Objective: To estimate the association between pre-existing maternal and pregnancy-related factors and developmental delay in early childhood in moderately preterm-born children.
Methods: We measured development with the Ages and Stages Questionnaire at age 43-49 months in 834 moderately preterm-born (between 32 0/7 and 35 6/7 weeks of gestation) children born in 2002-2003. We obtained data on preexisting maternal, maternal pregnancy-related, fetal, and delivery-related factors. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) and attributable risks for developmental delay adjusted for sociodemographic and lifestyle variables.
Results: Attributable risk for developmental delay for small-for-gestational-age (SGA, as a proxy for intrauterine growth restriction [IUGR]) was 14.2% (SGA 21.9%, no SGA 7.7%, P<.05, adjusted OR 2.75, CI 1.25-6.08), for preexisting maternal obesity 10.5% (obesity 18.0%, no obesity 7.5%, P<.01, adjusted OR 2.73, CI 1.35-5.52), for multiple pregnancy 4.2% (multiple 12.0%, singleton 7.8%, P<.05, adjusted OR 1.86, CI 1.02-3.42), and for male sex 9.3% (male 13.0%, female 3.8%, P<.001, adjusted OR 4.20, CI 2.09-8.46). No other preexisting or pregnancy-related maternal factors or any delivery-related factors were associated with increased risk of developmental delay.
Conclusions: Of all preexisting maternal and pregnancy-related factors studied, SGA, maternal prepregnancy obesity, being one of a multiple, and male sex were associated with the risk of developmental delay in early childhood after moderately preterm birth. Reinforced focus on prevention of IUGR, preconception lifestyle interventions aiming at weight reduction in fertile women, and reinforced efforts to reduce rates of multiple pregnancies in assisted reproduction may all contribute toward more favorable developmental outcomes in moderately preterm-born children.
Level of evidence: II.