As several US states have implemented some of the most restrictive abortion laws in the nation, a study published in the journal Obstetrics & Gynecology suggests that legislatively limiting access to the procedure results in a delay that increases the number of second-trimester abortions.

Researchers compared changes in second-trimester abortions before and after a 2013 Texas law banning abortion after 20 weeks. The move resulted in the closure of half of the state’s abortion facilities, provider shortages, and delayed access to abortion care. Although the total number of abortions declined by 18 percent, the number of women seeking abortions in the second trimester increased by 13 percent due to lack of access, including an average wait of three days or longer for the initial state-mandated consultation visit required at least 24 hours before the procedure is performed.

"The 2013 law created even more barriers to abortion in Texas, and we can clearly see the result – women seeking services were pushed into the second trimester," said the study’s lead author Kari White in a statement. "Women's health policies should focus on ensuring women have access to timely, evidence-based care, not on creating obstacles that delay it."

Just around 10 percent of all US abortions occur in the second trimester and, although those performed after 12 weeks are generally safe, the risk goes up as the pregnancy progresses, making timely access crucial for health and safety. Furthermore, abortions after the first trimester are often more costly and time-intensive partially due to the fact that fewer facilities offer the service.

Earlier this month, the State of Alabama passed the strictest abortion law in the US, banning all cases of abortion in the state, even in cases of rape and incest. The only exemption would be if the pregnancy poses a physical danger to the health of the mother. The American Civil Liberties Union filed a suit Friday challenging the ban, saying it runs directly counter to America’s landmark precedent-setting Roe v. Wade decision. Other southern states have joined Alabama, most recently with Missouri’s governor signing a bill banning abortion after eight weeks.

"Given the recent national debate over later abortions, it's important to recognize that restrictive laws are a major obstacle preventing women from obtaining abortions earlier in pregnancy," said researcher Daniel Grossman. "Once a patient has decided to have an abortion, access to care should be expedited, rather than placing barriers in her way that unnecessarily delay her care. Those who support reducing the number of later abortions should also support eliminating these unnecessary and burdensome restrictions."

Legal requirements vary from state to state in terms of where, how, and at what point during a pregnancy an abortion may be performed but many argue abortion is not the antidote to unplanned pregnancies. Research shows that a key driver in reducing abortion rates is improved contraceptive use, awareness, and accessibility. Between 2008 and 2011, a study published in the New England Journal of Medicine noted that the US unintended pregnancy rate declined by 18 percent for women and girls aged 15-44 – its lowest in three decades – largely due to improved contraceptive use during the same period.