Abstract. Polycystic ovary syndrome (PCOS) is associated with low-quality oocytes. The aim of the present study was to investigate the effects of metformin (MET), N-acetylcysteine (NAC) and their combination on follicular fluid parameters, oocytes and embryo quality in PCOS patients. A prospective randomised placebo-controlled pilot study on 60 Iranian women with PCOS (aged 25–35 years) undergoing intracytoplasmic sperm injection (ICSI) was designed. Women were divided into four groups (n¼15 in each): (1) an MET, administered 1500 mgday 1 MET; (2) anNACgroup, administered 1800 mg day 1 NAC; (3) an NACþMETgroup; and (4) a placebo group. Drugs were administered from the 3rd day of previous cycle until the day of oocyte aspiration (6 weeks treatment in total). Data were analysed by one-way ANOVA, with significance set at P,0.05. The number of immature and abnormal oocytes decreased significantly in the NACcompared with placebo group, with a concomitant increase in the number of good-quality embryos in theNACgroup (P,0.05). Malondialdehyde levels decreased significantly in the NAC and NAC þ MET groups compared with the placebo-treated group (P,0.02). In addition, there were significant decreases in leptin levels in the NAC, MET and NAC þ MET groups compared with the placebo group (P,0.001). Insulin and LH levels were significantly lower in the METandNACgroups compared with the placebo-treated group (P,0.02).Weconcluded thatNACimproves oocyte and embryo quality and could be administered as an alternative to MET.
