UPDATE, February 19, 7:46 a.m.: Iowa Gov. Kim Reynolds (R) on Monday said she would not appeal a court ruling striking down the GOP’s “fetal heartbeat” ban, the Des Moines Register reports.

Reproductive rights advocates on Tuesday filed a lawsuit in state court challenging an Iowa law they allege amounts to a total abortion ban, arguing the law violates the Iowa Constitution. 

Iowa’s so-called heartbeat ban (SF 359) prohibits doctors from performing abortions after a fetal heartbeat is detected, which can be as early as six weeks’ gestation and before many people even know they’re pregnant.

The law contains a narrow exception in cases where a person’s life is endangered by the pregnancy, and for cases of rape and incest. Cases of rape must be reported to a law enforcement agency, a public or private health agency, or family physician within 45 days. Cases of incest must be reported to a law enforcement agency, a public or private health agency, or a family physician within 140 days.

The law contains certain ultrasound requirements, though Tuesday’s lawsuit only challenges the heartbeat ban portion of the law.

At six weeks’ gestation, there is no heart, there’s no heartbeat, and there’s no fetus. There is a “fetal pole,” a thick area alongside the yolk sac that extends from one end of an embryo to the other. What can be measured at six weeks is electrical activity in the fetal pole.

The ACLU of Iowa and Planned Parenthood Federation of America are filing the lawsuit as co-counsel on behalf of Planned Parenthood of the Heartland and Dr. Jill Meadows, an OB-GYN and Planned Parenthood of the Heartland medical director. The Emma Goldman Clinic of Iowa City, an abortion provider, is also a co-plaintiff in the case. The lawsuit asserts only state constitutional claims, not federal.

“This abortion ban is beyond extreme,” Rita Bettis, legal director for the ACLU of Iowa, said in a statement announcing the lawsuit. “With it, Iowa politicians have tried to ban virtually all abortions for women in our state. In the 45 years since Roe, no federal or state court has upheld such a dangerous law.”

“Today, we’re fighting back in court for every person’s individual rights and freedoms, which go to the heart of who we are as a country,” Dawn Laguens, executive vice president of Planned Parenthood Federation of America, said in a statement. “Enough is enough. Gov. Kim Reynolds has no right to impose her beliefs on Iowa women. We will not back down until every person has the freedom and opportunity to make the health care decisions that are best for them and their families.” 

In 2015, the U.S. Court of Appeals for the Eighth Circuit stymied nearly identical measures passed by Republicans in Arkansas and North Dakota. The U.S. Supreme Court refused to take up both cases, leaving the laws permanently blocked.

Iowa Republicans’ total abortion ban is slated to take effect July 1. Iowa Attorney General Tom Miller (D) announced on Tuesday that his office would not defend the ban in court and suggested another group step in.