Received August 18, 2024
Accepted September 02, 2025

This systematic review and meta-analysis aimed to evaluate the benefit of GnRH agonist (GnRHa) in reproductive outcomes among women with adenomyosis undergoing IVF. The utility of GnRHa protocols for controlled ovarian stimulation (COS) and fresh embryo transfer, and the pretreatment with GnRHa before frozen-thawed embryo transfer were evaluated. The search spanned studies published in MEDLINE and Embase databases up to April 2024. Eight retrospective studies were included. The use of long GnRHa and antagonist protocol before COS exhibited significantly higher implantation rate compared to ultra-long GnRHa (OR 1.1, 95% CI 0.69-1.77 and OR 1.98, 95% CI 1.04-3.75, respectively), although no significant differences were observed in clinical and live birth rates. However, antagonist compared to long GnRHa protocol before COS improved live birth rate (OR 2.59, 95% CI 1.03-6.52). Pretreatment with GnRHa before FET among women with adenomyosis did not improve reproductive outcomes. In conclusion, there is no evidence regarding benefit of long or ultra-long GnRHa protocol before COS or before FET among women with adenomyosis undergoing IVF. In fact, the use of long GnRHa seem to worsen reproductive outcomes compared to antagonist protocols. Prospective trials are needed to assess the potential benefit of GnRHa among women with adenomyosis seeking fertility.