Is preterm birth associated with cognitive deficits?

Children born at a gestational age (GA) of 22 to 27 weeks are at significant risk of cognitive impairment at age 6.5 years, as are a substantial proportion of children born at a GA of 28-31 weeks. However, whereas neonatal conditions affect the prevalence of cognitive impairment of the former group (extremely preterm), these associations are not as evident in those in the latter group (very pre-term), according to a recent study.

Swedish investigators divided pre- term infants into 2 groups—those born extremely preterm (EPT) and those born very preterm (VPT). They assessed both groups for neurodevelopment at age 2.5 years and for cognitive outcomes at 6.5 years. Both assessments revealed mild-to-severe neurodevelopmental impairment. At 6.5 years, 8 of 91 children tested were diagnosed with cerebral palsy (4 VPT and4EPT)and6(4VPTand2EPT) with autism. Three of these 14 children had both cerebral palsy and autism. Neonatal factors independently related to 6.5-year outcomes were GA, retinopathy of prematurity, and treated persistent ductus arteriosus. But cognitive test scores at 2.5 years explained only 44% of intelligence score variance at 6.5 years. Given these results, the authors recommend following up into school age all children born before 32 weeks’ GA.

Thoughts from Dr. Farber

The test results at 2.5 years were corrected for prematurity. Although correction may be valid for younger children, I have always been leery that it is misleading by 2.5 years, presenting an overly optimistic picture. Unless the cognitive development of an extremely preterm child is solidly normal at 2.5 years, he or she still needs to be monitored closely.

This article was originally published on Contemporary Pediatrics®.

Reference

1. Kaul YF, Naseh N, Brodd KS, Böhm B, Holmström G, Hellström-Westas L. Average 2.5-year neurodevelop- mental test results in children born very preterm did not rule out cognitive deficits at 6.5 years of age. Acta Paediatr. 2021;110(3):846-854. doi:10.1111/apa.15586