A law that bans almost all abortions after six weeks has taken effect in the US state of Iowa.
The legislation allows the procedure until early signs of cardiac activity can be detected in a foetus or embryo, with exceptions in cases of rape, incest, foetal abnormalities and when the mother's life is in danger.
The Republican-enacted ban was blocked after its passage last year before being upheld by the state's highest court last month.
It is among the most restrictive policies to be enforced since Americans lost the national right to abortion access two years ago.
Before Monday, abortions were allowed through the 20th week of pregnancy in Iowa.
The US Supreme Court's 1973 Roe v Wade decision had guaranteed the right to an abortion prior to foetal viability, usually between 24 and 28 weeks, before its repeal nearly a half-century later by the court's new conservative majority.
Iowa now joins a growing list of Midwestern states, including its neighbouring Missouri and South Dakota, that have enacted restrictions since Roe's overturn.
The ban is expected to force state residents to seek care in adjacent Democrat-led states that have taken action to maintain or expand abortion access since 2022, building pressure on providers in Illinois and Minnesota.
Iowa Republicans had passed their prohibition last summer after failing in an identical effort six years ago.
The legislation hinges on what lawmakers deemed a “detectable fetal heartbeat” - a term medical groups say mischaracterises the electronic impulses that signify early cardiac development.
But a lower court temporarily blocked the ban from going into effect after providers argued in a lawsuit that it goes against Iowans' constitutional rights.
The Iowa Supreme Court disagreed and rejected the suit last month in a 4-3 ruling.
The state's Republican governor, Kim Reynolds, who signed the bill into law, hailed the top court's decision at the time as "a victory for life".
“There is nothing more sacred and no cause more worthy than protecting innocent unborn lives," she wrote in a statement.
But polls show that nearly two-thirds of Iowans believe abortion should be legal in most or all cases.
With the November general election barely three months away, Democrats are hoping to rally voters around support for abortion rights.
"This morning, more than 1.5 million women in Iowa woke up with fewer rights than they had last night because of another Trump Abortion Ban," Vice-President Kamala Harris, the party's expected presidential candidate, wrote on X, formerly known as Twitter.
Ms Harris has promised to restore reproductive rights.
Donald Trump, the Republican candidate, has said he is "proudly the person responsible" for ending Roe, arguing the issue of abortion should be decided by individual states.
Since Roe's repeal, 22 states have enacted restrictions - affecting more than one in three American women - despite their widespread unpopularity.
