Fecundity disorders in older women: declines in follicular development and endometrial receptivity

Ectopic pregnancy is associated with increased risk of displaced implantation window: a retrospective study

BACKGROUND

To evaluate the risk factors associated with WOI (window of implantation) displacement based on ERT (endometrial receptivity test), and to confirm the association of ectopic pregnancy with WOI displacement.

METHODS

This is a retrospective study at the Reproductive Medicine Center of Xiangya Hospital from January 2020 to April 2024, consisting of 934 patients who performed ERT. The patients underwent 3771 assisted reproductive technology (ART) cycles and 2629 embryo transfer (ET) cycles, with each patient experiencing at least one implantation failure. The study utilized generalized estimation equation (GEE) models to examine factors associated with WOI displacement, adjusting for confounding factors like age, body mass index (BMI), and infertility type. Non-linear relationships between age or BMI with WOI displacement were explored using generalized additive models (GAM) with thresholds detected by segmented regression.

RESULTS

Among the patients, 60.17% were in the receptive phase, 39.40% in the pre-receptive phase, and 0.43% in the post-receptive phase. Ectopic pregnancy history increased the risk of WOI displacement by 62% (aOR 1.62, 95%CI 1.03-2.53, P = 0.035), patients over 35 years old had a 50% higher risk of WOI displacement compared to patients under 34 (aOR 1.50, 95% CI 1.12-2.00, P = 0.007). Secondary infertility showed a 26% lower risk of WOI displacement than primary infertility without statistical significance (aOR 0.74 95% CI 0.54-1.02, P = 0.062). BMI ≥ 22 kg/m2 was associated with a 25% increased risk of WOI displacement without statistical significance (aOR 1.25, 95% CI 0.94-1.67, P = 0.12).

CONCLUSION

Ectopic pregnancy and advanced age (≥ 35) are significantly associated with increased risk of WOI displacement. Primary infertility and higher BMI (≥ 22 kg/m2) tend to increase the risk of WOI displacement though without statistical significance.

CLINICAL TRIAL NUMBER

Not applicable.

Follicular development and endometrial receptivity of different androgen phenotypes in women with polycystic ovary syndrome

Objective

Polycystic ovary syndrome (PCOS) is an important factor contributing to infertility in reproductive-aged women. Hyperandrogenism (HA) plays an important role in the pathogenesis of PCOS. This study was conducted to explore the follicular development and endometrial receptivity of different androgen phenotypes in reproductive-aged patients with PCOS.

Methods

A total of 268 PCOS patients with infertility were recruited and divided into two groups according to the different androgen phenotypes in this study: abnormal menstruation and hyperandrogenism (AM-HA group, n = 127) and abnormal menstruation and polycystic ovarian morphology (AM-PCOM group, n = 141). The follicular development, endometrial receptivity, pregnancy rate, and live birth rate during the natural menstrual cycle were compared between the two groups.

Results

The number of dominant follicles, number of ovulations, and normal ovulation rate in the AM-HA group were significantly lower compared with those in the AM-PCOM group (p < 0.05). The endometrial thickness (ET), endometrial volume (EV), vascularization index (VI), flow index (FI), and vascularization flow index (VFI) on days 14 to 24 of the menstrual cycle before ovulation were significantly lower in the AM-HA group than in the AM-PCOM group (p < 0.05). The endometrial VI, FI, and VFI, the integrin αvβ3, and VEGF concentrations in the uterine fluid during the implantation window were significantly lower in the AM-HA group compared with the AM-PCOM group (p < 0.05). However, no statistically significant differences were observed in the uterine artery blood flow parameters, ET and EV, between the two groups (p > 0.05). The biochemical pregnancy rate, clinical pregnancy rate, ongoing pregnancy rate, and live birth rate in the AM-HA group were significantly lower compared with those in the AM-PCOM group (p < 0.05).

Conclusion

PCOS patients with the AM-HA phenotype were vulnerable to ovulation disorders and impaired endometrial receptivity, which resulted in reduced pregnancy rate. Treatment with HA is likely to become an effective approach for improving endometrial receptivity and fecundity disorders in patients with PCOS.

Age-related uterine changes and its association with poor reproductive outcomes: a systematic review and meta-analysis

BACKGROUND

The decline in women's fertility becomes clinically relevant between 35-40 years old, when there is insufficient ovarian activity, and it becomes more difficult to achieve pregnancy naturally and through artificial reproductive technologies. A competent endometrium is required for establishing and maintaining a pregnancy to term, however, experts in the field underestimate the contribution of endometrial age and its impact on reproductive outcomes remains unclear.

