From the Research
Mild ventriculomegaly in a fetus is associated with an increased risk of seizures after birth, with a risk of approximately 5-10% for postnatal seizures, as indicated by the most recent and highest quality study 1. When a fetus is diagnosed with mild ventriculomegaly, typically defined as lateral ventricles measuring 10-15mm, the risk of seizures varies depending on whether the ventriculomegaly is isolated or accompanied by other brain anomalies. The connection between mild ventriculomegaly and seizures stems from the fact that enlarged ventricles may indicate disrupted neuronal migration, cortical malformations, or other subtle brain developmental issues that predispose to abnormal electrical activity in the brain after birth. Key points to consider include:
- The risk of seizures is substantially higher when ventriculomegaly occurs with other brain or genetic abnormalities, with seizure risk potentially increasing to 15-25% in these cases 2.
- Parents of infants born after prenatal diagnosis of ventriculomegaly should be educated about seizure recognition and first aid, though no prophylactic antiepileptic medication is recommended without actual seizure occurrence.
- The underlying mechanism involves potential disruption to normal neuronal connectivity and brain circuit formation during critical developmental periods, which creates susceptibility to abnormal electrical discharges that manifest as seizures after birth. It is essential to note that the prognosis is determined by the severity of ventriculomegaly and/or the presence of co-existing abnormalities, and a multidisciplinary fetal neurology team can provide parents with the most thorough prenatal counseling 1.