Publication:

Optimizing in vitro fertilization outcomes in non-receptive endometrium using combined histological dating and endometrial receptivity array: a retrospective study

Background Precise identification of the window of implantation (WOI) is crucial for optimizing embryo transfer and improving assisted reproductive technology (ART) outcomes. While the endometrial receptivity array (ERA) evaluates molecular receptivity, histological endometrial dating is a simpler, cost-effective alternative. However, comparative evidence is limited. This study assessed concordance between ERA and histological dating and evaluated whether their combined use improves outcomes in patients with non-receptive endometrium.

Methods This retrospective study included 886 women undergoing ART between January 2021 and December 2025. Patients were categorized as ERA-receptive (n=562) or ERA non-receptive (n=324). Among non-receptive patients, outcomes were compared between those who underwent histological endometrial biopsy (EB) and those who did not. Subgroup analysis was conducted based on histological phase (proliferative versus secretory). Primary outcomes included clinical pregnancy, implantation, live birth, miscarriage, and ongoing pregnancy rates.

Results ERA-receptive patients showed significantly higher clinical pregnancy and implantation rates compared to non-receptive patients. Within the non-receptive group, histological evaluation was associated with improved clinical pregnancy (38.38% versus 23.02%), implantation (17.99% versus 9.73%), and live birth rates (31.82% versus 15.08%). Secretory-phase endometrium demonstrated superior clinical pregnancy (44.53% versus 24.59%) and live birth rates (40.15% versus 13.11%) compared to proliferative phase.

Conclusions Both ERA and histological dating are associated with improved ART outcomes. Histological assessment provides complementary value in ERA non-receptive patients. An integrated molecular and histological approach may enhance embryo transfer timing and improve reproductive success.