# Correlation Between Hormonal Modulation and Pregnancy Outcomes: The Impact of Estrogen Priming and Endometrial Receptivity in Intrauterine Insemination

## TL;DR

This study found that estrogen priming before intrauterine insemination improves endometrial thickness and pregnancy outcomes.

## Contribution

The study demonstrates that estrogen priming enhances endometrial receptivity and pregnancy success in IUI procedures.

## Key findings

- Estrogen-primed women had significantly greater endometrial thickness (9.5 mm vs. 7.6 mm, p < 0.001).
- Endometrial thickness correlated with improved pregnancy outcomes (r = 0.41, p = 0.005).

## Abstract

Background: Intrauterine insemination (IUI) is one of the most commonly used assisted reproductive techniques for couples experiencing fertility issues. This study examined the difference in pregnancy rates between women who received estrogen priming before the ovulation trigger and those who did not.

Methods: This observational study was conducted at a fertility clinic and involved 80 women who underwent IUI, aged 24-38 years. The study spanned 12 months. The participants were divided into two groups: those who would receive estrogen priming (n = 40) and those who served as non-primed controls (n = 40). The sample size was calculated using OpenEpi 3.0.0 (Dean AG, Sullivan KM, Soe MM. OpenEpi: Open Source Epidemiologic Statistics for Public Health, Version. www.OpenEpi.com, updated 2013/04/06). Patients in the primed group were administered estradiol valerate (2 mg/day) from days 3 to 10 of the menstrual cycle. Endometrial characteristics, including thickness and pattern, and serum hormone levels were evaluated prior to ovulation triggering. Clinical pregnancy was confirmed via ultrasound. Data were analyzed using IBM SPSS Statistics for Windows, Version 26.0 (Released 2018; IBM Corp., Armonk, NY, US), with t-tests and chi-square tests applied. A p-value of 0.05 was considered statistically significant.

Results: Estrogen priming significantly improved endometrial thickness, with the primed group demonstrating a greater mean thickness compared to the control group (9.5 ± 1.3 mm vs. 7.6 ± 1.1 mm, p < 0.001). A positive correlation was observed between endometrial thickness and pregnancy outcomes (r = 0.41, p = 0.005).

Conclusion: The use of estrogen significantly enhanced endometrial growth and was associated with improved pregnancy outcomes following IUI. Administering estradiol as part of hormonal support may optimize endometrial receptivity and improve the efficacy of clinical fertility procedures.