Mild Cerebral Ventriculomegaly in Fetuses: Characteristics and Outcome

BACKGROUND: A fetal ultrasonographic (US) finding of mild ventriculomegaly (MVM) is not uncommon, but its prognostic significance is not clearly defined. OBJECTIVE: To evaluate the clinical and US characteristics and outcome of fetuses with mild dilatation of the cerebral lateral ventricles. PATIENTS AND METHODS: We reviewed the medical records of 34 consecutive fetuses with US evidence of MVM (atrial width of the lateral ventricles = 10-15 mm) at 18-35 weeks of gestation. RESULTS: Of the 34 fetuses with MVM, 7 underwent karyotype examination and were normal. In 4 of the 34 fetuses the pregnancy was terminated (at autopsy: 1 was normal, 2 had hydrocephalus and for 1 the parents refused autopsy). Eight fetuses that were delivered had congenital malformations; 3 of them died during the early neonatal period. In 6 of the 8 fetuses with malformations, karyotypes were available and 3 had chromosomal aberrations (trisomy 18, 45XO, and triploidy 69XXX). Spontaneous in utero resolution of the MVM occurred in 10/30 (33.3%) of the cases. Of the 26 infants that remained in follow-up, 16 (61.1%) were normal at 1 month and at 2 years of age. CONCLUSIONS: Our data confirm those of previous reports as to the characteristics and outcome of MVM. In the setting of mild fetal ventriculomegaly with a normal karyotype and an absence of malformations, the outcome appears to be favorable.