Comparison of effects of letrozole or clomiphene citrate combined with HMG for ovulation induction in women with polycystic ovary syndrome

Objective:To evaluate the effectiveness of letrozole(LE)or clomiphene citrate(CC)combined with HMG for ovulation induction in women with polycystic ovary syndrome(PCOS).Methods:The data of 211 infertile women with PCOS undergone ovulation induction treatment were collected for the retrospective study.The patients were divided into three groups according to the treatments:LE+HMG,CC+HMG,and HMG-only.The ovulation and pregnancy rate,the rate of mono follicular development,HMG dose used per cycle and the mean duration of treatment were compared among the three groups.Results:The ovulation rate in LE+ HMG group(91.5%)and CC+ HMG group(86.8%)was significantly higher than that in HMG-only group(71.7%)(P 0.01).The rate of mono follicular development in LE+HMG group was significantly higher than in HMG-only group(85.3% vs.60.5%,P0.01),but not significantly higher than in CC+HMG group.No significant differences were found in pregnancy rates among three groups(25.3% vs.22.7% vs.26.3%,P0.05).The mean duration of treatment in LE+HMG group[(15.07±2.41)days]and in CC+HMG group [(15.27±2.47)days]wassignificantly shorter than that in HMG-only group [(16.91±2.66)days](P0.01).HMG dose used in LE+HMG group[(482.3±168.2)U]and CC+HMG group [(486±169.0)U]was significantly lower than that in HMG-only group[(595.5±196.6)U](P0.01).Conclusions:LE or CC combined with HMG not only reduces the duration of stimulation and total HMG dose used for ovulation induction,but also achieves higher ovulation rate.Moreover,administration of letrozole combined with HMG is helpful to obtain mono follicular development.