What is Ventriculomegaly?


Ventriculomegaly is also called Hydrocephalus. It is due to swelling of lateral ventricle, the part of the brain where the normal ‘brain water’ (cerebrospinal fluid) flows. Usually the right and the left lateral ventricles could be equally affected.

Why ventriculomegaly occurs?

In 90 per cent of the cases, there is no cause found. Such babies are normal in their development after birth. However, in four per cent of such cases, the chromosomes (genetic makeup) are abnormal. The commonest cause is Down Syndrome. In the minority there may be bleeding in the baby’s brain, infection or abnormal development of the brain that cause the swelling of the lateral ventricles. Interestingly, a baby boy is more affected than a baby girl by three folds. Luckily though, they are usually in the group where the development is normal and no serious cause is found.

How is this condition detected?

Usually it is by ultrasound scan. Sometimes it is suspected when the maternal serum screening is done to see the risk of chromosomal abnormality. If this is the case, then prenatal diagnosis such as amniocentesis is necessary to confirm the chromosomes of the baby. If the chromosome analysis is normal, then a detailed assessment of the baby’s body structures is important. The Foetal Anomaly Scan and Foetal Echo are performed to assess carefully each body’s organ to look for soft and hard markers. The more abnormalities are found the more sick the baby is. About four per cent of ventriculomegalic babies also have other structural abnormalities. Serial ultrasound scans are important to monitor the progress of this swelling. About 30 per cent would resolve completely. Majority of the rest would remain the same. Only a minority would become worse.

How should ventriculomegalic babies be delivered?

If the condition is only mild and the baby is normal chromosomally, vaginal delivery is allowed provided there is no other obstetric indication. If the condition is moderate and the head size is bigger than normal, an elective Caesarean Section is advisable. Of course, the most severe cases where the outlook is very poor, the unborn baby may demise while in the womb.

Should the baby need extra care after birth?

If the baby is noted to be normal prior to birth, he or she is likely to develop normally. However, the baby would need to be followed up regularly by the paediatrician till six years of age to detect any developmental delay. Those with moderate or severe condition would of course be cared for by expert neurologist or paediatrician.