STUDY DESIGN

A systematic search of full-text articles available in PubMed was conducted to retrieve relevant studies published until March 2023. Search terms included: endometrium, uterus, age, aging, pregnancy, and oocyte donation. Terms related to reproductive pathologies were excluded. Eligibility criteria included original, rigorous, and accessible peer-reviewed work, published in English on the effect of age on the uterus and endometrium.

RESULTS

From 11,354 records identified, 142 studies were included for systematic review, and 59 were eligible for meta-analysis of endometrial thickness (n = 7), pregnancy rate (n = 22), implantation rate (n = 10), live birth rate (n = 10) and pregnancy loss rate (n = 11). Studies for the meta-analysis of reproductive outcomes only included transfers of embryos from ovum donation (ovum donors < 36 years old). Age shrinks the uterus; depletes endometrial blood supply through narrow uterine veins and a progressive loss of uterine spiral arteries; disrupts endometrial architecture and cellular composition; alters hormone production, shortening menstrual cycle length and impeding endometrial progression to the secretory stage; and dysregulates key endometrial functions such as adhesion, proliferation, apoptosis, and receptivity, among others. Women over 35-40 years old had significantly thinner endometrium (MD 0.52 mm). Advanced maternal age is associated with lower odds of achieving implantation (27%) and clinical pregnancy (20%), or higher odds of experiencing pregnancy loss (44%).

CONCLUSION

Due to the effect of age on endometrium reported in this review, managing patients with advanced maternal age may require considering the endometrial factor as a potential tissue to treat with anti-aging strategies. This review provides researchers and clinicians with an updated and in-depth summary of this topic, encouraging the development of new tailored anti-aging and preventive strategies for precision medicine in endometrial factor in infertility.

TRIAL REGISTRATION

PROSPERO 2023 (CRD42023416947).

GDF9His209GlnfsTer6/S428T and GDF9Q321X/S428T bi-allelic variants caused female subfertility with defective follicle enlargement

BACKGROUND

Antral follicles consist of an oocyte cumulus complex surrounding by somatic cells, including mural granulosa cells as the inner layer and theca cells as the outsider layer. The communications between oocytes and granulosa cells have been extensively explored in in vitro studies, however, the role of oocyte-derived factor GDF9 on in vivo antral follicle development remains elusive due to lack of an appropriate animal model. Clinically, the phenotype of GDF9 variants needs to be determined.

METHODS

Whole-exome sequencing (WES) was performed on two unrelated infertile women characterized by an early rise of estradiol level and defect in follicle enlargement. Besides, WES data on 1,039 women undergoing ART treatment were collected. A Gdf9Q308X/S415T mouse model was generated based on the variant found in one of the patients.

RESULTS

Two probands with bi-allelic GDF9 variants (GDF9His209GlnfsTer6/S428T, GDF9Q321X/S428T) and eight GDF9S428T heterozygotes with normal ovarian response were identified. In vitro experiments confirmed that these variants caused reduction of GDF9 secretion, and/or alleviation in BMP15 binding. Gdf9Q308X/S415T mouse model was constructed, which recapitulated the phenotypes in probands with abnormal estrogen secretion and defected follicle enlargement. Further experiments in mouse model showed an earlier expression of STAR in small antral follicles and decreased proliferative capacity in large antral follicles. In addition, RNA sequencing of granulosa cells revealed the transcriptomic profiles related to defective follicle enlargement in the Gdf9Q308X/S415T group. One of the downregulated genes, P4HA2 (a collagen related gene), was found to be stimulated by GDF9 protein, which partly explained the phenotype of defective follicle enlargement.

CONCLUSIONS

GDF9 bi-allelic variants contributed to the defect in antral follicle development. Oocyte itself participated in the regulation of follicle development through GDF9 paracrine effect, highlighting the essential role of oocyte-derived factors on ovarian response.

Analysis of clinical data of different endometrial pathological types in perimenopausal women with abnormal uterine bleeding

Objective

Early detection and diagnosis are important for improving the therapeutic effect and quality of life in patients with endometrial cancer (EC). This study aimed to analyze the clinical data of different endometrial pathological types in perimenopausal women with abnormal uterine bleeding (AUB) in order to provide evidence for the prevention and early diagnosis of EC.

Methods

A total of 462 perimenopausal women with AUB were enrolled in this prospective observational study. Endometrial biopsy was performed in patients with suspected endometrial lesions. According to the pathological examination results, the patients were divided into endometrial polyp group (EP) (n = 71), endometrial hyperplasia without atypia group (EH) (n = 59), atypical endometrial hyperplasia (AEH) (n = 36), and EC group (n = 27). The history risk factors and ultrasonic imaging characteristics of endometrium among the four groups were compared.

