The strictest abortion law in the United States, banning the operation as early as six weeks into a pregnancy, has been signed into force.
Supporters said the North Dakota law, which forbids abortion if is there is any trace of a foetal heartbeat, is a direct challenge to a US Supreme Court landmark ruling, Roe v Wade, that legalised abortion up until a foetus is considered viable, usually at 22 to 24 weeks.
"Although the likelihood of this measure surviving a court challenge remains in question, this bill is nevertheless a legitimate attempt by a state legislature to discover the boundaries of Roe v Wade," governor Jack Dalrymple .
The law also is an attempt to close the rural state's only abortion clinic, the Red River Women's Clinic in Fargo. Its director Tammi Kromenaker called the legislation "extreme and unconstitutional." Minutes after the governor signed the anti-abortion measures, unsolicited donations began pouring into the clinic to help opponents prove the new laws are unconstitutional.
Abortion-rights advocates have promised a long legal fight that they say the state cannot win.
North Dakota politicians also moved last week to outlaw abortion in the state by passing a resolution defining life as starting at conception, essentially banning abortion in the state. The measure is likely to come before voters in November 2014.
Mr Dalrymple also signed into law other measures that make the state the first to ban abortions based on genetic defects such as Downs syndrome and require a doctor who performs abortions to be a physician with hospital-admitting privileges. The measures also ban abortion based on genetic selection.
Doctors performing an abortion after a heartbeat is detected could face a felony charge punishable by up to five years in prison and a 5,000 dollar fine. Women having an abortion would not face charges.
Ms Kromenaker said Mr Dalrymple "awoke a sleeping giant" by approving the measures.
"First and foremost, abortion is both legal and available in North Dakota," she said. "But anytime abortion laws are in the news, women are worried about access."