AUSTIN, Texas (AP) - About a third of abortion providers in Texas were expected to stop offering the procedure Friday after the 5th Circuit Court of Appeals ruled that Texas may begin enforcing some of the strictest regulations in the country. Here's a look at the law, the legal opinions and national implications: Known as House Bill 2, it includes four restrictions on when, where and how a woman may obtain an abortion. The first provision requires doctors who perform abortions to have admitting privileges at a hospital within 30 miles of the clinic. Another provision bans abortions after 20 weeks unless the health of the woman is in immediate danger. If a woman wants to induce an abortion by taking a pill, the state will require her to take the pills in the presence of a doctor at a certified abortion facility. Lastly, beginning Sept. 1, 2014, all abortions must take place in a facility that meets the infrastructure requirements for an ambulatory surgical center. Twelve abortion providers say they have attempted to obtain hospital privileges for their doctors, but so far none of the hospitals have responded to the requests. That means those clinics can no longer offer abortions, leaving at most 20 facilities open in a state of 26 million people. All of those facilities are in metropolitan areas, with none in the Rio Grande Valley along the border with Mexico. Currently, only six out of 32 abortions clinics in Texas qualify as ambulatory surgical centers, and some have doctors who do not meet the admitting privileges requirement. Texas women undergo an average of 80,000 abortions a year. Earlier this week, federal District Judge Lee Yeakel blocked enforcement of the law, ruling that the admitting-privileges requirement served no medical purpose. Because the measure would close 12 clinics, he also concluded it would deny women their right to an abortion. A three-judge panel considered an emergency request to lift the injunction filed by Texas Attorney General Greg Abbott, who argued that the lower-court judge did not properly follow the legal tests set out in previous U.S. Supreme Court decisions. In her unanimous opinion for the appellate panel, Judge Priscilla Owen wrote that Planned Parenthood failed to show that requiring admitting privileges produced an undue burden, largely because so many abortion doctors have privileges. She also noted that requiring women to drive 150 miles or more to obtain an abortion from a doctor with privileges did not meet the legal test of an undue burden. Utah, Kansas and Tennessee already enforce an admitting-privileges requirement for either the doctor or the abortion clinic's medical director, but temporary injunctions block similar laws in three states. The 5th Circuit's decision in the Texas case differs from its decision not to overturn a temporary injunction against Mississippi's law. A key factor appears to be that enforcement of that law would force the closure of Mississippi's sole remaining abortion clinic. Federal judges in Alabama and Wisconsin have imposed temporary injunctions, and a state judge blocked North Dakota's version of the law.