Maternal obesity and development of the preterm newborn at 2 years

Aim To evaluate to what extent extremely preterm children (<28 weeks' gestational age) of overweight (BMI 25-29) or obese (BMI ≥30) women are at increased risk of adverse development at 2 years measured with the Bayley Scales of Infant Development II in a multicenter prospective cohort study. Methods Heights and prepregnancy weights of the mothers of 852 preterm born children were collected and included in multinomial logistic regression models. Results Compared to newborns born to mothers with normal BMIs, newborns of obese mothers, but not those of overweight mothers, were more likely to have Bayley Scales indices more than 3 standard deviations below the reference mean (mental: OR = 2.1; 95% CI: 1.3, 3.5) (motor: OR = 1.7; 95% CI: 1.1, 2.7). These associations were even more prominent in children who did not have the intermittent or sustained systemic inflammation profile previously shown to be associated with severely impaired development (mental: OR = 4.6; 95% CI: 1.6, 14) (motor: OR = 3.7; 95% CI: 1.5, 8.9). Conclusion Maternal obesity is associated with an increased risk of impaired offspring development. Some of this impaired development cannot be attributed to confounding due to immaturity, socio-economic correlates or neonatal systemic inflammation.