Prenatal Ventriculomegaly - Diagnosis, Prognostication and Management

Fetal ventriculomegaly (VM) refers to the abnormal enlargement of one or more ventricles of the brain in-utero. The enlargement may or may not be related to ventricular obstruction and increased intracranial pressure; therefore, the term "hydrocephalus" is not used. VM is diagnosed usually in the mid-trimester when the atrial diameter (AD) of the lateral ventricle is more than 10 mm on one or both sides. A thorough workup is then required to identify the cause as the etiology is diverse. Fetal magnetic resonance imaging (MRI) may yield additional information. Serial ultrasound follow-up would be required to assess its progression with advancing gestation. The prognosis and long-term outcomes greatly depend upon the etiology, the severity at diagnosis, progression, and associations. This article reviews the definitions, diagnosis, and workup of fetal VM, discusses follow-up protocols and prognosis, and examines the role of fetal therapy, including fetoscopic surgery in its prenatal management.