Postnatal health and welfare of offspring conceived in vitro: A case for epidemiological studies

In vitro fertilization (IVF) has established itself as an important techniq ue in human assisted reproduction and in livestock improvement. In both hum ans and livestock the possible long-term effects on health and welfare of o ffspring born after IVF and in vitro culture to the blastocyst stage are st ill largely unknown. Epidemiological studies in humans, using data collecte d for individuals born after normal (i.e. non-assisted) pregnancies, have p rovided evidence for associations between prenatal life events and adult-li fe disease. Due to the relatively short time that elapsed since the first I VF baby was born, comparable studies for IVF offspring are not yet possible . However, animal experiments and epidemiological studies with the availabl e data from the livestock industry (mainly dairy cattle) may contribute to a better understanding of the risks involved. (C) 1999 by Elsevier Science Inc.