Child academic achievement in association with pre-pregnancy obesity and gestational weight gain

Background: Recent data suggest that children of mothers who are obese before pregnancy, or who gain too much weight during pregnancy, may be at an increased risk of cognitive impairments.

Methods: Mother-infant dyads enrolled in a birth cohort study in Pittsburgh, Pennsylvania (1983-1986), were followed from early pregnancy to 14 years postpartum (n=574). Math, reading and spelling achievements were assessed at ages 6 and 10 years using the Wide Range Achievement Test-Revised, and at age 14 years using the Wechsler Individual Achievement Test Screener. Self-reported total GWG was converted to gestational age-standardised z-scores. Generalised estimating equations were used to estimate the effects of GWG and pre-pregnancy body mass index (BMI) on academic achievement at 6, 10 and 14 years, while adjusting for maternal race, child sex, parity, employment, family income, maternal intelligence, maternal depression, pre-pregnancy BMI (in GWG models only) and the home environment.

Results: The mean (SD) BMI was 23.4 (5.7) kg/m(2) and the mean (SD) GWG reported at delivery was 14.4 (5.9) kg. There was a significant non-linear association between pre-pregnancy BMI and an offspring's academic achievement. At 6, 10 and 14 years, an offspring's academic scores were inversely associated with pre-pregnancy BMI beyond 22 kg/m(2). High GWG (>1 SD) was associated with approximately 4-point lower reading (adjusted β (adjβ) -3.75, 95% CI -7.1 to -0.4) and spelling scores (adjβ -3.90, 95% CI -7.8 to -0.2), compared with GWG -1 to +1 SD.

Conclusions: Future studies in larger and socioeconomically diverse populations are needed to confirm maternal weight and weight gain as causal determinants of a child's academic skills, and whether this effect persists into adulthood.