Fatal systemic air embolism in a neonate with absent aortic valve.

A 32-year-old pregnant woman was referred at 33 weeks' gestation for prenatal ultrasound demonstrating fetal hydrops due to absent aortic valve with free aortic valve insufficiency. Elective caesarian section at 34 week's gestation was performed. Surgical intervention was planned immediately after labor at which time mitral valve closure and atrial septostomy using cardiopulmonary bypass would be performed. However, before insertion of the cannula for cardiopulmonary bypass, a gush of air from the right atrium was noted. The surgical procedure was abandoned because systemic air embolism was suspected. The child died 2 h after birth. Autopsy showed absent aortic valve with closed foramen ovale and left-ventricular hypertrophy. Microscopic findings showed pulmonary and systemic lymphangiectasis, which caused the introduction of air into systemic venous system by way of lymphatic duct just after birth.