Respiratory distress syndrome in moderately late and late preterm infants and risk of cerebral palsy: a population-based cohort study

OBJECTIVES Infant respiratory distress syndrome (IRDS) is a known risk factor for intracerebral haemorrhage/intraventricular haemorrhage (ICH/IVH) and periventricular leucomalacia. These lesions are known to increase the risk of cerebral palsy (CP). Thus, we wanted to examine the long-term risk of CP following IRDS in moderately late and late preterm infants. DESIGN Population-based cohort study. SETTING All hospitals in Denmark. PARTICIPANTS We used nationwide medical registries to identify a cohort of all moderately and late preterm infants (defined as birth during 32-36 full gestational weeks) born in Denmark in 1997-2007 with and without hospital diagnosed IRDS. MAIN OUTCOMES MEASURES We followed study participants from birth until first diagnosis of CP, emigration, death or end of follow-up in 2014. We computed the cumulative incidence of CP before age 8 years and used Cox's regression analysis to compute HRs of IRDS, comparing children with IRDS to those without IRDS. HRs were adjusted for multiple covariates. RESULTS We identified 39 420 moderately late and late preterm infants, of whom 2255 (5.7%) had IRDS. The cumulative incidence of CP was 1.9% in infants with IRDS and 0.5% in the comparison cohort. The adjusted HR of CP was 2.0 (95% CI 1.4 to 2.9). The adjusted HR of CP was 12 (95% CI 4.5 to 34) in children with IRDS accompanied by a diagnosis of ICH/IVH. After restriction to children without diagnoses of perinatal breathing disorders other than IRDS, congenital heart disease and viral or bacterial infections occurring within 4 days of birth, the overall adjusted HR was 2.1 (95% CI 1.4 to 3.1). CONCLUSIONS The risk of CP was increased in moderately late and late preterm infants with IRDS compared with infants without IRDS born during the same gestational weeks.