CHARLESTON, SC, May 17 (Reuters) - The South Carolina legislature on Tuesday passed a bill banning most abortions after 19 weeks of pregnancy unless the mother's life was at risk, making it the 17th U.S. state to approve such a ban.

The bill will head to Republican Governor Nikki Haley's desk, who indicated in March that she would likely sign the legislation.

Her office could not be immediately reached for comment.

The act, proposed last year in South Carolina's Republican-controlled legislature, passed after it was stripped of exceptions for pregnancies that result from rape or incest. The Senate had approved the bill in March.

Sixteen other states have passed similar laws as conservatives seek to chip away at the U.S. Supreme Court's landmark 1973 Roe v. Wade decision to legalize abortion. Courts have overturned the bans in three states.

"I believe that life begins at conception and every step we can take to get back to that point is important," the bill's sponsor, Republican Representative Wendy Nanney, said in a phone interview. "In my view and many others it's inhumane to subject that baby to pain at 20 weeks."

Critics have said the name of the Pain Capable Unborn Child Protection Act goes against medical evidence showing that a fetus at 20 weeks cannot feel pain.

"This is a dangerous bill for South Carolina women ..., made even more extreme by removing exceptions for victims of rape and incest," Alyssa Miller, South Carolina director of public affairs for Planned Parenthood South Atlantic, said in a statement.

"The reality is that abortion later in pregnancy is extremely rare and often takes place in complex and difficult situations where a woman and her doctor need every medical option available," Miller said.

(Reporting by Harriet McLeod in Charleston, South Carolina; Editing by Curtis Skinner and Richard Chang)