Prenatal ultrasonographic diagnosis of fetal hydrocephalus due to infection with parainfluenza virus type 3.

Parainfluenza virus type 3 is one of the most common causes of respiratory infection in infants. No complications of pregnancy or fetal anomalies have been reported in association with parainfluenza virus infection. A pregnancy was terminated at 22 weeks' gestation due to ultrasonographic diagnosis of hydrocephalus. Pathological examination was consistent with viral encephalitis, ventriculitis and pneumonia. Serological investigation demonstrated a significant rise in maternal antibody titers for parainfluenza virus type 3. Parainfluenza virus type 3 may be associated with severe fetal infection in the first half of pregnancy. Serological studies for this virus should be considered in cases of fetal hydrocephalus.