At least for now, the litigants are not challenging a separate ban on abortions after 20 weeks of pregnancy that also is part of the measure.

Rita Bettis, ACLU of Iowa legal director, said the lawsuit was filed now because the new abortion law would take effect immediately upon Branstad signing it at a ceremony set for 8:30 a.m. Friday at the state Capitol.

Opponents of the measure said that means the law would immediately interrupt the appointments — and lives — of women already scheduled to have abortion procedures.

“This reckless, immediate effective date will throw the lives of women and medical services in Iowa into a state of chaos,” Bettis told a news conference Wednesday.

Some of the affected women are likely to be very near the point in their pregnancy at which they can no longer use medication abortion, she noted. As a result, they would be forced to decide between having a surgical procedure or being stopped from accessing a legal abortion, she said.

“This abortion restriction takes us back decades,” said Suzanna de Baca, leader of Planned Parenthood of the Heartland. “It is among the harshest in the nation and will strip access away from the most vulnerable women who need abortion care.”