Cerebral biometry at birth and at 4 and 8 months of age. A prospective study using US

Although longitudinal reference intervals for ventricular size are crucial for the diagnosis of dilated ventricles, such data are sparse.To establish references for ventricular measurements at birth, and at 4 and 8 months follow-up, and to examine the inter-observer variation of the measurements.This prospective, longitudinal study included 120 term newborns (boys 65, girls 55), mean age 1.5 days on initial scans, with re-examination at 4 months and 8 months of age. One examiner performed all the examinations, measuring: ventricular index, frontal horn width, third ventricle width, frontal subarachnoid space depth, optic nerve sheath diameter and resistive index.One hundred eight (90%) and 90 (75%) of the infants, respectively, attended for follow-up at 4 and 8 months of age. All measures increased with age, except for the depth of the subarachnoid spaces that showed an initial rise, followed by a mild drop at 8 months, and for the resistive index that remained stable at 0.6. The increase was particularly significant for frontal horn width with an increase from 2.2 mm at birth to 6.5 mm at 4 months in boys, and 2.1-5.8 mm in girls. The agreement between two observers was fair to moderate for most of the measurements.The increase in the width of the frontal horns between birth and 4 months of age, as well as the wide normal range found among all three age groups are noteworthy and should inform future diagnostics.