Background: To explore the incidence of chronic endometritis (CE) in patients with infertility and different forms of adenomyosis and analyze potential high-risk factors for infection. Methods: This retrospective cohort study included 154 patients with infertility in the Liuzhou Maternity and Child Healthcare Hospital. Among them, 77 patients with adenomyosis were divided into four subgroups based on magnetic resonance imaging (MRI): internal, exterior, intramural, and full-thickness. Meanwhile, 77 patients did not have adenomyosis. Hysteroscopy and endometrial biopsy were performed in the proliferative phase. The main outcome measures were the morphology of the endometrium, syndecan-1 (CD138) immunohistochemical staining, clinical characteristics, and prevalence of CE in the adenomyosis subgroups. Results: In comparison to the non-adenomyosis group, the adenomyosis group had significantly higher body mass index (BMI) and CA125 levels. The menstrual cycle in the adenomyosis group was significantly shorter, and menarche was significantly earlier. In comparison to the non-adenomyosis group, the adenomyosis group had a significantly higher diagnostic rate of CE (75.3% vs. 46.8% according to hysteroscopy and 74.0% vs. 33.8% according to histopathology, both with p < .050). The incidence of CE was significantly lower in patients with internal adenomyosis when compared with the other three subgroups. Increased BMI contributed to a higher risk of CE. Conclusions: The prevalence of CE was significantly higher in patients with adenomyosis and infertility. The differences in the incidence of CE are closely associated with the classification of adenomyosis. When patients with infertility are diagnosed with adenomyosis, it is recommended to identify the subtype and screen for endometritis.

Background: Endometrial thickness (EMT) is a crucial indicator of endometrial receptivity in assisted reproductive technology (ART). However, its relationship with pregnancy outcomes remains unclear, especially across different cycle types such as fresh in vitro fertilization-embryo transfer (IVF-ET), frozen-thawed embryo transfer (FET), and preimplantation genetic testing for aneuploidy embryo transfer (PGT-ET). The clinical significance of EMT and its optimal range for improving ART outcomes remain subjects of debate.Methods: This retrospective cohort study analyzed data from 80,585 ART cycles conducted between July 2008 and December 2022 at a private reproductive center, including 25,683 fresh IVF-ET, 33,112 FET, and 1,071 PGT-ET cycles. EMT was measured via ultrasound on the day of HCG administration and grouped into ranges for comparison. Primary outcomes included live birth rates (LBR) and clinical pregnancy rates (CPR) across EMT ranges. Statistical analyses, including chi-square tests, receiver operating characteristic (ROC) analysis, and adjusted risk ratio (aRR) calculations, were performed to evaluate the association between EMT and pregnancy outcomes.Results: The relationship between EMT and LBR was non-linear, with no single cutoff value. LBR varied significantly across EMT ranges, peaking at approximately 12 mm in fresh IVF-ET cycles and around 10 mm in FET and PGT-ET cycles. Higher EMT was generally associated with improved LBR and CPR, but predictive power was limited (AUC: 0.56–0.60). Compared to an EMT of 10–11.9 mm, fresh IVF-ET cycles with EMT <10 mm had significantly lower LBR (aRR: 0.60–0.86), while those with EMT ≥12 mm had higher LBR (aRR: 1.12–1.17). Similar trends were observed in FET and PGT-ET cycles, although sensitivity to EMT variations was lower, particularly in PGT-ET cycles. Miscarriage rates (MR) showed no significant differences across EMT groups.Conclusion: This study demonstrates that EMT has a non-linear association with LBR and CPR across fresh IVF-ET, FET, and PGT-ET cycles, with no single cutoff value. While higher EMT generally correlates with improved outcomes, its overall predictive value for LBR is limited. The findings underscore the need for individualized evaluation of EMT based on cycle type to optimize reproductive outcomes in ART.

