Extended Letrozole Treatment for Ovulation Induction and Clinical Pregnancy in Conventional Treatment-resistant Polycystic Ovary Syndrome Patients: A Prospective Parallel Randomized Clinical Trial.

Abstract

Background/purpose: Polycystic ovarian syndrome (PCOS) is the most frequent cause of anovulatory infertility. Due to the high rates of ovulation and pregnancies, Letrozole (LE) has recently been considered the first-line ovulation induction medication administered to PCOS patients. Nowadays, different clinical trials have examined various LE protocol methods to reach the best strategy for infertility therapy in PCOS patients.

Methods: This study was designed as a single-center, parallel randomized [1:1] clinical trial. It was registered on the World Health Organization trial registry of IRAN with registration number IRCT20110908007513N19. Eligible participants with PCOS resistant to conventional treatment were assigned to receive extended LE treatment for 7 days (group A) and 10 days (group B). Primary endpoints included ovulation rate and follicle measurements, while secondary endpoints assessed pregnancy rates and complications. A per-protocol analysis was considered.

Results: Among 55 participants, the mean age was 29.27, with a BMI of 25.51. In group A, 27/27 patients were ovulated, and lastly, 10 indicated clinical pregnancy. In group B, 27/28 patients were ovulated, and only 5 indicated clinical pregnancy. While the variation in clinical pregnancy rates between the groups in our study did not achieve statistical significance, the observed trend indicates a potentially significant clinical implication. Hormone profiles, follicle sizes, and endometrial thickness did not significantly differ between clinically pregnant and non-pregnant females in both groups. No complications were observed.

Conclusion: Although several conventional treatment-resistant females eventually became pregnant in a 7- or 10-day course of treatment, there are no notable differences between LE therapy in 7-day and 10-day groups. Further extensive studies are needed to validate the findings. Healthcare professionals should take this trend into account when assessing treatment alternatives, particularly within the framework of personalized patient care, as even slight enhancements in pregnancy rates can have significant effects.

World health organization trial registry of iran registration number: IRCT20110908007513N19.