Sometimes also called selective reduction, multifetal pregnancy reduction is a medical procedure in which a higher-order multiple pregnancy (triplets or higher) is reduced to twins or a singleton pregnancy. A recommendation for this procedure is made because the risks increase substantially when a woman carries three or more babies. It is also much more likely the pregnancy will end early — over 90 percent of triplets and virtually all higher number pregnancies end in preterm labor — and that the surviving babies will have disabilities.

The decision to undergo this procedure must be done early in pregnancy, usually before twelve weeks. The procedure involves injecting (using ultrasound as guidance) potassium chloride into one or more of the fetuses, stopping the heartbeat.

The procedure is generally performed between eleven and twelve weeks gestation. Some physicians recommend waiting as long as possible before reducing the pregnancy. This is because many multiple pregnancies experience what is called a vanished fetus, in which one or more of the fetuses are naturally reabsorbed by the mother's body and do not continue the pregnancy.

Multifetal reduction is generally considered safe and necessary in many cases. However, one of the concerns with the procedure is that there is a 6 to 8 percent chance of losing the other fetuses. The risk increases with the number of fetuses in the pregnancy.

Deciding to do a reduction is very difficult. Most often, the woman has undergone fertility treatments and worked very hard to get pregnant. The thought of reducing a pregnancy that was so difficult to achieve can be painful. It can be difficult to consider what the lost fetuses might have become. However, this procedure gives the remaining fetuses a greater chance at survival and good health. Should you find yourself in this position, talk with your doctor about the recommendation, procedure, and outlook. Each woman must weigh the risks and benefits of the procedure herself and come to her own decision.