Results

Twenty-seven women were diagnosed with EC (5.84%). The prevalence rate of AEH and EC in the group of 51- to 55-year-old women was significantly higher than that in the groups of 40- to 45-year-old women and of 46- to 50-year-old women (P < 0.05). The age, body mass index, and history of diabetes gradually increased with the development of endometrial pathological types. In addition, the correlation index of endometrial blood flow increased gradually, and the proportion of uneven endometrial echo, unclear endometrial-myometrial junction (EMJ), and ovarian cyst also increased gradually. However, no statistically significant difference was found when comparing endometrial thickness (ET) and endometrial volume (EV) among endometrial pathological groups (P > 0.05). The ET, EV, endometrial vascularization index, endometrial flow index, and vascularization flow index in the ovarian cyst group were significantly higher (P < 0.05), and the proportion of uneven endometrium echo and unclear EMJ were significantly higher compared with that in the non-ovarian cyst group (P < 0.05).

Conclusions

The most common cause of perimenopausal women with AUB was benign endometrial lesions. However, women aged 51-55 years old with endometrial high risk factors and ovarian cyst should be alert to AEH and EC. Endometrial biopsy needs to be performed to determine endometrial malignancy in necessity.

Transcriptomic profiling of human granulosa cells between women with advanced maternal age with different ovarian reserve

BACKGROUND

Age-related diminished ovarian reserve (DOR) is not absolute. Some advanced maternal age (AMA) still have normal ovarian reserve (NOR) and often show better pregnancy outcomes. Exploring the transcriptomic profile of granulosa cells (GCs) in AMA could lead to new ideas for mitigating age-related diminished ovarian reserve.

AIM

This study aimed to analyze the transcriptomic profile of GCs in AMA with different ovarian reserve.

RESULTS

In total, 6273 statistically significant differential expression genes (DEGs) (|log2fc|> 1, q < 0.05) were screened from the two groups, among which 3436 genes were upregulated, and 2837 genes were downregulated in the DOR group. Through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, the potential functions of dysregulated genes in AMA with DOR or NOR were predicted. The GO enrichment analysis revealed that the DEGs were mainly enriched in obsolete oxidation-reduction process, mitochondrion, metal ion binding, ATP binding, etc. The KEGG pathway enrichment analysis revealed that the above-mentioned DEGs were mainly enriched in ferroptosis, regulation of actin cytoskeleton, oxidative phosphorylation, etc. Meanwhile, verification of the mRNA expression levels of DEGs revealed the possible involvement of "ferroptosis" in age-related diminished ovarian reserve.

CONCLUSIONS

From a new clinical perspective, we presented the first data showing the transcriptomic profile in GCs between AMA with different ovarian reserve. At the same time, we identified the role of ferroptosis in the GCs of AMA, providing a new biological basis for studying ovarian aging and improving pregnancy outcomes of AMA.

The impact of anti-Müllerian hormone on endometrial thickness in gonadotropin stimulation/intrauterine insemination cycles: is there an effect on pregnancy outcomes?

PURPOSE

To study the association, if any, between anti-Müllerian hormone (AMH) and pre-ovulatory endometrial thickness (ET) in gonadotropin/intrauterine insemination (IUI) cycles.

METHODS

This retrospective cohort study included a total of 964 patients undergoing 1926 gonadotropin/IUI cycles at an academic fertility center. Primary outcome measure was the association between serum AMH and measured ET on the day of and the day before human chorionic gonadotropin hormone (hCG) ovulation trigger. The effect of a model combining AMH and ET on early pregnancy outcomes was a secondary measure.

RESULTS

In 52.8% of cycles, ET was last assessed and recorded on the day of hCG administration, while in the remaining 47.2% on the day prior to trigger. In unadjusted regression models, AMH was weakly correlated with ET on hCG trigger day [bAMH (95%CI) = 0.032 (- 0.008, 0.070), p = 0.015]. When adjusting for potential confounders, the positive correlation became significant [0.051 (0.006, 0.102), p = 0.047]. Similar findings were observed when assessing the correlation between AMH and ET on the day prior to hCG trigger. ET was non-significantly associated with the odds of clinical pregnancy, when adjusting for potential confounders, except for when restricting the analysis to couples with idiopathic infertility [OR (95%CI), p-value: 0.787 (0.623, 0.993), 0.044].

