Children who are born after assisted reproduction (ART) have a slightly increased risk of being born preterm, of having low birthweight and a higher perinatal mortality than spontaneously conceived children. The higher rate of multiple births among women having had ART can to some extent explain this. However, adverse outcomes persist even in ART singletons. The characteristics of the infertile parents have negative effects on the outcome, but also the hormone stimulation and the in vitro techniques are thought to play a role. A milder hormone stimulation and elective single embryo transfer, which reduces the number of multiples after ART, have improved the overall health of children born as a result of ART.