Louisiana joins Mississippi, Ohio, Georgia, Kentucky and Missouri, which have all passed so-called "heartbeat" bills this year. Along with Alabama's near-total ban on abortion, the heartbeat bills are part of a conservative nationwide push to bring a Supreme Court challenge to the landmark 1973 Roe v. Wade ruling that legalised abortion in the US, CNN reported.
The Louisiana measure, which Democratic Governor John Bel Edwards says he will sign, passed the state House on Wednesday in a 79-23 vote and would "prohibit the abortion of an unborn human being with a detectable heartbeat", which can come as early as six weeks into a pregnancy, before many women know they are pregnant.
The bill would require an ultrasound prior to an abortion and subject doctors who perform abortions after a heartbeat is detected with a $1,000 fine or up to two years in prison.
The bill does not make exceptions for instances of rape or incest.
Democratic state Representative Ted James introduced an amendment to include those exceptions, arguing that "we are not that important to make that decision for a woman who's been raped", but the move failed 35-67.
The bill would allow for abortions preventing a pregnant woman's death or "serious risk of the substantial and irreversible impairment of a major bodily function", and would require doctors who perform abortions under such circumstances to specify their eligibility in writing.
Abortions on "medically futile" foetuses that would not survive past birth are also not subject to the restrictions.
The bill was introduced by Republican state Representative Valarie Hodges, who called it "a very solemn responsibility", reports CNN.
Meanwhile, Planned Parenthood President Leanna Wen slammed the lawmakers for joining other states that have moved to restrict abortion access.
"By passing this extreme abortion ban today, anti-women's health politic in Louisiana voted to join their counterparts in places like Alabama, Ohio, Mississippi, Missouri, and Georgia to devastate the health and well-being of women and families," she said in a statement on Wednesday. "Banning abortion will not stop abortion but it will end access to safe, legal abortion care."
Alanah Odoms Hebert, executive director of the American Civil Liberties Union of Louisiana, called the bill "plainly unconstitutional".
( With inputs from IANS )