Difference between left and right lateral ventricular sizes in neonates.

The objective of this study is to determine the causes of asymmetry of the lateral ventricles in neonates. We also studied the effect of head position and the relationship of body weight at birth in regard to lateral ventricular size. Eligible for inclusion in this study were 60 neonatal infants whose gestational age was 33.1+/-3.5 weeks and whose birth weight was 1793+/-613 g. Ultrasonographic examinations were performed at the first and the second weeks after birth. In parasagittal and coronal scans through the posterior horn of the lateral ventricle, the lateral ventricle was traced and its area was measured. We found no significant variation of ventricular size in relation to body weight at birth. The left ventricular size was larger than the right one. The difference of the left and right ventricular sizes was partially effected by head position. The ratio of left to right lateral ventricular sizes showed a very wide distribution. We considered that ventricular asymmetry is not pathological, but due to individual differences.