Similar restrictions that have been enacted in other states have been tied up in legal challenges. Bans on abortions after 20 weeks have been adopted by 11 other states, but in three of those states — Arizona, Georgia and Idaho — courts have blocked the laws from taking effect. The requirement that doctors have admitting privileges at a nearby hospital has been blocked by courts in Mississippi, Alabama and North Dakota.

The United States Supreme Court has ruled that states can regulate abortions so long as the rules do not pose an “undue burden” on a woman’s right to an abortion. Opponents of the law are likely to argue that the surgical-center standards and their effect on women seeking abortions across the state pose an undue burden and are thus unconstitutional.

“The A.C.L.U. is involved in litigation in 5 of the 10 states where similar abortion restrictions have been enacted, and we are evaluating our options in Texas,” said Terri Burke, the executive director of the American Civil Liberties Union of Texas. “What makes Texas different is our size: House Bill 2 leaves 35 percent of the population without access to abortion care and those are rural and, often, poor women.”

The provision banning abortions at 20 weeks after fertilization and later is based on a medically disputed theory that a fetus can feel pain at that stage. The Supreme Court has ruled that women have a right to an abortion until the point at which the fetus is viable outside the womb — usually around 24 weeks after a woman’s last menstrual period, or 22 weeks after fertilization.

Mr. Perry addressed the issue of fetal pain at the bill-signing ceremony on Thursday. “At five months, many studies indicate that these children feel pain,” he said, adding that it was Texans’ responsibility “to give voice to the unborn individuals whose survival is at stake.”

The ceremony was a procedural coda to the heated battle over abortion that has played out at the Capitol. Thousands of men and women — on the both sides of the debate, though opponents of the bill largely outnumbered supporters — have testified, rallied and protested there since June, when Mr. Perry added the bill to the Legislature’s agenda.

The bill failed to pass during the regular session, which ended May 27, so Mr. Perry added it on June 11 to a special session in an effort to get it passed. But at the end of the special session on June 25, an 11-hour filibuster by State Senator Wendy Davis, Democrat of Fort Worth, helped kill the bill, turning her into a national political celebrity.

Mr. Perry responded by calling a second special session, and the Republican-dominated Legislature quickly passed the restrictions last week. Though their efforts to block the bill had ultimately failed, Democrats have been emboldened by the filibuster and the battle over abortion. In June, Ms. Davis received nearly $1 million in campaign contributions in two weeks. She received more than 15,000 individual contributions, many from people who gave her $50 or less.