A Meta Analysis On Effects Of Various Doses Of Letrozole For Ovulation Induction

Objective1．Compare the effects of letrozole5.0mg with that of letrozole2.5mg forovulation induction．2．Compare the effects of letrozole5.0mg with that of letrozole7.5mg forovulation induction．MethodsWith system evaluation method, comprehensive searches both English andChinese database and manual searches have been published in English and Chineseinformation and conference papers were searched to Dec2012. Collection of allrelevant randomized controlled trials (RCTs), quality assessment using the Jadadscore standards, and extract data, use the Cochran system evaluation softwareRevMan5.0of the Meta-analysis of homogeneous studies．Results1021articles were found with the search strategy mentioned above．8articleswere included after screening one by one according to the inclusion and exclusioncriteria．Among the8included articles，all of them are RCT．The results of Meta analysis are below：1．Meta—analysis of the comparision of the effects of letrozole5.0mg withthat of letrozole2.5mg for ovulation induction．Clinical evidence of the letrozole5.0mg and letrozole2.5mg used in inductingovulation available so far indicates the indexes of effectiveness，for example，diameterof mature follicle、ovulation rate、pregnancy rate、miscarriage rate，are notstatistically significant.Endometrial thickness of letrozole5.0mg group is thinner thanthat of the letrozole2.5mg group。The follicular mature time in letrozole5.0mg groupwas statistically less than that of letrozole2.5mg group。The number of maturefollicles in letrozole5.0mg group were statistically more than that of letrozole2.5mggroup.2．Meta-analysis of the comparision the effects of letrozole5.0mg with that of letrozole7.5mg for ovulation induction．The indexes of effectiveness such as，endometrial thickness、the number ofmature follicles、ovulation rate、pregnancy rate、miscarriage rate are not statisticallysignificant.The follicular mature time in letrozole7.5mg group was statistically lessthan that of letrozole5.0mg group.CONCLUSIONSThe evidence of clinical research showed that letrozole at the dose of5.0mg perday needed less time to achieve follicular maturity，produced more maturefollicles，led to thinner endometrial thickness.The follicular mature time in letrozole7.5mg group was statistically less than that of letrozole5.0mg group.