Evaluation of a Cranial Ultrasound Screening Protocol for Very Preterm Infants.

Abstract

Cranial ultrasound (cUS) screening is recommended for preterm neonates born before 32 weeks' gestational age (GA). The primary aim of this study was to determine if both a day 3 and day 8 cUS screening examination is necessary for all neonates. A retrospective observational study was performed at a tertiary-level Australian hospital. Frequencies of cranial ultrasound abnormality (CUA) were compared between routine screening performed at postnatal days 3, 8, and 42. Univariate and multivariate analyses of risk factors for intraventricular hemorrhage (IVH) was performed using logistic regression. cUS examinations on 712 neonates born before 32 weeks' GA were included. Neonates were divided into 2 groups: 99 neonates in the 23-25 weeks 6 days GA (group A) and 613 neonates in the 26-31 weeks 6 days GA (group B). All CUA occurred more frequently in group A neonates and in the subset of group B neonates who had defined risk factors. Low-risk group B neonates had lower incidence of CUAs demonstrated on day 8 cUS than high-risk group B neonates, with no significant differences between day 3 and day 8. Logistic regression analysis identified a number of risk factors (vaginal delivery, small for GA, Apgar score <7 at 5 minutes, intubation, patent ductus arteriosus and infection) that were associated with increased frequency of IVH on day 8. In neonates born between 30 and 31 weeks 6 days GA, 35% had a CUA identified. Low-risk preterm neonates born between 26 and 31 weeks 6 days GA, without complications, could be screened with a single early cUS examination around day 8 without missing substantial abnormality.