Brief Alerts

Are Children Born After Cryopreservation as Embryos Healthy?

Source: Wennerholm UB, et al. Postnatal growth and health in children born after cryopreservation as embryos. Lancet 1998;351:1085-1090.

There has been a tremendous growth of new and novel techniques to address fertility problems in humans. One to two percent of all births in Sweden are born after in vitro fertilization (IVF) and embryo transfer. In many IVFs, the "fresh" embryo is transferred directly to the mother's uterus, but cryopreservation of the embryo is also frequently used if there is a delay before transfer. Cryopreservation of embryos is a well established procedure in most IVF centers. Questions about the long-term outcome of infants who were cryopreserved as embryos led to a study by Wennerholm and associates from Goteborg, Sweden.

Two hundred fifty-five children (160 singleton pregnancies and 96 twins) who were a result of in vitro fertilization and embryonic cryopreservation, were matched with 255 children born after IVF with fresh embryos and 252 children resulting from spontaneous pregnancies. The three groups were matched for maternal age, parity, single or twin pregnancies, and date of delivery. Growth, development, and general health of the infants were assessed periodically for at least 18 months in all three groups.

Postnatal growth features were similar for both singletons and twins in all three groups. There were 6/255 (2.4%), 9/255 (3.5 %), and 8/252 (3.2%) major malformations in the cryopreserved, standard IVF, and spontaneous groups, respectively. The prevalence of chronic diseases did not differ between the three groups.

Increasingly, American families afflicted with sterility are participating in IVF procedures with successful outcomes and they may seek counsel from their pediatricians. This well controlled and large study from Sweden is reassuring that the outcomes of IVF pregnancy are comparable with the outcomes of the old-fashioned way. -rae