The researchers performed separate analyses for babies born after ART, including in vitro fertilization and gamete intrafallopian transfer, and those born following the use of other fertility-related services, including ovulation induction, fertility-enhancing drugs, artificial insemination, or intrauterine insemination.
In an analysis comparing 1,749 babies born after non-ART fertility-related services with 17,748 naturally conceived infants propensity matched on maternal age, parity, plurality, race, gender, and year of birth, there were no differences in rates of various major birth defects.
The analysis of the association between ART and birth defects included 4,795 babies born following ART and 46,025 matched controls. The overall rate of major congenital malformations was significantly higher in the ART group.
In an analysis that separated singletons and multiples, the likelihood of birth defects was higher following ART for multiples only.
Limitations on the number of embryos transferred should be considered, Kelley-Quon said.