryos were diagnosed, of which 8 were genetically normal, 1 was carrier and 7 were abnormal. The diagnostic efficiency was 100%. The MDA success rate was 99.3%（143/144） and the allele drop-out rate was 14.0%（6/43）. A total of six transplantable blastocysts and three embryo transfer cycles were carried out for the patient, resulting in a single pregnancy and healthy baby boy at full term. Conclusion Multiple displacement amplification combined with specific amplification of pathogenic gene and haplotype analysis are effective and efficient in preimplantation genetic testing for X-linked chronic granulomatosis.

Preimplantation genetic testing (PGT) for monogenic disorders (PGT-M) for germline mosaicism was previously highly dependent on polymerase chain reaction (PCR)-based directed mutation detection combined with linkage analysis of short tandem repeats (STRs). However, the number of STRs is usually limited. In addition, designing suitable probes and optimizing the reaction conditions for multiplex PCR are time-consuming and laborious. Here, we evaluated the effectiveness of next generation sequencing (NGS)-based haplotype linkage analysis in PGT of germline mosaicism. PGT-M with NGS-based haplotype linkage analysis was performed for two families with maternal germline mosaicism for an X-linked Duchenne muscular dystrophy (DMD) mutation (del exon 45–50) or an autosomal TSC1 mutation (c.2074C > T). Trophectoderm biopsy and multiple displacement amplification (MDA) were performed for a total of nine blastocysts. NGS and Sanger sequencing were performed in genomic DNA of family members and embryonic MDA products to detect DMD deletion and TSC1 mutation, respectively. Single nucleotide polymorphism (SNP) sites closely linked to pathogenic mutations were detected with NGS and served in haplotype linkage analysis. NGS-based aneuploidy screening was performed for all embryos to reduce the risk of pregnancy loss. All nine blastocytes showed conclusive PGT results. Each family underwent one or two frozen-thawed embryo transfer cycles to obtain a clinical pregnancy, and the prenatal diagnosis showed that the fetus was genotypically normal and euploid for both families. NGS-SNP could effectively realize PGT for germline mosaicism. Compared with PCR-based methods, the NGS-SNP method with increased polymorphic informative markers can achieve a greater diagnostic accuracy. Further studies are warranted to verify the effectiveness of NGS-based PGT of germline mosaicism cases in the absence of surviving offsprings.

Aberrant DNA damage response (DDR) axis remains the major molecular mechanism for tumor radio-resistance. We recently characterized liquid-liquid phase separation (LLPS) as an essential mechanism of DDR, and identified several key DDR factors as potential LLPS proteins, including nucleolar protein NOP53. In this study, we found that NOP53 formed highly concentrated droplets in vivo and in vitro, which had liquid-like properties including the fusion of adjacent condensates, rapid fluorescence recovery after photobleaching and the sensitivity to 1,6-hexanediol. Moreover, the intrinsically disordered region 1 (IDR1) is required for NOP53 phase separation. In addition, multivalent-arginine-rich linear motifs (M-R motifs), which are enriched in NOP53, were essential for its nucleolar localization, but were dispensable for the LLPS of NOP53. Functionally, NOP53 silencing diminished tumor cell growth, and significantly sensitized colorectal cancer (CRC) cells to radiotherapy. Mechanically, NOP53 negatively regulated p53 pathway in CRC cells treated with or without radiation. Importantly, data from clinical samples confirmed a correlation between NOP53 expression and tumor radio-resistance. Together, these results indicate an important role of NOP53 in radio-resistance, and provide a potential target for tumor radio-sensitization.

BACKGROUND:Luteinizing hormone (LH) can stimulate mural granulosa cells to produce Amphiregulin (AREG), which can induce the resumption of meiosis in oocytes. Theca cells are present in the outer layer of follicles, providing communication with the pituitary axis through the established vascular system around the follicle. As LH target cells, it is unknown whether theca cells can produce AREG after LH stimulation.METHODS:Primary cultured human theca cells were treated with LH (with or without the inhibitor of PKA, H89), or agonists of adenylate cyclase (forskolin or db-cAMP). The mRNA and protein levels of AREG were evaluated by RT-qPCR, immunochemistry, immunofluorescence, western blotting, and ELISA.RESULTS:Immunohistochemistry of normal ovarian tissue obtained in the early-mid follicle phase showed that AREG expression was absent in both the theca layer and the granulosa cell layer of antral follicles. Double immunofluorescent staining revealed colocalization of AREG and CYP17A1 in human theca cells and colocalization of FSHR and AREG in human granulosa cells isolated from follicular fluid collected during IVF/ICSI after hCG trigger. LH significantly increased the mRNA and protein levels of AREG in human theca cells and the concentration of AREG in the culture medium. Forskolin and db-cAMP, activators of the cAMP/PKA signalling pathway, also significantly increased the mRNA and protein levels of AREG in human theca cells and the concentration of AREG in the culture medium. H89 antagonized the stimulating effect of LH on AREG expression in human theca cells. In addition, the concentration of AREG was lower in polycystic ovarian syndrome (PCOS) follicular fluid than in normal follicular fluid. The mRNA levels of AREG were significantly lower in PCOS granulosa cells and theca cells than in normal granulosa cells and theca cells.CONCLUSION:LH can stimulate the expression of AREG in human theca cells, and the adenylate cyclase/cAMP/PKA cascade may mediate this process. Expression of AREG is decreased in PCOS theca cells compared to normal theca cells, with or without LH stimulation.

