The Iowa Supreme Court ruled on Friday that the state’s six-week abortion ban could be enforced, a decision that sharply limits access to the procedure and fulfills a longstanding aim of the state’s Republican leaders.

The 4-to-3 ruling vastly limited the time frame for legal abortions in Iowa — the previous standard was 22 weeks — and meant that many women may travel to nearby states like Illinois or Minnesota to undergo the procedure. For Iowa Republicans, the decision marked the realization of a long-held policy goal and vindication after previous setbacks in the courts. For Democrats, it was a painful reminder of how much political ground they have lost in Iowa and, they hoped, an election-year warning to voters across the country that Republicans would continue trying to limit abortion in places where they win power.

“There is no right more sacred than life, and nothing more worthy of our strongest defense than the innocent unborn,” Gov. Kim Reynolds, a Republican, said in a statement, adding that “I’m glad that the Iowa Supreme Court has upheld the will of the people of Iowa.”

State Senator Pam Jochum, her chamber’s Democratic leader, called it “a tragic day in Iowa history.”

“This despicable and dangerous ruling cannot be the last word on reproductive rights and personal freedom in Iowa,” she said in a statement. “Activist judges and anti-choice Republicans cannot be allowed to control Iowans’ lives.”

Since the U.S. Supreme Court ended the national right to abortion in 2022, state legislatures and courts have become central battlegrounds on the issue. Many conservative states, largely in the South and Midwest, have moved to ban or sharply limit the procedure, while other states have passed new abortion protections.

In Iowa, Republican lawmakers, who dominate the State Legislature, tried twice to enact a six-week ban. The State Supreme Court, which is made up of Republican appointees, deadlocked last year on whether the first law, passed in 2018, should be enforced, leaving a lower court’s injunction in place.

Ms. Reynolds responded by calling a special session, in which Republicans swiftly passed another six-week ban over the objections of Democrats and abortion-rights supporters. A state district court had blocked enforcement while the new law was being challenged, which meant that women in the state could continue to seek abortions up until about 22 weeks of pregnancy.

Abortion remains legal in some states bordering Iowa, including Illinois and Minnesota. Other nearby states, including Missouri and South Dakota, have banned the procedure in almost all circumstances.

The 2023 Iowa law that became the focus of a legal challenge allowed for abortions until the point where there was what the legislation called “detectable fetal heartbeat,” a term that medical groups dispute. The law assumed that this was roughly six weeks of pregnancy, before many women know they are pregnant.

The legislation included exceptions after that point for rape or incest, when the woman’s life was in serious danger or she faced a risk of certain permanent injuries, or when fetal abnormalities “incompatible with life” were present.

A Des Moines Register-Mediacom Iowa poll from last year found that 61 percent of adults in the state believed abortion should be legal in most or all cases, while 35 percent believed it should be illegal in most or all cases.

But as Democrats nationally have run on abortion rights in recent elections, retaking state legislative chambers and holding governorships, the party has floundered in Iowa, which not so long ago was a presidential battleground state. In 2022, Governor Reynolds overwhelmingly won re-election, Republicans swept the state’s congressional seats and voters unseated the attorney general and treasurer, both Democrats who had held office for decades.

President Biden has sought to make abortion a central campaign issue again this year, but Iowa is unlikely to be competitive in November. Former President Donald J. Trump carried the state by significant margins in 2016 and 2020.

The Iowa Supreme Court’s ruling focused largely on a question of which standard of review to apply to the new restrictions. The plaintiffs wanted the law tested based on whether it posed an “undue burden” on women seeking abortions, while lawyers for the state said they only had to prove that lawmakers had a “rational basis” in enacting the restrictions.

The four-justice majority agreed with the state’s lawyers and said legislators acted properly under the U.S. Supreme Court standards established in Dobbs v. Jackson Women’s Health Organization, which ended the national right to abortion.

“Every ground the state identifies is a legitimate interest for the legislature to pursue, and the restrictions on abortion in the fetal heartbeat statute are rationally related to advancing them,” Justice Matthew McDermott, who was appointed by Ms. Reynolds, wrote in the majority opinion.

In a dissent, Chief Justice Susan Christensen, also a Reynolds appointee, said the “court’s majority strips Iowa women of their bodily autonomy by holding that there is no fundamental right to terminate a pregnancy under our state constitution.”

“I cannot stand by this decision,” the chief justice wrote. “The majority’s rigid approach relies heavily on the male-dominated history and traditions of the 1800s, all the while ignoring how far women’s rights have come since the Civil War era.”