ObjectiveTo systematically review the clinical effects of short-term and conventional fertilization for vitro fertilization-embryo transfer (IVF-ET). MethodsRandomized controlled trials (RCTs) about the clinical effects of short-term fertilization versus conventional fertilization for IVF-ET were searched in PubMed, The Cochrane Library (Issue 8, 2014), CBM, CNKI, WanFang Data and VIP from inception to August 2014. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data, and assessed methodological quality of included studies. Then meta-analysis was performed using RevMan 5.2 software. ResultsA total of six RCTs involving 1 373 patients were finally included. The results of meta-analysis indicated that:short-term fertilization was superior to conventional fertilization in increasing high quality embryo rates (OR=1.42, 95%CI 1.18 to 1.70, P=0.000 2) as well as clinical pregnancy rates (OR=1.67, 95%CI 1.33 to 2.09, P < 0.000 01). However, the two groups were alike in fertilization rates, polyspermy rates, and miscarriage rates. ConclusionCurrent evidence indicates that short-term fertilization is superior to conventional fertilization in increasing high quality embryo rates as well as clinical pregnancy rates. Due to limited quality and quantity of the included studies, the above conclusion should be verified by conducting more large-scale, high quality RCTs with long-term follow-up.