Obstetric and neonatal outcomes in severe fetal ventriculomegaly

To determine the early outcome and the incidence of associated structural anomalies in pregnancies complicated by severe fetal ventriculomegaly (VM).

A review of cases of severe fetal VM (posterior horn of lateral ventricle > 15 mm at referral or during prenatal follow-up) referred to a fetal medicine centre in Eastern England over 4 years from 2001 was made. Results of specialist prenatal investigations including ultrasound (US), karyotype, antiplatelet antibodies and congenital infection screen were noted. Neonatal clinical and cranial US findings, autopsy findings and neurodevelopmental follow-up at 4 months were obtained.

Twenty cases of severe VM were identified, including 3 with spina bifida. Median gestation at diagnosis was 28 weeks (range 16-36 weeks). Twelve cases had additional intra-cranial abnormalities and two had abnormalities outside the central nervous system. One case was complicated by toxoplasmosis. There was one case of trisomy 21. Ten pregnancies were terminated. Ten babies were live born, all of whom had VM confirmed, and two of these babies died within 4 months. Of the remaining eight, seven have abnormal neurodevelopment.

Severe VM is often diagnosed after the threshold of viability. Termination of pregnancy was requested in about half the cases owing to the risk of long-term neurodisability, and in all cases diagnosed before 24 weeks. In those live born, there was abnormal outcome in all but one.