"I believe in exceptions for rape, incest and life of the mother, and that's what I've voted on," House Minority Leader Kevin McCarthy, a California Republican, said on Thursday, becoming the highest-ranking GOP official to object to the latest wave of sweeping anti-abortion laws from conservative states.

Alabama this week approved a law to ban abortion at any stage of pregnancy, with no exceptions for rape or incest.

That came on the heels of laws in other states - including Ohio, Kentucky and Mississippi - that ban the procedure when a fetal heartbeat is detected, at about six weeks of pregnancy, also with no exceptions for rape or incest. All of the legislation includes exceptions for abortions to preserve a woman's life.

Republican politicians in Alabama and elsewhere have said their goal is to give the Supreme Court's conservative majority an opportunity to reverse the 1973 Roe vs Wade decision, which legalised abortion nationwide.

The bans have activated the 2020 Democratic presidential candidates and other prominent Democrats in opposition. But some Republicans in Washington also say they oppose new abortion restrictions that don't allow for the rape and incest exceptions.

Even Alabama's GOP senator said he supports the three traditional exceptions.

Senator Richard C Shelby said he "always supported" exceptions for rape and incest.

"I'm not down there," he said of his home state's most recent law.

The latest anti-abortion legislation represents a new front in the abortion debate. Nationally, Republicans have supported exceptions for all three circumstances for many years.

The laws in all four of the states - Alabama, Kentucky, Mississippi and Ohio - are being challenged in court or have already been struck down.

Missouri's state Senate approved a bill on Thursday to prohibit abortion at eight weeks of pregnancy with no exceptions for rape or incest. It is expected to be taken up by the state's House.

Australian Associated Press