When comparing individuals who were all born late-preterm, those who grow faster as infants report better grades in school and do better in tests of cognitive ability as adults, as shown recently by Sara Sammallahti and colleagues in a study published in Pediatric Research.
Late preterm birth occurs close to the lower limit of full-term pregnancy, between 34 weeks and 0 days and 36 weeks and 6 days of gestation, and accounts for the majority of preterm births. Although late preterm infants suffer from fewer complications and receive less intensive monitoring and treatment than more immature babies, they are at an increased risk of early health problems, poorer neurocognitive functioning and problems in school, compared with term-born peers.
In this study of 108 late preterm adults who participated in the Arvo Ylppö Longitudinal Study, we found that those participants who gained more weight and grew more rapidly in head circumference as infants had higher IQ at 25 years of age and higher grades in comprehensive school, and they were less likely to have received special education, compared with slower-growing late preterm peers. In contrast, we did not find differences in mental health outcomes at 25 years of age. The associations were not explained by gestational age, parental education, prenatal growth patterns, manifest developmental disability or congenital malformations, or common pregnancy or neonatal disorders.
To alter the trajectory of neurodevelopment, early intervention is important. Our study suggests that environmental factors such as care and nutrition during the neonatal period may affect both early growth and long-term neurodevelopment, and early growth problems could help identify those at risk. The study also encourages further research into how interventions in infancy could compensate for the long-lasting risks associated with late preterm birth.
/ Sara Sammallahti, M.Psych., MD+PhD student
University of Helsinki
sara.sammallahti at helsinki.fi