Reduction of pleural effusion by OK-432 in a fetus complicated with congenital hydrothorax

A 29-year-old, primiparous woman was referred to our hospital at 21 weeks of gestation because of right pleural effusion in the fetus shown by routine ultrasonographic examination. Cytology revealed abundant lymphocytes, suggesting chylothorax. We removed the pleural effusion and injected OK-432 into the chest cavity at 24 and 25 weeks of gestation. Pleural effusion declined and an adhesion between the lung surface and the pleural membrane seemed to form. At 33 weeks of gestation, a female infant was born by cesarean section (1,090 g and Apgar score 6/8). Although she demonstrated slight retraction and tachypnea, management could be achieved by administration of oxygen alone without mechanical ventilation. Later, the baby was diagnosed as suffering from the Cornelia de Lange syndrome with characteristic features. OK-432 injections could thus prevent complications of chylothorax and hypoplastic lungs, without injury to either the baby or the mother.