Efficacy and Safety of Vaginal Estradiol Hemihydrate as an Adjunct to Oral Estradiol Valerate in Hormone Replacement Therapy-Frozen Embryo Transfer (HRT-FET) Cycles: A Retrospective Study

TL;DR

This study shows that adding vaginal estradiol hemihydrate to oral estradiol valerate improves endometrial thickness and pregnancy chances in frozen embryo transfer cycles.

Contribution

The novel finding is the effectiveness of vaginal estradiol hemihydrate as an adjunct in HRT-FET cycles for thin endometrium.

Findings

Endometrial thickness increased significantly from 7.47 mm to 8.68 mm after vaginal supplementation.

A clinical pregnancy rate of 50% was achieved with no adverse events reported.

Abstract

Objective: To evaluate the efficacy and safety of vaginal estradiol hemihydrate as an adjunct to oral estradiol valerate in improving endometrial thickness and pregnancy outcomes in the hormone replacement therapy-frozen embryo transfer (HRT-FET) cycle.

Materials and methods: This retrospective observational study was conducted at Kamala Polyclinic and Nursing Home, Mumbai, India, and included women aged 25-42 years undergoing HRT-FET treatment cycles between May and July 2024. Only those patients were included in this study whose endometrial thickness was <8 mm after administering oral estradiol valerate 12 mg OD for 12 to 15 days and who achieved a clinically adequate endometrium after co-treatment with vaginal estradiol hemihydrate 2 mg twice daily for two to three days. The study endpoints were measured as an increase in endometrial thickness, clinical pregnancy rate, and safety.

Results: Mean (SD) endometrial thickness increased significantly from 7.47 (0.97) mm to 8.68 (1.34) mm after vaginal supplementation (p < 0.001). The clinical pregnancy rate was 50%. No adverse events were reported.

Conclusion: In this study, administration of estradiol hemihydrate by vaginal route as an adjuvant helped to increase the endometrial thickness and was associated with higher clinical pregnancy in women with a thin endometrium following orally administered estradiol valerate alone.