Longer duration of gestation in term singletons is associated with better infant neurodevelopment

Background: Longer gestation at term and post-term age is associated with increased perinatal mortality. Nonetheless, recent neuroimaging studies indicated that longer gestation is also associated with better functioning of the child's brain. Aims: to assess whether longer gestation in term and post-term (in short: term) singletons is associated with better infant neurodevelopment. Study design: cross-sectional observational study. Subjects: Participants were all singleton term infants (n = 1563) aged 2–18 months of the IMP-SINDA project that collected normative data for the Infant Motor Profile (IMP) and Standardized Infant NeuroDevelopmental Assessment (SINDA). The group was representative of the Dutch population. Outcome measures: Total IMP score was the primary outcome. Secondary outcomes were atypical total IMP scores (scores <15th percentile) and SINDA's neurological and developmental scores. Results: Duration of gestation had a quadratic relationship with IMP and SINDA developmental scores. IMP scores were lowest at a gestation of 38·5 weeks, SINDA developmental scores at 38·7 weeks. Next, both scores increased with increasing duration of gestation. Infants born at 41–42 weeks had significantly less often atypical IMP scores (adjusted OR [95 % CI]: 0·571 [0·341–0·957] and atypical SINDA developmental scores (adjusted OR: 0·366 [0·195–0·688]) than infants born at 39–40 weeks. Duration of gestation was not associated with SINDA's neurological score. Conclusions: In term singleton infants representative of the Dutch population longer gestation is associated with better infant neurodevelopment scores suggesting better neural network efficiency. Longer gestation in term infants is not associated with atypical neurological scores.