Minimal Stimulation Using Letrozole in Poor Responders

Abstract

Background: Poor responders refer to women who undergo ovarian stimulation with suboptimal response and an optimal treatment for them has yet to be proven. Minimal stimulation which uses lower doses of gonadotropins than standard long protocols had been shown to yield fewer but higher quality embryos. Minimal stimulation had thus been proposed as an option for poor responders who do not benefit from longer and higher cost regimens. The aim of this retrospective study was to evaluate outcomes of poor responders who underwent minimal stimulation using letrozole and whether they are comparable to outcomes of conventional in vitro fertilization (IVF) in a tertiary center in Singapore.

Methods: This was a retrospective study of 43 poor responders who underwent minimal stimulation protocol in KK WomenWomens and ChildrenWomens Hospital IVF center between March 2011 and March 2014. The protocol involved sequential administration of letrozole followed by low-dose gonadotropins and a gonadotropin-releasing hormone (GnRH) antagonist. Primary outcomes included clinical pregnancy rate and live birth rate per patient. A subgroup analysis was done for women undergoing minimal stimulation protocol and having failed conventional IVF protocol in which their outcomes were compared.

Results: The average age at time of stimulation was 38.6 years old. Clinical pregnancies were achieved in nine women (20.9%), out of which eight (18.6%) were live births. In the subgroup analysis, cleavage rate obtained in the minimal stimulation protocol was significantly higher at 61.3% compared to the cleavage rate obtained in the conventional IVF cycle at 28.7%. There were no significant differences in the pregnancy and live birth rates of the two cycles.

Conclusion: Minimal stimulation protocol using letrozole produces a reasonable live birth rate in poor responders and potentially higher quality oocytes than conventional IVF protocol.




J Clin Gynecol Obstet. 2019;8(3):77-80
doi: https://doi.org/10.14740/jcgo557