Neonatal predictors of cognitive ability in adults born very preterm: a prospective cohort study.

AIM

To identify neonatal predictors to allow a developmental prognosis of the cognitive abilities of survivors born very preterm/very low birthweight (VLBW) into adult life.

METHOD

The Bavarian Longitudinal Study is a prospective whole-population study that followed 260 infants born very preterm/VLBW from birth to adulthood. Regression analyses examined which neonatal factors predicted adult IQ.

RESULTS

Neonatal morbidity, neonatal treatment, and early social environment of infants born very preterm/VLBW explained 37.6% of the variance in adult IQ. Seven unique early-life predictors of lower adulthood IQ were found: respiratory distress syndrome, intraventricular haemorrhage, problems with mobility, mechanical ventilation, less parenteral nutrition, low/middle socioeconomic status, and poor early parent-infant relationships. Specifically, modifiable factors such as mechanical ventilation predicted a drop of 0.43 IQ points for each day of treatment, adjusted for initial respiratory problems. Good early parent-infant relationships predicted an approximately 5-point increase in adult IQ, adjusted for other significant predictors such as socioeconomic status.

INTERPRETATION

Mechanical ventilation, parenteral feeding, and early parenting were identified as significant modifiable factors that were strongly related to adult IQ. Mechanical ventilation policies have changed but there is scope for early interventions that focus on positive parenting, which may reduce the adverse effects of very preterm/VLBW birth on cognitive abilities.