CONCLUSION

Our findings support an effect of serum AMH on endometrial development in gonadotropin induced cycles, even when adjusting for the diagnosis of PCOS. ET was not associated with the odds of achieving a clinical pregnancy, except for couples with idiopathic infertility.

Transcutaneous electrical acupoint stimulation improves endometrial receptivity resulting in improved IVF-ET pregnancy outcomes in older women: a multicenter, randomized, controlled clinical trial

OBJECTIVE

To examine the effects and mechanisms of transcutaneous electrical acupoint stimulation (TEAS) on pregnancy outcomes in women undergoing in vitro fertilization (IVF)-embryo transfer (ET).

DESIGN, SETTING, AND PARTICIPANTS

This efficacy study was a multicenter, randomized, controlled clinical trial (RCT) in women receiving IVF-ET. The mechanistic study was a single-center RCT.

INTERVENTIONS

The participants received TEAS vs. no TEAS treatment.

MAIN OUTCOME MEASURES

In the efficacy study, the primary outcomes were the rates of clinical pregnancy, embryo implantation, and live birth. In the mechanistic study, sex hormones and endometrial protein expression were examined.

RESULTS

Ultimately, 739 participants were enrolled (367 and 372 in the TEAS and control groups, respectively). The clinical pregnancy rate was higher in the TEAS group than in the controls (55.1% vs. 46.7%, P = 0.03). There were no significant differences in embryo implantation, biochemical pregnancy, and live birth rates between the two groups (all P > 0.05) in the study population. In women > 35 years, the clinical pregnancy rates, embryo implantation rates and live birth rates in the TEAS and control groups were 48.9% vs. 23.7% (P = 0.004),30.8 vs. 13.9% (P = 0.001) and 34.0% vs. 19.7% (P = 0.06) respectively. In the mechanistic study with 120 participants, on the theoretical embryo implantation day, better developed endometrial pinopodes, elevated endometrial integrin α1β1/αVβ3, leukemia inhibitory factor, and elevated serum progesterone levels were found in the TEAS group compared with controls.

CONCLUSION

TEAS significantly improved the clinical pregnancy rate in women undergoing IVF-ET, especially in women of older age. It might be due to improved endometrial receptivity.

TRIAL REGISTRATION

ChiCTR-TRC-13003950.

Artificial Intelligence in the Assessment of Female Reproductive Function Using Ultrasound: A Review

The incidence of infertility is continuously increasing nearly all over the world in recent years, and novel methods for accurate assessment are of great need. Artificial Intelligence (AI) has gradually become an effective supplementary method for the assessment of female reproductive function. It has been used in clinical follicular monitoring, optimum timing for transplantation, and prediction of pregnancy outcome. Some literatures summarize the use of AI in this field, but few of them focus on the assessment of female reproductive function by AI-aided ultrasound. In this review, we mainly discussed the applicability, feasibility, and value of clinical application of AI in ultrasound to monitor follicles, assess endometrial receptivity, and predict the pregnancy outcome of in vitro fertilization and embryo transfer (IVF-ET). The limitations, challenges, and future trends of ultrasound combined with AI in providing efficient and individualized evaluation of female reproductive function had also been mentioned.

Clinical outcomes after elective double-embryo transfer in frozen cycles for women of advanced maternal age: A retrospective cohort study

We aimed to determine the clinical outcome of double cleavage-stage embryo transfers in frozen-thawed embryo transfer cycles for older women.This study analyzed a total of 8189 cleavage-stage frozen-thawed embryo transfer cycles between January 2013 and December 2017 at Sir Run Run Shaw Hospital. All cycles were sorted into 3 groups based on patient age: ≤35 years (Group A), 36 to 37 years (Group B), and ≥38 years (Group C). The clinical pregnancy rate (CPR), implantation rate (IR), live birth rate (LBR), miscarriage rate, multiple pregnancy rate (MPR), preterm birth rate, and low-birth-weight rate were compared between the 3 groups.Significant differences in CPR, IR, LBR, MPR, and premature birth rate were found among the 3 groups. The CPR, IR, LBR, and MPR in Group A were higher than those in Group C. Transfers of 2 high-quality embryos resulted in significant differences in CPR, IR, LBR, MPR, and neonatal weight among the 3 groups, but no differences in premature birth and abortion rates were observed. Transfers with 1 high-quality and 1 fair-quality embryo resulted in significant differences in CPR, IR, and LBR among the 3 groups. Comparison of transfers of 2 high-quality embryos with 1 high-quality and 1 fair-quality embryo showed that the CPR and LBR were significantly lower for the latter in Groups A and C, but Group B had no salient changes.Higher IR and LBR and lower MPR may be achieved by selection of optimal embryo types for patients of different ages. Two high-quality embryos need to be transferred in women older than 38 years. For women aged 36 to 37 years, 1 high-quality embryo or 1 high-quality plus 1 fair-quality embryo should be singled out for transfer. For women younger than 35 years, a single high-quality embryo should be selected for transfer.

