Intrauterine cytomegalovirus infection presenting as fetal meconium peritonitis.

Recent reports have suggested that focal hyperechoic abdominal masses detected during the second trimester may represent a normal variation in fetal intestinal development that is transient in nature and not associated with pathologic conditions. The patient described here had second-trimester ultrasonic findings of fetal meconium peritonitis without ascites, polyhydramnios, or other anomalies. Subsequent ultrasound examinations at 22, 30, and 36 weeks demonstrated no change in the abdominal appearance. At birth, this preterm male infant had clinical symptoms of congenital cytomegalovirus infection confirmed by viral culture and serologic studies. Retrospective studies of maternal serum obtained early in the second trimester confirmed a primary cytomegalovirus infection 4 weeks before the initial ultrasound examination. Although fetal hydrops and ascites have occasionally been associated with intrauterine cytomegalovirus infection, fetal meconium peritonitis has not been previously recognized in patients with congenital cytomegalovirus.