A Senate bill banning a rarely used, late-term abortion technique is headed back to the House for reconciliation. The Senate approved the legislation, the first to outlaw an abortion technique since the Supreme Court's 1973 Roe vs. Wade decision made abortion legal, on a 54-44 vote. Opponents say the procedure involves killing a fetus before it is pulled from the birth canal. Doctors describe it, however, as the least risky technique for a mother who has a compelling medical reason to terminate a late-term pregnancy. "The important thing that gets distorted in this debate is that these are extremely rare procedures," says TIME's Wendy Cole. "They are performed at only three facilities in the U.S., and only about 500 of them are performed each year. This is not an elective procedure. It is only done in cases where the fetus has a lethal anomaly or if the woman's life is endangered."