A cohort of 91 children from cryopreserved embryos and 83 control chil
dren who were conceived normally had their development assessed using
the Griffiths's scales of mental development. The controls (81 singlet
ons and two twins) of a similar age, sex, and social class were select
ed from siblings, cousins, and peers of the cryopreserved embryo group
(68 singleton, 20 twins, and three triplets). Children from cryoprese
rved embryos had a lower mean birth weight and mean gestational age an
d a higher proportion were born by caesarean section. One child from t
he cryopreserved embryo group had Down's syndrome, three had squints,
and four had conductive hearing loss while in the control children, si
x had squints, and nine had conductive hearing loss. In both groups, i
ncluding 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 10
5.69 (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 fi om cryopr
eserved embryos did not cause concern though formal testing had high-l
ighted small differences compared with other children conceived normal
ly and of a similar social class.