Are routine cranial ultrasounds necessary in premature infants greater than 30 weeks gestation?

The purpose of this study was to validate the recommendation of the American Academy of Neurology and the Child Neurology Society that screening cranial ultrasonography be performed routinely on all infants of less than 30 weeks gestation at 7 to 14 days of age and again between 36 and 40 weeks postmenstrual age, and, by using this practice parameter, to determine the number of babies with a clinically significant abnormal screening cranial ultrasound (US) who would otherwise have been missed. A retrospective study of 486 infants of 30 to 33 weeks gestation born January 1, 1999 to June 30, 2004 was done. All had screening cranial ultrasounds. Grade III and/or grade IV intraventricular hemorrhage (IVH) occurred in 4 (0.8%) infants of 30 to 31 weeks gestation. Infants with significant IVH had either risk factors for brain injury or symptoms that would eventually warrant US during their hospitalization. Seven (1.4%) infants had periventricular leukomalacia (PVL). All infants with a final diagnosis of PVL had pre- and/or perinatal risk factors associated with PVL. There was a significant trend toward fewer abnormal cranial ultrasounds from 30 to 33 weeks gestation (p = 0.04). Our study supports the recommendation by the American Academy of Neurology and the Child Neurology Society that screening US can be limited but suggests that the gestational age cut off should be 30 weeks or less.