Background & objectives: Studies have shown that insulin resistance and hyperinsulinaemia play a major role in the pathogenesis of polycystic ovary syndrome (PCOS). Therefore, the use of insulin sensitizing drugs in the treatment of PCOS has attracted the attention of medicine and researchers. The aim of this study was to investigate the effects of sitaformin (sitagliptin/metformin) and metformin on the quality of oocyte and embryo in classic PCOS patients undergoing intracytoplasmic sperm injection (ICSI). Methods: Sixty patients of PCOS (25-35 yr) were randomly allocated into three groups (n=20, each group): a metformin-treated group (administered metformin 500 mg twice daily), a sitaformin-treated group (administered sitaformin 50/500 mg twice daily) and a placebo group. Participants in all the groups received the drug two months prior to the start of the ovulation cycle and treatment continued until the day of the oocyte aspiration. Results: Serum insulin and total testosterone levels decreaseed significantly after treatment in both the treatment groups as compared to the placebo (P<0.05). A significant decrease in the number of immature oocytes [MI + germinal vesicle (GV) stage] was observed in metformin and sitaformin groups as compared to the placebo. In addition, sitaformin group when compared to the metformin group showed a significant decrease in the number of immature oocytes (P<0.05). The number of mature and normal MII oocytes increased significantly in both the treatment groups compared to the placebo group (P<0.05). The number of mature and normal oocytes increased in sitaformin group in comparison to the metformin group, but the difference was not significant. There was a significant increase in the number of grade I embryos, fertilization and cleavage rates in the sitaformin group compared to the other groups (P<0.05). Interpretation & conclusions: This is the first study to compare the impact of sitaformin with metformin on oocyte and embryo quality in women with PCOS undergoing a gonadotropin-releasing hormone (GnRH) antagonist cycle. In conclusion, sitaformin can be more effective in decreasing immature oocytes and increasing the quality of embryos than the use of metformin.
