If it becomes law, the proposal would make Indiana the ninth state to require an ultrasound prior to an abortion, according to the Guttmacher Institute, a research group that supports abortion rights.
Senators voted 33 to 16 to approve the measure, advancing it for consideration by the state House of Representatives, which like the Senate is controlled by a Republican super-majority.
Republican Governor Mike Pence, a former U.S. congressman who strongly opposes abortion and championed federal attempts to cut off funding for abortion provider Planned Parenthood, is expected to sign the bill into law if it reaches his desk.
The bill, as first introduced by Republican state Senator Travis Holdman, would have required two ultrasounds before a woman could obtain a prescription for the abortion pill, officially known as RU486. It was amended to allow the doctor providing the drug to decide if a second exam was needed.