Postnatal growth restriction and neurodevelopment at 5 years of age: a European extremely preterm birth cohort study.

Objective: To investigate whether extrauterine growth restriction (EUGR) during the neonatal hospitalisation by sex among extremely preterm (EPT) infants is associated with cerebral palsy (CP) and cognitive and motor abilities at 5 years of age.

Study Design: Population-based cohort of births <28 weeks of gestation with data from obstetric and neonatal records and parental questionnaires and clinical assessments at 5 years of age.

Setting: 11 European countries.

Patients: 957 EPT infants born in 2011-2012.

Main Outcomes: EUGR at discharge from the neonatal unit was defined as (1) the difference between Z-scores at birth and discharge with <-2 SD as severe, -2 to -1 SD as moderate using Fenton's growth charts (Fenton) and (2) average weight-gain velocity using Patel's formula in grams (g) per kilogram per day (Patel) with <11.2 g (first quartile) as severe, 11.2-12.5 g (median) as moderate. Five-year outcomes were: a CP diagnosis, intelligence quotient (IQ) using the Wechsler Preschool and Primary Scales of Intelligence tests and motor function using the Movement Assessment Battery for Children, second edition.

Results: 40.1% and 33.9% children were classified as having moderate and severe EUGR, respectively, by Fenton and 23.8% and 26.3% by Patel. Among children without CP, those with severe EUGR had lower IQ than children without EUGR (-3.9 points, 95% Confidence Interval (CI)=-7.2 to -0.6 for Fenton and -5.0 points, 95% CI=-8.2 to -1.8 for Patel), with no interaction by sex. No significant associations were observed between motor function and CP.

Conclusions: Severe EUGR among EPT infants was associated with decreased IQ at 5 years of age.