Ovarian stimulation with low-dose pure follicle-stimulating hormone in polycystic ovarian syndrome anovulatory patients: effect of long-term pretreatment with gonadotrophin-releasing hormone analogue.

A randomised clinical trial was performed to evaluate the effect of a 3-month gonadotrophin-releasing-hormone analogue (GnRH-a) in one cycle of ovulation induction with low-dose pure follicle-stimulating hormone (pFSH) in patients with polycystic ovarian syndrome (PCOS) anovulation. Twenty patients with chronic anovulation due to PCOS were randomised to ovulation induction with pFSH administered in a low-dose schedule with (10 patients) and without (10 patients) a 3-month pretreatment with GnRH-a. Ultrasound scan only monitoring of follicular growth, evaluation of plasmatic oestradiol at the day of triggering of ovulation with human chorionic gonadotrophin 5,000 IU and evaluation of plasmatic progesterone 8 days after were the main outcome measures. Ovulation occurred in 9 patients treated with pFSH and in 2 patients treated with GnRH-a plus pFSH. Five pregnancies in the pFSH group and no pregnancy in the GnRH-a group were obtained. Five cycles were stopped due to multifollicular growth in the GnRH-a group and 1 in the pFSH group. Pretreatment with a 3-month administration of a GnRH-a did not improve the ovulation rate and pregnancy rate in PCOS patient ovulation induction with low-dose pFSH.