Objective: To estimate the congenital malformations in in vitro fertilization-embryo transfer and naturally conceived children by means of meta-analysis, so as to provide the evidence for improving reproductive technology research.
Methods: We searched databases ( ISI Web of Knowledge, Medline, CNKI from 1999 to 2007 using "in vitro fertilization" or "in vitro fertilization and embryo transfer", in combination with "congenital malformations", also performed a manual search of citations from relevant original studies. Then all the studies applied a meta-analysing with software of Stata 10.
Results: Eight publications were identified and found no heterogeneity (Q = 3.7, P = 0.3) The total rate of malformations was higher in in vitro fertilization-embryo transfer infants than the naturally conceived. The pooled RR for the study was 1.3 (95% CI: 1.26 - 1.43, Z = 8.67, P = 0.00). The cumulative summary effects showed that the larger the sample size, the more accurate the estimation. Publication bias were not found in the study, by using Egger's test method (P = 0.2). In dividing the type of the newborn malformations, the rate of cardiovascular defects in in-vitro fertilization-embryo transfer infants was higher than in the naturally conceived. The summy RR for the study was 1.48 (95% CI: 1.2 -1.7, Z = 4.5, P = 0. 0).
Conclusions: The total rate of malformations and the cardiovascular defects in in-vitro fertilization-embryo transfer infants was higher than in the naturally conceived.