Postnatal growth and health in children born after cryopreservation as embryos

Background There is uncertainty about the health of children born from in-vitro fertilisation (IVF) with cryopreserved embryos. We investigated the postnatal growth and health (up to 18 months) of these children compared with those born after standard IVF with fresh embryos and those from spontaneous pregnancies. Methods 255 children from cryopreserved embryos were matched by maternal age, parity, single or twin pregnancy, and date of delivery with 255 children born after IVF with fresh embryos, and 252 children from spontaneous pregnancies. The main endpoint was growth; secondary endpoints were the prevalence of chronic illness, major malformations, cumulative incidence of common diseases, and development during the first 18 months. Growth was assessed by comparison with standard Swedish growth charts and by standard deviation scores. Findings Growth features were similar for both singletons and twins in the three groups. There were 6 (2-4%) of 255, 9 (3-5%) of 255, and 8 (3-2%) of 252 major malformations in the cryopreserved group, standard IVF, and spontaneous groups, respectively (p=0-6 between the cryopreserved and standard IVF group). The prevalence of chronic diseases did not differ between the three groups, with 18-0%, 15-3%, and 16-7% of children with a chronic illness in the cryopreserved group, standard IVF, and spontaneous groups, respectively. Interpretation The cryopreservation process does not adversely affect the growth and health of children during infancy and early childhood. Minor handicaps, behavioural disturbances, learning difficulties, and dysfunction of attention and perception cannot be ruled out at this age.