Mild ventriculomegaly in the fetus: Perinatal and long-term outcome

Mild fetal ventriculomegaly, defined as the transverse diameter of the atrium of the lateral ventricle between 10 and 15 mm, is readily diagnosed at the routine ultrasound scan. To evaluate the significance of this finding we reviewed the literature, and 158 consecutive cases referred to our Ultrasound Unit between 1990 and 2000. Malformations of the central nervous system and/or other organs were found in about 40% of the cases (range among studies 10-76%). In these cases, the rate of aneuploidies was almost 20% (range 13-66%). When structural anomalies were ruled out, the rate of chromosomal anomalies was still high (4.5%; range 3-14%). However, if maternal age was taken into account as a risk factor, the rate decreased to 1.4%. Isolated mild ventriculomegaly has a good prognosis, with a survival rate of 97%, and a good neurodevelopmental outcome in over 90% of cases. However there are few well-documented, long-term follow-up studies, and further investigations are warranted.