Ethical issues involving multifetal pregnancies.

Selective termination is a procedure in which an anomalous fetus in a multifetal pregnancy is terminated with the intent of allowing the pregnancy to continue, so that the patient delivers one or more healthy infants at term. Multifetal pregnancy reduction is the elective reduction of three or more fetuses to a smaller number in an attempt to reduce the incidence of premature delivery in these patients. The ethical issues relating to these two procedures are quite different. Data are presented relating to the efficacy and safety of each procedure, and the ethical issues relating to them are discussed.