Hormonal Replacement Treatment for Frozen-Thawed Embryo Transfer With or Without GnRH Agonist Pretreatment: A Retrospective Cohort Study Stratified by Times of Embryo Implantation Failures

OBJECTIVE

To evaluate the efficacy of the long-acting gonadotropin-releasing hormone agonist (GnRH-a) administration before hormone replacement treatment for frozen-thawed embryo transfer in women with different times of embryo implantation failures.

METHODS

A retrospective cohort study was performed between January 2015 and December 2019. A total of 9263 women who underwent frozen-thawed embryo transfer were included in the study. The study is divided into three parts based on the times of embryo implantation failures. The sample sizes were 4611 for no implantation failure, 3565 for one failure and 1087 for multiple failures. Two endometrium preparation protocols, HRT and HRT with GnRH-a pretreatment (G-HRT), were compared. Confounding factors were treated by propensity score matching and generalized estimation equation.

RESULTS

For women with no failure of embryo implantation, the live birth rate was not statistically different when they underwent HRT and G-HRT (HRT: 42.75% [498/1165], G-HRT: 45.24% [527/1165], P=0.2261). Similar outcome also appeared in women with one failure of embryo implantation (HRT: 47.22% [535/1133], G-HRT: 50.31% [570/1131], P=0.1413). For women with multiple failures of embryo implantation, the live birth rate was significantly difference (HRT: 38.74% [117/302], G-HRT: 45.48% [357/785], P=0.0449). When stratified by age, the live birth rate is similar for women older than 37 years. Generalized estimation equation showed that GnRH agonist pretreatment was independently associated with the live birth rate for women with multiple failures (adjust OR: 1.5, 95%CI: [1.12-2.00]).

CONCLUSION

For women with no/one failure of embryo implantation, the live birth rate is similar between HRT and G-HRT protocols. For women with multiple failure of embryo implantation, GnRH agonist pretreatment is beneficial to raise the live birth rate.

Thin endometrium is associated with the risk of hypertensive disorders of pregnancy in fresh IVF/ICSI embryo transfer cycles: a retrospective cohort study of 9,266 singleton births

BACKGROUND

Thin endometrial thickness (EMT) has been suggested to be associated with reduced incidence of pregnancy rate after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment, but the effect of thin endometrium on obstetric outcome is less investigated. This study aims to determine whether EMT affects the incidence of obstetric complications in fresh IVF/ICSI-embryo transfer (ET) cycles.

METHODS

We conducted a retrospective cohort study collecting a total of 9266 women who had singleton livebirths after fresh IVF/ICSI-ET treatment cycles at the Center for Reproductive Medicine Affiliated to Shandong University between January 2014 and December 2018. The women were divided into three groups according to the EMT: 544 women with an EMT ≤8 mm, 6234 with an EMT > 8-12 mm, and 2488 with an EMT > 12 mm. The primary outcomes were the incidence of obstetric complications including hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), placental abruption, placenta previa, postpartum hemorrhage (PPH) and cesarean section. Multivariable logistic regression analysis was performed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for associations between the EMT measured on the day of human chorionic gonadotropin (HCG) trigger and the risk of the outcomes of interest.

RESULTS

The HDP incidence rate of pregnant women was highest in EMT ≤ 8 mm group and significantly higher than those in EMT from > 8-12 mm and EMT > 12 mm group, respectively (6.8% versus 3.6 and 3.5%, respectively; P = 0.001). After adjustment for confounding variables by multivariate logistic regression analysis, a thin EMT was still statistically significant associated with an increased risk of HDP. Compared with women with an EMT > 8-12 mm, women with an EMT ≤8 mm had an increased risk of HDP (aOR = 1.853, 95% CI 1.281-2.679, P = 0.001).

CONCLUSION

A thin endometrium (≤8 mm) was found to be associated with an increased risk of HDP after adjustment for confounding variables, indicating that the thin endometrium itself is a risk factor for HDP. Obstetricians should remain aware of the possibility of HDP when women with a thin EMT achieve pregnancy through fresh IVF/ICSI-ET treatment cycles.