Gestational weight gain and child cognitive development.

BACKGROUND: The Institute of Medicine (IOM) recently revised gestational weight gain (GWG) guidelines, yet little is known about the association between extremes of GWG and child cognition.
METHODS: The authors examined this association using U.S. Collaborative Perinatal Project data (1959-73). Women with a calculable GWG and term, singleton children were eligible for inclusion. Children (31 968 individuals, including 8704 siblings) were assessed at 4 (Stanford-Binet Intelligence Scale, Graham-Ernhart Block Sort Test) and 7 years of age [Wechsler Intelligence Scales for Children, Wide Range Achievement Test (WRAT)]. Multiple regression with restricted cubic splines and generalized estimating equations (GEEs) was used. Fixed-effects (FE) models were also applied to control for confounders shared within sibships.
RESULTS: GWG displayed non-linear inverted U-shaped associations with most outcomes when the data were analysed using GEE, suggesting a detrimental influence of low and high GWG on cognition. After controlling for familial factors (FE), all associations were null except for a positive linear association between GWG above the IOM-recommended ranges and WRAT spelling (β = 1.41, 95% confidence interval: 0.13, 2.70).
CONCLUSIONS: Familial factors are important confounders of the association between GWG and cognitive development at 4 and 7 years of age. After controlling for such factors, GWG was generally unassociated with child development.