Many women do not know they are pregnant before six weeks, and, according to a joint statement about the lawsuit from groups that support abortion rights, about 85 percent of women who obtain abortions in Texas do so after about six weeks of pregnancy.

“What happens in Texas when it comes to anti-abortion strategy and anti-abortion regulation unfortunately doesn’t stay in Texas,” said Amy Hagstrom Miller, the president and chief executive of Whole Woman’s Health and Whole Woman’s Health Alliance. Whole Women’s Health operates four clinics in the state.

Some of the most significant abortion laws in the country started in Texas, she said, including Roe v. Wade, the 1973 ruling that established federal protection for abortion, and the Whole Woman’s Health decision in 2016, when the Supreme Court struck down part of a Texas law that could have drastically reduced the number of abortion clinics in the state.

“Texas is grounds both for anti-abortion restrictions and also for some of the biggest wins against those restrictions that we’ve seen in the country,” Ms. Hagstrom Miller said.

The law comes as abortion rights opponents have intensified their legal strategy in recent years, passing restrictions in state legislatures with the frequent goal of defending them at the Supreme Court. The makeup of the nation’s highest court has recently shifted to give conservatives a solid majority, following the confirmation of three new justices appointed by former President Donald J. Trump.

More abortion restrictions have been signed in a single year in the 2021 legislative season in the United States than in any other year since Roe, according to the Guttmacher Institute, which tracks abortion statistics and supports abortion rights.

John Seago, legislative director for Texas Right to Life, the largest anti-abortion organization in the state and a group involved in the legal strategy behind the law, called the lawsuit “a desperate legal move.”

“There is no reason to believe that this state judge is violating any federal laws or violating the Constitution by simply having jurisdiction over a lawsuit that the State of Texas has authorized,” he said. “Don’t miss the point of this bill: The point of the bill is that abortions are stopped after six weeks.”