This study aimed to evaluate the predictive value of relative change in E2 levels during controlled ovarian stimulation (COS) on embryo development and pregnancy outcomes in assisted reproductive technology (ART). We retrospectively analyzed 9,376 patients who underwent their first fresh ART cycle from January 1, 2020, to December 31, 2022. Patients were classified into four groups based on relative change in E2 levels: low response group, moderate response group, moderate-high response group, and high response group. The primary outcomes were blastocyst formation rate, clinical pregnancy rate, and live birth rate, while secondary outcomes included miscarriage rate and ectopic pregnancy rate. Most cycles (96.5%) demonstrated an increase in E2 levels during COS. The blastocyst formation rate significantly increased across the groups (low response group: 0.13, moderate response group: 0.21, moderate-high response group: 0.28, high response group: 0.34; P < 0.001). Multivariable logistic regression showed significantly higher blastocyst formation rates in the moderate response group (adjusted OR = 2.012, 95% CI: 1.687–2.399), moderate-high response group (adjusted OR = 4.613, 95% CI: 3.853–5.523), and high response group (adjusted OR = 11.295, 95% CI: 9.192–13.880) compared to the low response group. Both clinical pregnancy rate and live birth rate were significantly higher in the moderate-high response group and high response group compared to the low response group (clinical pregnancy rate: 54.5% and 61.5% vs. 35.5%, adjusted RR = 1.21 [95% CI: 1.03–1.42] and 1.27 [95% CI: 1.08–1.51]; live birth rate: 44.9% and 52.0% vs. 25.7%, adjusted RR = 1.27 [95% CI: 1.06–1.52] and 1.35 [95% CI: 1.11–1.64]). However, no significant differences were observed in either clinical pregnancy rate or live birth rate between the moderate response group and low response group (clinical pregnancy rate: adjusted RR = 1.07 [95% CI: 0.91–1.25]; live birth rate: adjusted RR = 1.11 [95% CI: 0.92–1.33]). No significant differences in miscarriage rate or ectopic pregnancy rate were observed across the groups. Higher E2 responses were associated with improved embryo development and better pregnancy outcomes.

Background: Chronic endometritis (CE), characterized by CD138 ⁺ plasma cell infiltration, has been proposed to impair reproductive outcomes in assisted reproductive technology (ART). However, current evidence remains inconsistent, and diagnostic criteria vary widely. This study aimed to evaluate whether CE diagnosis and antibiotic treatment influence clinical pregnancy, live birth, and miscarriage outcomes following in vitro fertilization with fresh embryo transfer (IVF-ET) and frozen embryo transfer (FET). Methods: We retrospectively analyzed 3,041 embryo transfer cycles (1,507 IVF-ET; 1,534 FET) from 1,401 infertile women treated at the Reproductive Medicine Center of Liuzhou Hospital, Guangzhou Women and Children’s Medical Center (2008–2023). Chronic endometritis (CE) was primarily defined as the presence of ≥1 CD138 ⁺ plasma cell per 10 high-power fields (HPFs, ×400). Standard therapy was doxycycline 100 mg twice daily for 14 days. Outcomes were analyzed per transfer cycle using Poisson regression with robust standard errors and propensity score weighting. Results: Untreated CE patients had comparable live birth and clinical pregnancy rates to non-CE patients in both IVF-ET (live birth 37.7% vs. 36.7%) and FET (39.0% vs. 37.9%), and were also associated with a lower observed miscarriage risk after IVF-ET (adjusted RR 0.67, 95% CI 0.46–0.97). Among CE patients, antibiotic treatment did not improve outcomes compared with no treatment (IVF-ET live birth 36.8% vs. 37.7%; FET 41.5% vs. 38.7%; all p > 0.05). Similarly, post-treatment “cured” and “persistent” CE groups showed no significant differences in live birth or miscarriage rates in either transfer type. Exploratory analyses revealed context-dependent trends, but most interactions were nonsignificant. Conclusion: In this large single-center cohort, CE defined by CD138 ⁺ plasma cell infiltration was not associated with reduced clinical pregnancy or live birth rates, and no statistically significant benefit of antibiotic treatment was observed. The observed reduction in miscarriage risk among CE patients suggests complex immunological dynamics. Routine CE screening in all ART candidates may be unnecessary, and targeted evaluation for high-risk subgroups warrants further investigation.

Insulin resistance (IR) is a key metabolic disturbance that adversely affects assisted reproductive technology (ART) outcomes. In women with polycystic ova