Prenatal indomethacin toxicity in one member of monozygous twins; a case report.

A mother, treated with indomethacin because of premature labour, delivered a pair of monozygous twins at a gestational age of 33 weeks. Because of foetal transfusion syndrome, the first twin was polycythaemic and the second anaemic. The latter was also hydropic, suffered from anuria requiring peritoneal dialysis, and showed signs of severe pulmonary hypertension, probably as a consequence of intra-uterine constriction of the ductus arteriosus. The possible interaction between foetal transfusion syndrome, anuria, premature constriction of the ductus arteriosus and the prenatal administration of indomethacin is discussed. In general, indomethacin should cautiously be used as a tocolytic agent.