Iowa Gov. Kim Reynolds (R) on Friday afternoon signed into law the Fetal Heartbeat Bill, which prohibits doctors from performing an abortion after the detection of the baby’s heartbeat.

The law would require any women seeking an abortion to undergo an ultrasound to determine whether a fetal heartbeat can be detected, a milestone usually detected around the sixth week of pregnancy. The legislation does make some exceptions for pregnancies conceived through rape or incest, as well as fetal abnormality, or if a doctor determines that a woman’s life is in danger.

It would also ban all persons from knowingly acquiring, providing, transferring, or using fetal remains in Iowa. This would not apply to medical diagnostic samples, or forensic investigations, or to fetal body parts donated for medical research after a miscarriage or stillbirth.

Previously, abortion was legal in Iowa until the 20th week of pregnancy. The new law is the strongest abortion regulation in the country.

The bill passed through the Iowa House of Representatives on Tuesday by a vote of 51-46, and passed the Senate on Wednesday by a vote of 27-19. The bill has been significantly controversial in the state, and there have been many protests.

In a statement published on the governor’s website, Reynolds said she signed the bill as she felt it was “immoral to stop an innocent beating heart,” as well as “sickening to sell fetal body parts.”

“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. She credited her faith as the force that “leads her to protect every Iowan, no matter how small.”

The law will most certainly be challenged in court, and is unlikely to go into effect without approval from the Supreme Court. Acknowledging this, Reynolds said that her actions on Friday were “bigger than just a law,” and that she will not be backing down.

Planned Parenthood and the ACLU promised a lawsuit against Reynolds before she signed the bill, criticizing the governor for signing a bill they say is “so clearly unconstitutional.”

If this bill is taken to the Supreme Court, it could potentially force the justices to reconsider the 1973 Roe v. Wade decision that established a constitutional right to abortion.

Jeanne Mancini, president of March for Life, praised the law, saying it “will not only save lives, it also reminds us that abortion stops a beating heart.”

“We thank Iowa for recognizing that every life is a gift and that personhood has inherent dignity from the moment of conception,” she said.