Day 1 Cranial Ultrasonography Detects Prenatal Brain Abnormalities in Preterm Infants: A Retrospective Cohort Study

BackgroundCurrent guidelines recommend cranial ultrasonography (CUS) screening at 7-14 days for infants <30 weeks of gestation. However, emerging evidence suggests that significant prenatal brain injuries may be missed by delayed screening protocols.ObjectiveTo evaluate the diagnostic yield of day 1 CUS in identifying prenatal brain abnormalities across all preterm gestational ages.MethodsRetrospective cohort study of 365 preterm infants (24.0-36.6 weeks of gestation) who underwent CUS within 24 hours of birth at a tertiary neonatal intensive care unit (June 2014-July 2020). CUS findings were analyzed by gestational age groups, with particular attention to signs of prenatal hemorrhage and white matter abnormalities. Images were independently reviewed by 2 board-certified neonatologists with consensus review for discordant cases.ResultsDay 1 CUS revealed pathologic findings in 141 of 365 infants (38.6%), with gestational age-dependent prevalence: 44 of 69 (63.8%) extremely preterm (24-30 weeks), 53 of 129 (41.1%) very preterm (30.1-33.6 weeks), and 44 of 167 (26.3%) moderate to late preterm (34-36.6 weeks). Intraventricular hemorrhage (IVH) occurred in 58 of 365 infants (15.9%), with 31 of 58 cases (53.4%) showing clot liquefaction suggestive of prenatal onset. Critically, 14 of 58 IVH cases (24.1%) completely resolved on follow-up imaging. White matter lesions were identified in 49 of 365 infants (13.4%), demonstrating marked gestational age dependence: 25 of 69 (36.2%) extremely preterm, 23 of 129 (17.8%) very preterm, and 1 of 167 (0.6%) moderate-late preterm infants.ConclusionsDay 1 CUS identifies findings suggestive of prenatal brain pathology across all preterm gestational ages. Nearly one-quarter of early IVH cases resolve before conventional screening times. These findings suggest that earlier CUS may warrant further evaluation as a potential adjunct to current protocols; however, prospective studies with neurodevelopmental follow-up are needed before any change to screening practice can be recommended.