Baseline ovarian cyst formation following gonadotropin-releasing hormone analogues: their prevalence and impact on in vitro fertilization outcome

Abstract

One known complication of gonadotropin-releasing hormone (GnRH) agonist treatment for in vitro fertilization (IVF) cycles is the formation of functional ovarian cysts. The effect of baseline ovarian cysts on the outcome of IVF treatment is controversial. No prior studies have compared the prevalence of cyst formation in GnRH agonist versus GnRH antagonist stimulation protocols. Our objective was to determine the prevalence and significance of baseline follicular cysts on the response to controlled ovarian hyperstimulation and the outcome of IVF in women treated with a GnRH agonist versus a GnRH antagonist. Retrospective case-controlled study. Three-hundred and eighteen consecutive IVF cycles performed between January 2010 and December 2014 were analyzed. The subjects were grouped according to stimulation protocol (GnRH agonist vs. GnRH antagonist) and by the presence or absence of baseline ovarian cysts. We compared baseline estradiol levels, total gonadotropin dose used, total number of days of ovulation induction, number of cycle cancellations, number of oocytes retrieved, and the clinical and live birth rates. There was no significant difference in the prevalence of baseline ovarian cysts using a GnRH agonist versus antagonist protocol (14% vs. 9.5%, p = 0.269). The average time delay to initiate an IVF cycle was 8.9 days for the agonist cycles and 10.2 days for the antagonist cycles (range 0-28 days). The number of oocytes retrieved was lower in the group of patients with a baseline cyst treated with the antagonist protocol (4.7 with a cyst vs. 10.2 without a cyst, p = 0.039) as well as a significantly higher cycle cancellation rate (36% vs. 8.4%, p = 0.028, OR 6.16, 95% CI 1.51-25.12). This effect was not seen with the GnRH agonist protocol. There was no difference in the number of ampules of gonadotropins used for stimulation or total days of stimulation for either protocol. Finally, there was no significant difference between the groups according to the clinical pregnancy rate or live birth rate. The presence of a baseline ovarian cyst delays the time to initiate an IVF cycle; however, there is no significant difference in the prevalence of cyst formation between GnRH agonist and GnRH antagonist protocols. Although presence of a baseline ovarian cyst was associated with a lower number of oocytes retrieved and higher cycle cancellation rate, there is no negative impact on pregnancy rates when compared to cycles without cyst formation. Larger prospective studies are needed to confirm these findings.