Abstract

A cohort of 91 children from cryopreserved embryos and 83 control children who were conceived normally had their development assessed using the Griffiths's scales of mental development. The controls (81 singletons and two twins) of a similar age, sex, and social class were selected from siblings, cousins, and peers of the cryopreserved embryo group (68 singleton, 20 twins, and three triplets). Children from cryopreserved embryos had a lower mean birth weight and mean gestational age and a higher proportion were born by caesarean section. One child from the cryopreserved embryo group had Down's syndrome, three had squints, and four had conductive hearing loss while in the control children, six had squints, and nine had conductive hearing loss. In both groups, including the child with Down's syndrome, the mean Griffiths's quotient was greater than the standard 100. In the children from cryopreserved embryos, the singleton and multiple birth subgroups had statistically similar assessment results. The mean (SD) Griffiths's quotient was 105.69 (13.55) in children from cryopreserved embryos and 108.18 (9.80) in controls at a chronological age of 25.08 (12.86) and 29.19 (14.65) months respectively. Overall, the development in children from cryopreserved embryos did not cause concern though formal testing had highlighted small differences compared with other children conceived normally and of a similar social class.