BackgroundCurrently, optimal method of ovarian stimulation (OS) to in-vitro fertilization (IVF) in the patients with polycystic ovarian syndrome (PCOS) is unknown. The present research aims to study the efficiency of minimal-OS method in treatment of infertile patients with PCOS and also the effect of gonadotropin type (recombinant FSH (r-FSH) vs. urinary Human menopausal gonadotropin (u-HMG)) on treatment cycles with GnRH-antagonist.MethodsIn this randomized controlled trial, a total of 120 eligible patients were randomly allocated into four groups of OS to IVF: minimal-OS with r-FSH, minimal-OS with u-HMG, mild-OS with r-FSH and mild-OS with u-HMG. IVF outcomes of groups were analyzed statically.ResultsThe statistical analysis showed that there were significant differences among groups regarding stimulation duration (p < 0.0001), number of retrieved oocytes (p < 0.0001), number of obtained embryos (p < 0.0001). There were no statistically significant differences in fertilization rate (p = 0.289) and implantation rate (p = 0.757) among our participants. There were also significant differences among these four groups in terms of clinical pregnancy rate (/ET and /cycles) (p < 0.0001, p = 0.021, respectively) and live birth rate/cycles (p < 0.0001). Also cases of freeze all embryos due to prevention of ovarian hyper stimulation syndrome (OHSS) (p = 0.004).ConclusionsOn the basis of present results the minimal-OS with u-HMG may be one of optimal methods of control OS in the patients with PCOS in respect to serum levels of estradiol on the day of triggering final oocyte maturation, total dose of prescribed gonadotropin, the optimal number of oocytes and embryos obtained, rate of clinical pregnancy and the incidence of OHSS risk.Trial registrationNCT, NCT03876145. Registered 15/03/2019. Retrospectively registered,http://www.clinicaltrial.gov/NCT03876145.