Predictive ability of the Hammersmith Neonatal Neurological Examination for identifying severe neurodevelopmental impairment in infants born very preterm

AIM: To evaluate the predictive ability of the Hammersmith Neonatal Neurological Examination (HNNE) at term-corrected age (TCA) for severe neurodevelopmental impairments at 2 years corrected age in infants born very preterm. METHOD: This retrospective study evaluated 88 infants, born at less than 29 weeks' gestation or weighing less than 1250 g using the HNNE at TCA (37 + 0 to 41 + 6 weeks). Neurodevelopmental outcomes at 2 years corrected age were determined using the Bayley Scales of Infant and Toddler Development. The diagnostic accuracy of the HNNE was assessed according to its ability to predict severe motor (< 74.5), cognitive, and language (< 71.2) impairments. RESULTS: The HNNE demonstrated moderate diagnostic performance for severe motor impairment (sensitivity = 75.0%, specificity = 64.5%, area under the curve [AUC] = 0.80), with lower scores associated with poorer outcomes (median = 20.3; p = 0.04). Performance was weaker for cognitive (sensitivity = 66.7%, specificity = 61.9%, AUC = 0.73) and language (sensitivity = 44.4%, specificity = 63.0%, AUC = 0.62) outcomes. High negative predictive values (NPV) across all domains (NPV = 98.0%, 98.1%, 90.2%) indicated low risk of impairment with optimal scores. INTERPRETATION: The HNNE is a reliable early screening tool for severe motor and cognitive impairment at 2 years corrected age in infants born very preterm. Future studies should examine individual HNNE subscales and their integration with complementary tools to improve comprehensive neurodevelopmental risk stratification.