Area of lateral ventricles measured on cranial ultrasonography in preterm infants: association with outcome. The association between measurements of lateral ventricle area (determined by serial ultrasound scans) and outcome was studied in 70 preterm neonates of 33 weeks' gestation or less. The study group was subdivided into four groups according to cranial ultrasonographic findings at 2 weeks postnatal age: group A (n = 15) had isolated periventricular/intraventricular haemorrhage; group B (n = 20) had periventricular/intraventricular haemorrhage and dilated ventricles; group C (n = 24) had periventricular/intraventricular haemorrhage and periventricular leukomalacia with or without dilated ventricles; and group D (n = 11) had isolated periventricular leukomalacia. Eighty seven preterm infants with no evidence of intracranial disease and good neurodevelopmental outcomes at 2 years formed the control group. A poor outcome was observed in infants in group B, C, and D, particularly in those who had persistent dilated ventricles at 6 weeks postnatal age and extensive periventricular leukomalacia. There was no difference in outcome between group A and controls. During the first six weeks of life ventricular area growth velocities were significantly higher in groups B, C, D, compared with normal controls and group A. We suggest that persistent ventricular dilatation at this early stage carries a bad prognosis, which is the result of atrophy of the brain. 