Aim To study the outcome of pregnancies with prenatally diagnosed central nervous system (CNS) anomalies.

Method A retrospective review of all the fetuses diagnosed with CNS anomalies on antenatal ultrasound over a 10-year period (1999–2009) at University Hospitals Coventry and Warwickshire National Health Service Trust.

Results The authors identified 118 cases of CNS anomalies from the congenital malformation register and fetal medicine database. Of these, majority were neural tube defects (55/118, 46%), rest were isolated ventriculomegaly (18, 15%), posterior fossa anomalies (13, 11%), holoprosencephaly (12, 10%), ventriculomegaly with extracranial anomalies (12, 10%), agenesis of corpus callosum (4, 3%) and microcephaly (4, 3%). Additional intracranial or extracranial malformations were present in 49% of fetuses (58/118). Of the 22 cases that had invasive fetal testing, nine had abnormal karyotype.

Data on outcome were available for 115 pregnancies and 71% (82/115) underwent termination of pregnancy. Only 20% (24/115) resulted in live births and 16 children were reported to have normal neurological developmental (13 with isolated ventriculomegaly and 3 with callosal agenesis). Of the four survivors that developed severe developmental delay, two had microcephaly, one had porencephalic cyst and one with severe ventriculomegaly requiring ventriculoperitoneal shunt.

Conclusion Prenatally diagnosed CNS anomalies are associated with significantly high rates of termination of pregnancy (71%), which may partly explain the low rate of invasive fetal testing (22/118, 19%). Further, the predominance of neural tube defects in our study supports the case for better implementation of primary prevention by preconceptional folic acid therapy.