BISMARCK, N.D. (AP) — Attorneys representing North Dakota's only abortion clinic asked a federal judge Friday to permanently block a law that bans abortions when a fetal heartbeat is detected, saying it would outlaw most abortions in the state.

The New York-based Center for Reproductive Rights is representing Fargo's Red River Women's Clinic in a lawsuit challenging the law passed last year by the North Dakota Legislature. It outlaws abortions as early as six weeks into pregnancy — before many women know they're pregnant.

"We're quite confident the judge will find this ban unconstitutional and that it is so blatantly in violation of Roe v. Wade and 40 years of Supreme Court precedent that he will rule in our favor," David Brown, one of the attorneys representing the clinic, said after the hearing.

U.S. District Judge Daniel Hovland in Bismarck said he will rule in the coming weeks on whether to make permanent the temporary injunction that he granted in July. If not, the case will go to trial.

During arguments Friday, attorneys representing the state argued vitality begins at conception and a heartbeat historically signifies life.

Dan Gaustad, one of the attorneys representing the state, argued the law in question protects women, noting that the state has heard from women who were adversely affected by abortions.

The statute in question, Gaustad said, "protects the lives of unborn children; it protects the health of women."

Gaustad argued the fetal heartbeat law offers a legitimate challenge to the U.S. Supreme Court's 1973 Roe. v. Wade ruling that legalized abortion up until the point of viability, or when a fetus viably could be expected to survive outside the womb. That is typically at 22 to 24 weeks.

"We're going to be challenging the very underpinnings of Roe v. Wade," the attorney said in court Friday.

The law in question was one of four that the Republican-controlled Legislature passed and GOP Gov. Jack Dalrymple signed last year that combined to make North Dakota the most restrictive state in the nation in which to get an abortion.