Aim To evaluate the outcome of prenatally diagnosed isolated ventriculomegaly at University Hospitals Coventry and Warwickshire National Health Service Trust, Coventry.

Method The authors conducted a retrospective study of pregnancies diagnosed with isolated ventriculomegaly between January 1999 and 2009. Mild to moderate ventriculomegaly was defined as atrial diameter of posterior horn of lateral ventricles (Vp) measuring between 11 and 15 mm and severe ventriculomegaly as Vp >15 mm.

Results The authors identified 47 cases with ventriculomegaly from the congential malformation register and fetal medicine database. Of these, 28/47 (62%) had associated intracranial or extracranial anomalies and 18/47 (38%) had isolated ventriculomegaly. Among the cases with isolated ventriculomegaly, 10/18 (55%) of cases underwent invasive fetal testing and 2/10 (20%) had abnormal karyotype.

In the cohort with mild to moderate ventriculomegaly (14/18), there were three medical termination of pregnancies (MTOP). Among the pregnancies that continued and resulted in live births, seven cases had normal sized ventricles on follow-up antenatal scan and another four had a normal postnatal scan. Of the four cases with severe ventriculomegaly, there were three live births and one MTOP. One baby had a normal development with squint and hypermetropia, one had mild developmental delay with poor speech and sixth nerve palsy and another one is being managed expectantly.

Conclusion Our study reiterates that isolated mild to moderate ventriculomegaly in the absence of aneuploidy and negative viral screen is associated with favourable outcome. Follow-up scans (antenatal and postnatal) are useful in determining prognosis as mild to moderate cases can spontaneously regress. On the other hand the outcome is guarded in cases with severe ventriculomegaly.