To determine the application value of next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidies (PGT-A). We conducted a retrospective case–control study on a cohort of frozen-thawed embryo transfer (FET) cycles following preimplantation genetic testing for monogenic disorders (PGT-M) between 2014 and 2017. Cycles that produced live births or early miscarriages were divided into live birth group (n = 76) or miscarriage group (n = 19), respectively. The NGS-based aneuploidy screening was performed on the multiple displacement amplification (MDA) products of the embryonic trophectoderm biopsy samples that were cryopreserved following PGT-M. In the live birth group, 75% (57/76) embryos were euploid and 14.5% (11/76) were aneuploid. The remaining 10.5% (8/76) embryos were NGS-classified mosaic with the high- (≥ 50%) and low-level (< 50%) mosaicism rates at 7.9% (6/76) and 2.6% (2/76), respectively. In the miscarriage group, only 23.5% (4/17) embryos were aneuploid, while 58.8% (10/17) were euploid and 17.6% (3/17) were NGS-classified mosaic with the high- and low-level mosaicism rates at 11.8% (2/17) and 5.9% (1/17), respectively. For live birth and miscarriage groups, the transferable rate was 82.9% (63/76) and 70.6% (12/17), respectively, whereas the untransferable rate was 17.1% (13/76) and 29.4% (5/17), respectively. The application of NGS-based PGT-A remains questionable, as it may cause at least one in six embryos with reproductive potential to be discarded and prevent miscarriage in less than one in three embryos in single-gene disease carriers.

This study aimed to evaluate the value of long-read sequencing for preimplantation haplotype linkage analysis. The genetic material of the three β-thalassemia mutation carrier couples was sequenced using single-molecule real-time sequencing in the 7.7-kb region of the HBB gene and a 7.4-kb region that partially overlapped with it to detect the presence of 17 common HBB gene mutations in the Chinese population and the haplotypes formed by the continuous array of single-nucleotide polymorphisms linked to these mutations. By using the same method to analyze multiple displacement amplification products of embryos from three families and comparing the results with those of the parents, it could be revealed whether the embryos carry disease-causing mutations without the need for a proband. The HBB gene mutations of the three couples were accurately detected, and the haplotype linked to the pathogenic site was successfully obtained without the need for a proband. A total of 68.75% (22/32) of embryos from the three families successfully underwent haplotype linkage analysis, and the results were consistent with the results of NGS-based mutation site detection. This study supports long-read sequencing as a potential tool for preimplantation haplotype linkage analysis.

随着胚胎冷冻保存技术的发展以及冻融胚胎移植(FET)活产率的不断提高,FET在全球范围内的应用日益广泛.FET周期子宫内膜准备方案的理想选择是在获得最好妊娠率的同时拥有最安全的母胎结局.临床上FET最常用的两种子宫内膜准备方案是自然周期方案和激素替代周期方案.迄今为止,关于FET周期最佳的子宫内膜准备方案尚存在争议.本文主要针对这两种主流的子宫内膜准备方案的优缺点、有效性及安全性进行综述.

Our study established an effective next-generation sequencing (NGS) protocol for four-factor preimplantation genetic testing (PGT) using alpha- and beta-thalassemia, human leukocyte antigen (HLA) typing, and aneuploidy screening. Three couples, in whom both partners were alpha- and beta-double thalassemia carriers, underwent PGT between 2016 and 2018. These individuals sought an opportunity for hematopoietic stem cell transplantation to save their children from beta-thalassemia major. A total of 35 biopsied trophectoderm samples underwent multiple displacement amplification (MDA). PGT for alpha- and beta-thalassemia and HLA typing were performed on MDA products using NGS-based single-nucleotide polymorphism (SNP) haplotyping. Although two samples failed MDA, 94.3% (33/35) of samples were successfully amplified, achieving conclusive PGT results. Furthermore, 51.5% (17/33) of the embryos were diagnosed as unaffected non-carriers or carriers. Of the 17 unaffected embryos, nine (52.9%) were tested further and identified as euploid via NGS-based aneuploid screening, in which five had HLA types matching affected children. One family did not achieve any unaffected euploid embryos. The two other families transferred HLA-matched and unaffected euploid embryos, resulting in two healthy 'savior babies.' NGS-PGT results were confirmed in prenatal diagnosis. Therefore, NGS-SNP was effective in performing PGT for multipurpose detection within a single PGT cycle.

