Under current law, abortion is legal in Iowa until the 20th week of pregnancy. The new law struck down on Tuesday was among the strongest abortion regulations in the country.
State Sen. Janet Petersen of Des Moines, the Democratic minority leader, said the law was "extreme" and should have been overturned "because it restricted the freedom of Iowa women and girls to care for their bodies, and it forced motherhood on them."
Last year the Ohio legislature passed a similar bill banning abortion based on fetal heartbeat, but failed to override Gov. John Kasich veto. Kasich's successor, also a Republican, has voiced support for the bill.
The first heartbeat-based abortion ban was passed in 2013 by the Arkansas legislature, which also voted to override a governor's veto of the bill.. The U.S. Court of Appeals for the Eighth Circuit ruled it was unconstitutional and the U.S. Supreme Court declined to hear an appeal.
South Carolina, Kentucky, and Missouri could consider heartbeat abortion bans this year.
The law also banned all persons from knowingly acquiring, providing, transferring, or using fetal remains in Iowa. This did not apply to medical diagnostic samples, or forensic investigations, or to fetal body parts donated for medical research after a miscarriage or stillbirth. It is unclear whether those provisions still apply.
Iowa Gov. Kim Reynolds signed the bill into law May 4, 2018.
"I believe that all innocent life is precious and sacred, and as governor, I pledged to do everything in my power to protect it. That is what I am doing today," she said at the time. Reynolds said she felt it was "immoral to stop an innocent beating heart," as well as "sickening to sell fetal body parts."
The Republican governor acknowledged the near certainty that the law would face court challenges, claiming her actions were "bigger than just a law," and that she will not back down.
Catholic bishops of the state had voiced qualified support for the bill's intentions.
"We support the life-giving intent of the provisions in the bill and we want to do everything we can to support that," Bishop Walker Nickless of Sioux City, Iowa, told CNA in a May 2018 interview before the bill was signed into law.
(Story continues below)
Subscribe to our daily newsletter
He voiced hope that the bill could halt some trafficking of fetal body parts following an abortion.
Iowa's bishops recognized that some provisions of the bill might not withstand judicial scrutiny.
Bishop Nickless added that Catholics might disagree about the strategy of supporting legislation that could be overturned by courts. He encouraged creative pro-life advocacy, saying Catholics should discern such questions carefully. He said the message of the state's bishops had been: "If you're a Catholic and your conscience tells you to support this, please do."
Nickless reaffirmed that the Catholic Church supports the health and rights of all women, including those in the womb. "If we are talking about women we need to make sure we are talking about unborn females as well, and protecting them," he said.