Postpartum pneumopericardium.

Postpartum pneumopericardium has been previously reported in only 4 patients, but it may occur more frequently than is currently recognized. Two patients are presented with pneumopericardium and pneumomediastinum with symptoms appearing on the first and second postpartum days. The second stage of labor was prolonged in both patients and associated with strenuous maternal effort. Both patients were primiparous and developed dyspnea, pleuritic chest pain, and had Hamman sign. Chest x-rays established the diagnosis in both patients. Echocardiography was nondiagnostic in one patient and mimicked pericardial effusion in the other. Although fatal tension pneumopericardium has been reported in association with other causes, the course in these 2 patients and in the other 4 reported patients has been benign. Symptoms resolved spontaneously in these 2 patients by 72 hours after their appearance. A postulated mechanism for postpartum pneumopericardium is presented.