Previous observational studies have shown that exposure to ambient temperature and air pollution were associated with the incidence of gestational diabetes mellitus (GDM). However, the susceptible time window of non-optimal temperature on GDM is still unknown, and the interaction with air pollution has not been examined. We conducted a prospective cohort study in Guangzhou, China to investigate the windows of susceptibility of temperature extremes and variability on the risk of GDM and to explore any interaction effect with air pollution. Daily maximum (Tmax), minimum temperature (Tmin) and diurnal temperature range (DTR) were obtained from Guangdong Meteorological Service. Distributed lag non-linear models with a logistic regression were applied to assess the effect of temperature extremes and DTR in different weeks of gestation on GDM. To examine the interaction effect, relative excess risk due to interaction index, attributable proportion and synergy index were calculated. There were 5,165 pregnant women enrolled, of which 604 were diagnosed with GDM (11.7%). Compared with a reference temperature (50th percentile of Tmax), we found that extreme high temperature (99th percentile of Tmax) exposure during 21st and 22nd gestational weeks was associated with an increased risk of GDM. Extreme low temperature (1st percentile of Tmax) exposure during 14th to 17th weeks increased the risk of GDM. We observed that per 1 °C increment of DTR during 21st to 24th weeks was associated with an elevated GDM risk. No interaction effect of temperature extremes or variability with air pollution on GDM were observed. Our results suggested that non-optimal temperature is an independent risk factor of GDM. The time window of susceptibility for extreme temperatures and DTR exposure on the risk of GDM generally occurred in second trimester of pregnancy. In the context of climate change, our study has important implications for reproductive health and justifies more research in different climate zones.

Research question: Which of the two mainstream endometrial preparation regimens, assisted natural cycle (NC) or hormone replacement treatment cycle (HRT), help frozen-thawed embryo transfer (FET) cycles after preimplantation genetic testing (PGT) achieve better clinical outcomes? Design: This retrospective analysis included 3400 vitrified-warmed single blastocyst transfer cycles after PGT from January 2011 to November 2020, and involved 2332 patients with regular menstrual cycles. The decision to proceed with an assisted NC (n = 827) or HRT (n = 2573) before FET was reached based on a combination of patient preference and physician guidance. Clinical pregnancy rate, live birth rate, early miscarriage rate and obstetric outcomes were compared. Results: No significant difference was observed between the assisted NC and HRT groups in terms of clinical pregnancy rate (51.6% versus 50.7%, P = 0.634), live birth rate (44.0% versus 43.4%, P = 0.746) or early miscarriage rate (12.6% versus 12.0%, P = 0.707). Multivariate analysis indicated that the endometrial preparation protocol was not an independent factor for a clinical pregnancy or live birth. In the HRT group, the Caesarean section rate (64.7% versus 51.9%, P < 0.001) and pregnancy complication rate (20.2% versus 13.8%, P = 0.003) were significantly higher. The two groups were not statistically different with respect to gestational age, early preterm birth rate, fetal weight or fetal birth defect rate. Conclusions: For patients undergoing a PGT-FET cycle involving a single blastocyst transfer, using assisted NC and HRT for the endometrial preparation could lead to comparable rates of clinical pregnancy and live birth. Additionally, NC is safer than HRT in terms of avoiding pregnancy complications and adverse obstetric outcomes.

While widely used for ovulation induction in assisted reproductive technology, the clinical efficacy of letrozole for endometrial preparation prior to frozen-thawed embryo transfer (FET) cycles remains yet to be elucidated. We performed a meta-analysis to compare pregnancy outcomes after letrozole use with those of other endometrial preparation protocols in patients undergoing FET. PubMed, Scopus, Embase and the Cochrane Library were searched for eligible studies. Clinical pregnancy rate (CPR), live birth rate (LBR) and birth defect rate (BDR) were analysed using odds ratio (OR) and 95% confidence interval (CI). A total of 10 studies representing 75 968 FET cycles were included. Comparable CPR and LBR were observed when comparing letrozole administration with natural cycle (OR 1.24, 95% CI: 0.69 – 2.24; OR 1.18, 95% CI: 0.60 – 2.32), artificial cycle (OR 1.46, 95% CI: 0.87 – 2.44; OR 1.39, 95% CI: 0.77 – 2.52), and artificial cycle with gonadotropin-releasing hormone agonist suppression (OR 1.11, 95% CI: 0.78 – 1.59; OR 1.18, 95% CI: 0.82 – 1.68). Pooled results of the limited studies comparing letrozole with human menopausal gonadotropin demonstrated a similar CPR between groups (OR 1.46, 95% CI: 0.29 – 7.21, two studies), but the letrozole group had a statistically lower LBR (OR 0.67, 95% CI: 0.52 – 0.86, one study). No increased BDR was observed in the letrozole group compared to natural cycles or artificial cycles (OR 0.98, 95% CI: 0.60 – 1.61; OR 1.39, 95% CI; 0.84 – 2.28). This pooled analysis supports the use of letrozole as an efficacious and safe alternative to mainstream regimens for endometrial preparation in FET cycles.