Unusual evolution of a pericardial mass diagnosed by fetal echocardiography.

An intrapericardial mass with a pericardial effusion was diagnosed by ultrasound examination in the fetus of a 29-year-old gravida 1 para 0 woman at 32 weeks' gestation. Serial in utero examinations showed disappearance of the pericardial effusion at 35.5 weeks' gestation, while the mass remained unchanged. Vaginal delivery ensued at 39 weeks. Clinical and echocardiographic examination of the newborn revealed normal cardiac anatomy with no abnormal mass or pericardial effusion. Follow-up examinations confirmed these normal data.