Study on the Optimal Definition of Extrauterine Growth Restriction in Preterm Infants Based on Neurodevelopmental Outcomes at Multiple Time Points

Heterogeneity in extrauterine growth restriction (EUGR) diagnostic criteria impedes clinical decision-making due to variable incidence reporting. This study established the optimal EUGR definition using neurodevelopmental outcomes at multiple time points. We evaluated 936 preterm infants, testing twelve EUGR definitions (3 curves × 4 dimensions) against abnormal developmental screening test (DST) results at corrected ages 3–6mo (T1), 9–12mo (T2), and 18–24mo (T3). Adjusted relative risks (aRR) were calculated with gestational age (GA) and small-for-gestational-age (SGA) subgroup analyses.EUGR incidence and DST abnormalities inversely correlated with GA (T3 abnormality: 62.5% in GA<32w). All definitions predicted T3 abnormalities (P<0.001), but efficacy varied substantially. Olsen cross-sectional performed best overall (aRR=4.13, 95%CI:3.07–5.57). Stratified analyses revealed:GA<34w: Fenton true longitudinal had highest validity (aRR=3.91); GA≥34w: INTERGROWTH-21st true cross-sectional was optimal (aRR=6.74); SGA subgroup: Olsen true cross-sectional predicted risk (aRR=2.90). Conclusion: EUGR definition selection requires GA and objective consideration. Olsen cross-sectional is recommended for universal screening; GA-stratified models enhance precision for high-risk interventions.