Wait times to get an abortion in Texas have grown in some metropolitan areas, a trend that could be felt statewide if the U.S. Supreme Court allows the strictest provision of the state’s 2013 abortion law to take effect. That's according to a new report by the Texas Policy Evaluation Project at the University of Texas at Austin.

About half of Texas abortion clinics have closed their doors following the passage of House Bill 2, elements of which have been tangled up in court since lawmakers approved it.

As a result, in the last year, some women in Dallas, Fort Worth and Austin have waited up to 20 days to obtain the procedure. While wait times have remained stable and short in Houston and San Antonio, the researchers projected that they could also grow in those areas if the Supreme Court upholds additional restrictions in the Texas abortion legislation. 

Under HB 2, doctors who perform abortions are required to have admitting privileges at a hospital within 30 miles of an abortion clinic. A separate provision of the of the law, which is currently blocked from enforcement by the Supreme Court, would require Texas abortion facilities to meet the same standards as so-called ambulatory surgical centers, from minimum sizes for rooms and doorways to pipelines for anesthesia and other infrastructure.

Among the wait-time research findings in the state’s metropolitan areas:

• Dallas has seen the biggest increase in wait times since the researchers' review began in November 2014, particularly after June, when a high-volume clinic in the area closed its doors. Before the closure of that facility, which performed between 350 and 500 abortions a month, the average wait time in Dallas was about five days. After the closure, wait times grew to as long as 20 days.
• In neighboring Fort Worth, wait times grew to as long as 23 days following the closure of that same Dallas clinic. Before the closure, wait times crept up from six to as many as 13 days between December 2014 and February 2015, when a Fort Worth facility temporarily stopped performing abortions. 
• Wait times have fluctuated in Austin, where there are currently two abortion facilities. They spiked to 20 days in December 2014 but have slowly decreased since, recently hitting an average of more than 10 days. Only one of Austin's two clinics meets the standards of an ambulatory surgical center, so researchers project a big increase in wait times in Austin if the Supreme Court rules in the state's favor. 
• In Houston, wait times have averaged less than five days since November 2014. In March 2015, some patients waited up to 13 days for an appointment, but the wait times have since dropped. Like Austin, researchers predicted wait times could increase depending on the high court's ruling; only two of the city's six facilities meet ambulatory surgical center standards.
• Wait times have also averaged less than five days in San Antonio, where three ambulatory surgical centers are providing abortion care. The longest wait time occurred in January 2015, at nine days. 

“The long wait time at some of the [abortion clinics that meet ambulatory surgical center standards] suggests that these facilities are not meeting the existing demand for services,” the researchers wrote in the report.

The researchers also projected that growing wait times could lead to a significant increase in the number of abortions performed in the second trimester.

Even without lengthy wait times, women seeking abortions in Texas are already up against the clock. HB 2 also banned abortions after 20 weeks of pregnancy. 

The UT research findings come as abortion providers wait for the Supreme Court to decide whether it will take up a legal challenge to the Texas abortion law; a decision is expected within weeks.

Attorneys for a coalition of abortion providers who sued the state in 2014 have argued that the Texas restrictions are unconstitutional because they create an undue burden on women in far corners of the state, who could be left to travel more than 150 miles for the procedure in the event the ambulatory surgical center rule took effect. 

The Texas attorney general's office has argued that the abortion restrictions are constitutional, reasonable measures meant to improve women's health. Attorneys for the state have also said the regulations would not create an undue burden for a majority of women seeking the procedure.

The U.S. 5th Circuit Court of Appeals has previously upheld both the ambulatory surgical center and admitting privileges provisions in Texas' law, granting an exemption for a McAllen clinic. The U.S. Supreme Court in June sided with Texas abortion providers and temporarily blocked the 5th Circuit’s ruling, in particular prohibiting the state from enforcing the ambulatory surgical center provision statewide.

If the Supreme Court declines to take up the Texas case, the lower court’s ruling would stand. 

Disclosure: The University of Texas at Austin is a corporate sponsor of The Texas Tribune. A complete list of Tribune donors and sponsors can be viewed here.