The impact of routine chronic endometritis screening on clinical pregnancy outcomes in patients first receiving in vitro fertilization or intracytoplasmic sperm injection: A retrospective cohort study.

Objective: To evaluate the impact of routine screening for chronic endometritis (CE) through endometrial biopsy and immunohistochemical staining among patients first receiving in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment.

Methods: A total of 2108 patients first receiving IVF/ICSI treatment from July 2021 to June 2022 were enrolled in the retrospective cohort study. Patients enrolled were assigned into two groups: the routine screening group (N = 882) and the non-routine screening group (N = 838). Every patient in the routine screening group underwent routine CE screening during hysteroscopy while patients in the non-routine screening group underwent CE screening when suspicious CE manifestations were observed under hysteroscopy. Clinical pregnancy rates and live birth rates were compared between groups. Pregnancy outcomes were also compared between CE (N = 630) and non-CE (N = 755).

Results: The routine screening group had 395 clinical pregnancies (44.8%) and 356 live births (40.4%), while the non-routine screening group had 375 clinical pregnancies (44.7%) and 325 live births (38.8%). Single-factor regression analysis showed no statistically significant differences in clinical pregnancy (0.99 [0.83-1.0], P = 0.988) and live birth (0.96 [0.78-1.17], P = 0.647) between the two groups. Multivariate regression analysis yielded similar results for clinical pregnancy (1.07 [0.88-1.30], P = 0.503) and live birth (0.97 [0.94-1.00], P = 0.228) between the groups.

Conclusion: It is recommended to conduct CE screening only when suspicious CE manifestations were observed under hysteroscopy in infertile patients first receiving IVF/ICSI treatment and to administer standardized antibiotic treatment when pathological immunohistochemical staining indicates a positive result.