ObjectiveTo determine whether transabdominal selective termination of one or more abnormal fetuses in a multifetal pregnancy with dichorionic placentation is a safe and effective procedure.MethodsOne hundred consecutive selective termination procedures were performed by transabdominal injection of potassium chloride into the heart or umbilical vein of an anomalous fetus in a multifetal pregnancy. All of the abnormal fetuses were presumed to have dichorionic diamniotic placentas, based on an ultrasound evaluation before the procedure. Follow-up data were obtained for each patient regarding the development of postprocedural complications, laboratory or clinical evidence of a coagulopathy, maternal or neonatal morbidity, gestational age at delivery, and birth weight of the infants.ResultsNinety-one sets of twins were reduced to single-tons, six sets of triplets were reduced to twins, two sets of triplets were reduced to singletons, and one set of quadruplets was reduced to triplets. The anomalous fetus or fetuses were identified correctly and terminated in each case. Three patients spontaneously aborted, and one woman electively terminated her pregnancy 2 weeks after the procedure. The mean gestational age at delivery of the 96 patients who delivered surviving infants was 36.8 weeks, and 85.4% delivered at 32 weeks or later. Three women developed laboratory evidence of a coagulopathy, but there were no cases of clinically evident disseminated intravascular coagulation.ConclusionThis procedure, performed at a single institution by a small number of operators using a common protocol, accomplished its objective in all cases, was accompanied by a low spontaneous loss rate, and resulted in the birth of healthy infants at or near term in the vast majority of cases. This series suggests that selective termination is a reasonable option to consider when one abnormal fetus is found in a multifetal pregnancy with dichorionic placentation.