The study suggests that misoprostol alone safely terminates pregnancy after 10 weeks

As more than a dozen states outlawed abortions in the past year, women experiencing unwanted pregnancies in increasing numbers have turned to self-administered medical abortions.

But the tedious and time-consuming methods required to procure the drugs create delays, and often mean that the pregnancy is more advanced by the time the drugs arrive. The new study, one of the first on medical abortions done after the first trimester of pregnancy, offers these women some reassurance, researchers said.

said Dr. Daniel Grossman, professor of obstetrics, gynecology, and reproductive sciences at the University of California, San Francisco. “As in-clinic abortion care becomes less available in many parts of the country due to statewide bans, self-managed abortions will become more common, as we are already seeing.”

The research also suggests an alternative route to medical abortion if access to mifepristone is severely restricted. In April, the Supreme Court blocked a lower court ruling that would have halted the distribution and sale of mifepristone across the United States while the case makes its way through the legal system.

About 44 percent of the participants in the new study used only misoprostol, which is prescribed for many conditions and is available in many countries without a prescription.

About 90 percent of the women in the study successfully terminated their pregnancies with self-managed medical abortions, without the need for any additional intervention. Five percent have a procedure to complete an abortion, and 5 percent have an incomplete abortion.

A two-drug regimen of mifepristone and misoprostol has been approved by the Food and Drug Administration for use during only 10 weeks of pregnancy, under the supervision of a healthcare provider.

But the World Health Organization, bearing in mind the shortage of healthcare providers in most parts of the developing world, supports self-managed medical abortions in pregnancies up to 12 weeks without medical supervision.

The new report was a sub-analysis of a larger study of 1,352 women who had self-induced abortions at different stages of their pregnancies, and the number with the most advanced pregnancies was relatively small.

Only three participants had self-abortions with pregnancies of 17 weeks and longer, and the study authors called for more research into medical abortion and subsequent pregnancies.

Access to the medications used in these abortions, which are often ordered through the mail, continues to be a flashpoint in the abortion debate in the United States.