The Effectiveness Of Letrozole And Clomiphene Citrate For Induction Ovulation In Women With Polycystic Ovary Syndrome: A Meta Analysis

Objective: To assess the effectiveness of letrozole and clomiphene citrate(CC)for induction ovulation in women with polycystic ovary syndrome.Methods: Studies were searched through PUBMED, EMBASE and the Cochrane Central Register of Controlled Trials in order to identify randomized controlled trails (RCTs) comparing letrozole with clomiphene citrate in ovulation induction treatment. The quality of the included studies was critically appraised. STATA ?9.2 software was used for meta-analysisResults: Six studies were included in the meta-analysis. 1096 patients were involved, 1775 cycles of the ovulation induction treatment were included, and 883 cycles were used letrozole, 892 cycles were used clomiphene citrate. There was statistically significant difference in the less of the numbers of dominant follicle[SMD=-1.064,95%CI(-1.175~-0.953),p=0.000]in the letrozole group comparing to clomiphene citrate group. There was no statistically significant difference in the endometrial thickness at the time of HCG administration [SMD=1.268,95%CI(0.730~ 1.807),p= 0.638], ovulatory rate[RR=1.002,95%CI(0.834~1.204),p=0.983], pregnancy rate [RR=0.991,95%C(I0.793~1.238),p=0.935]between the letrozole group and the clomiphene citrate group.Conclusions: The numbers of dominant follicle was less when used the letrozole for induction ovulation in women with polycystic ovary syndrome, to reduce multiple pregnancy rate and ovarian hyperstimulation syndrome. But in the endometrial thickness, ovulatory rate and pregnancy rate, letrozole is as effective as clomiphene citrate for induction ovulation in patients with polycystic ovary syndrome. There is no evidence to show any advantage to the use of letrozole over clomiphene citrate.It needs to be further confirmed through more well-designed, multi-centered, large-sample randomized controlled trials.