Ductus arteriosus aneurysm with massive thrombosis of pulmonary artery and fetal hydrops.

Ductus arteriosus aneurysm (DAA) is a rare cardiovascular lesion usually diagnosed within the first 2 months of life, or less frequently in the 3rd trimester, by antenatal sonography. The true in utero incidence of DAA is unknown, as most affected fetuses are asymptomatic at birth. Potential complications include thromboembolism, rupture, and death. We report a unique lethal case of a large DAA detected by mid-2nd trimester fetal echocardiography, complicated by stricture and massive occlusive thrombosis extending into the pulmonary artery branches. Stricture and thrombosis of the DAA led to interruption of fetal circulation, cardiac failure, and fetal hydrops, ultimately resulting in fetal demise.