Postpartum pleural effusion: A common radiologic finding

We did a retrospective study of 112 patients and a prospective study of 30 patients and 30 controls to ascertain the incidence of postpartum pleural effusion. An effusion was shown on chest radiographs in 51 patients (46%) in the retrospective study, and 20 patients (67%) in the prospective study. The incidence of pleural effusion in obstetric patients in the prospective study was significantly greater than that of controls (chi-squared test, 20.4, p <0.001). There was no difference between patients with effusion and those without in age, race, parity, antepartum complications, method of delivery, fetal outcome, or postpartum complications. We conclude that pleural effusion occurs frequently in the first 24 hours after delivery and that, in the absence of symptoms or signs of cardiopulmonary disorder, no intervention is necessary.