Diagnosis and management of unilateral third-trimester hydrocephalus: a multidisciplinary approach.

Hydrocephalus is a pathological increase in cerebrospinal fluid. This condition may occur when production exceeds absorption. Prior reports describe prenatally diagnosed unilateral hydrocephalus with varying outcomes depending on underlying brain abnormalities, karyotypic abnormalities, and infection. Prenatal ultrasound is a valuable diagnostic tool in the identification of hydrocephalus. Obstacles such as near-field artifact, additional intracranial abnormalities, fetal positioning, and maternal habitus often make the diagnosis difficult. Antenatal diagnosis is important for emotional preparation and for transfer to a tertiary center where appropriate facilities and subspecialists are available. We present a case of right-sided hydrocephalus and mild left-sided ventriculomegaly diagnosed in the third trimester. Fetal brain magnetic resonance imaging confirmed the sonographic diagnosis, which allowed the multidisciplinary fetal team to meet with the patient and formulate a management plan prior to delivery.