The Red River Women's Clinic in Fargo, N.D., the only abortion clinic in North Dakota, is challenging a new state law that bans abortions as early as six weeks into pregnancy, when an unborn baby's heartbeat can first be detected.
The group filed a federal lawsuit Tuesday in an attempt to block the tough abortion restrictions from taking effect.
The lawsuit is also challenging another state law that forbids abortions because of a genetic defect, such as down syndrome.
"These laws are blatantly unconstitutional," Janet Crepps, an attorney for the Center for Reproductive Rights, told the Associated Press. "In effect, they would deny virtually all women access to abortion in North Dakota."
"If it takes effect, 90 percent of abortions would be completely banned and threaten the ability of the clinic to remain open," she said.
Critics also say the North Dakota laws are the most extreme in the nation, leading some abortion-rights advocates to believe the measures are an attempt to close the Red River Women's Clinic.
Supporters of the fetal heartbeat measure, like Gov. Jack Dalrymple, R-N.D., have said it's a challenge to the U.S. Supreme Court's 1973 Roe v. Wade ruling that legalized abortion up until a fetus is considered viable, usually at 22 to 24 weeks, according to the Associated Press.