Iowa's Republican-controlled legislature passed the most restictive abortion ban in the US.
The decision outlaws the procedure after a foetal heartbeat is detected. This can be as early a six weeks.
The Senate voted 29-17 to pass the House of Representatives-approved bill.
It now goes to Republican governor Kim Reynolds, an opponent of abortion. She has not said publicly whether she will sign it into law.
What would the law require, if it is approved?
Any woman seeking an abortion will have to have an ultrasound to screen for a foetal heartbeat.
If one is detected, healthcare providers are barred from performing an abortion.
Among the few exceptions are if the woman was raped or a victim of incest and has reported it to the authorities.
The bill would ban most abortions in the state.
Activists on both sides of the abortion divide say the legislation is aimed at triggering a challenge to Roe v.Wade. That is the US Supreme Court's 1973 landmark decision establishing that women have a constitutional right to an abortion.
Abortion opponents say they aim to land cases back in front of the nation's top court. A 5-4 conservative majority could sharply curtail abortion access or ban it outright.
Spokeswoman Becca Lee of Planned Parenthood of the Heartland, which supports access to abortion, called the ban "intentionally unconstitutional on 99 percent of safe, legal abortion, designed to challenge Roe v.Wade."
Are any other states planning legislation like this?
Yes. In March, Mississippi's Republic governor signed into law a bill banning abortion after 15 weeks with some exceptions. This sparked an immediate court challenge by abortion rights advocates.
A similar court challenge is underway in Kentucky, which in April enacted a ban on a common abortion procedure from the 11th week of pregnancy.
What they are saying
"We created an opportunity to take a run at Roe v.Wade - 100 percent," - Republican state Senator Rick Bertrand of Sioux City says the legislation is designed to be "thrust into the court" that has become more conservative since the appointment of Justice Neil Gorsuch.
"The bill weaponises foetal heartbeat, which is, by all accounts, an arbitrary standard that bans abortion long before the point of foetal viability,"- Becca Lee.