Objective To analyze published literature about the clinical studies on elective single versus double embryo transfer using meta-analysis, so as to provide more convincing evidence for the clinical application of elective single embryo transfer.
Methods We electronically searched foreign and domestic biomedical databases including PubMed, Ovid, EMbase, MEDLINE and CENTRAL, to collect randomized controlled trials (RCTs) on elective single versus double embryo transfer. According to Cochrane systematic review method, two reviewers independently screened studies according to inclusion and exclusion criteria, extracted data, and assessed methodological quality of the included studies. Then, meta-analysis was performed using RevMan 5.1 software.
Results A total of 9 RCTs involving 2 784 cases were included, of which, 1 452 were in the trial group while the other 1 332 were in the control group. The results of meta-analysis indicated that, compared with elective double embryo transfer, during each transfer period elective single embryo transfer reduced the live birth rate (RR=0.66, 95%CI 0.59 to 0.73, P lt;0.000 01), multiple pregnancy rate (RR=0.05 95%CI 0.02 to 0.11, P lt;0.000 01), preterm birth rate (RR=0.39, 95%CI 0.26 to 0.60, P lt;0.000 1), and low birth weight rate (RR=0.25, 95%CI 0.15 to 0.44, P lt;0.000 01). However, it had no effect on the ectopic pregnancy rate (RR=0.55, 95%CI 0.11 to 2.77, P=0.47), miscarriage rate (RR=1.33, 95%CI 0.92 to 1.91, P=0.13), and neonatal mortality rate (RR=0.31, 95%CI 0.03 to 2.76, P=0.29).
Conclusion Compared with elective double embryo transfer, during each transfer period elective single embryo transfer reduces the live birth rate, multiple pregnancy rate, preterm birth rate, and low birth weight rate. No significant difference was found between the two groups in the other indicators.
Citation: WANG Zhihui,LA Xiaolin,ZHAO Jing,GONG Xiaoyun,HU Bo,WANG Peng. Feasibility of Elective Single Cleavage-Stage Embryo Transfer: A Meta-Analysis. Chinese Journal of Evidence-Based Medicine, 2013, 13(10): 1251-1257. doi: 10.7507/1672-2531.20130214 Copy