Huang S, et al. - Different ovulation induction protocols were examined for their effectiveness in infertile women with polycystic ovary syndrome (PCOS) undergoing intrauterine insemination (IUI). Clomiphene citrate (CC), letrozole, or gonadotropins was used for ovulation induction among these women. Outcomes suggest that CC, letrozole and gonadotropins were equally effective and safe. As multi-follicular growth increased the multiple pregnancy rates without increasing the overall live birth rate, ovulation induction would strictly aim for mono-follicular growth. Researchers recommend letrozole as the treatment of the first choice in infertile women undergoing ovulation induction and IUI as this drug showed the highest mono-follicular growth rate.