Providing no- or low-cost birth control pills over the counter may reduce costs and prevent up to a quarter of unplanned pregnancies, researchers say.

Many women would likely start using oral contraceptives if they were available with little or no up-front cost over the counter instead of with a prescription, they suggest in the journal Contraception.

“Making pills available without a prescription would remove the need for unnecessary, time-consuming and sometimes expensive visits to doctors’ offices and clinics,” wrote Diana Foster, the study’s lead author from the University of California, San Francisco, in an email to Reuters Health.

It would also allow women to avoid often monthly waits in line at the pharmacy, she said.

The Centers for Disease Control and Prevention says about half of U.S. pregnancies are unplanned. Most occur among younger, poorer women. The primary cause is lack of access to contraception.

The researchers used computer models to analyze several studies and databases to predict how unintended pregnancy rates might change if birth control pills were available without a prescription and with little or no cost.

Currently, 30 percent of low-income women ages 15 to 44 years use birth control pills. Other contraception methods are less common, and 18 percent of these women use no contraception.

Prescription birth control pills cost the public sector nearly $400 per woman each year. A pregnancy costs the public sector almost $3,000 from conception to the child’s second birthday, according to a 2010 study.

The authors of the new study project that 21 percent of low-income women at risk for unplanned pregnancies are very likely to use over-the-counter birth control pills, if available.

“We estimate that up to a third of women using withdrawal as their main method and one in six women using no method would use pills if they were available without a prescription,” Foster said.

The ultimate number depends largely on cost, they say.

If there is no out-of-pocket cost, the number of women taking the pill could increase by up to 21 percent and the number a less effective contraceptive method or no method at all could decrease by more than 30 percent, preventing one in four unplanned pregnancies.

Overall, the analysis projects that making free or low-cost birth control pills available over the counter could save public insurance programs up to 10 percent and prevent up to a quarter of unplanned pregnancies.

“The cost of pregnancy-related medical care far outweighs the cost of preventing an unintended pregnancy,” Foster said.

Under the 2010 Affordable Care Act, “most insured women do have access to at least some oral contraceptive pills with no co-pay,” she said, adding that there are some exceptions.

“The pill has been around so much longer than the other birth control methods that it would be unlikely for the other methods to go over the counter until there is some experience with OTC pills first,” said senior author Dr. Daniel Grossman of Ibis Reproductive Health in Oakland, California.

With political support building among Republicans and Democrats it may finally be the right time to actually make the Pill available over the counter, Foster said.