Effectiveness Of Letrozole Versus Clomiphene Citrate In Intrauterine Insemination Cycles:a Systematic Review And Meta-analysis

Objective To evaluate the effectiveness of letrozole versus clomiphene citrate inintrauterine insemination cycles.Methods We searched Cochrane Central Register of Controlled Trials(CENTRAL)(Issue3of12, March2013)﹑Pubmed(2001-2013.3)﹑Embase(2001-2013.3)、Web ofScience(2001-2013.3)﹑CBM （2001-2013.3）﹑CNKI （2001-2013.3）﹑WanFang（2001-2013.3）﹑VIP(2001-2013.3),and tried to collect literature of other sources forrelevant randomized controlled trials(RCTs) comparing letrozole and clomiphene citratein intrauterine insemination cycles. Two investigators independently screened the literarureand collected dada, we also appraised the quality of all the included trials according to theCochrane Review’s Handbook version5.1.0.We used Revman5.2for Meta-analyses.Results Twelve RCTs involving2962patients were included, and all of the studies are ofunclear risk of bias. The results of the Meta-analyses showed that when using letrozole andclomiphene citrate alone or combining with gonadotropin at the same time,the clinicalpregnancy rate (including pregnancy rate per person and pregnancy rate per cycle)、miscarriage rate、multiple pregnancy rate and the rate of OHSS between the two groupswere all of no significant difference. the descriptive analysis of one study showed that theclinical pregnancy rate and miscarriage rate in clomiphene citrate-resistant polycystic ovarysyndrome(PCOS)patients were of no signifinant difference when using letrozole and clomiphene citrate alone or combining with metformin(MET) in intrauterine inseminationcycles. A sensitivity analysis showed that clinical pregnancy rate was significant higherthan clomiphene citrate alone in intrauterine insemination cycles when using letrozolealone;and the descriptive analyses of two RCTs also showed that the clinical pregnancy rateof using letrozole was significant higher than using clomiphene citrate combinedgonatropin;but the miscarriage rate between the two groups were of no signifinantdifference.Conclusions Comparing to clomiphene citrate,the usage of letrozole in intrauterineinsemination cycles is an effective approach,but there is no definite evidence demonstratingthat lerozole in intrauterine inseminantion cycles is more effective than clomiphene citrate,and there should be more well-designed RCTs in large sample and multicenter designaccording to different patients of various causes resulting to infertility or different protocolsof medicine to confirm whether letrozole is more effective than clomiphene citrate inintrauterine insemination cycles,and the conclusion of this systematic review and Metaanalysis will also be constantly updated.