A new study published this week in the journal Obstetrics & Gynecology shows that providing free birth control to women could reduce abortion rates by 62% to 78%. In addition, access to no-cost birth control “substantially reduced” unplanned pregnancies.

The study, conducted by researchers at the Washington University School of Medicine, looked at 9,256 women, ages 14 to 45 in the St. Louis area between 2007 and 2011. The women were given a choice of birth control methods, ranging from long-term IUDs to the classic birth control pill. Around 75% of women in the study chose IUD or implant methods of birth control, which have lower failure rates than pills but have higher up-front costs.

From 2008 to 2010, the women in the study had annual abortion rates ranging from 4.4 to 7.5 per 1,000 women. This is significantly lower than the U.S. national abortion rate, which is 19.6 per 1,000 women.

The study also found that for girls age 15 to 19 who had access to free birth control, their annual birth rate was 6.3 per 1,000 women, far below the U.S. national average of 34.3 per 1,000 women.

“This study shows that by removing barriers to highly-effective contraceptive methods such as IUDs and implants, we can reduce unintended pregnancies and the need for abortions,” said lead author Dr. Jeff Peipert, lead author of the study and professor of Obstetrics and Gynecology at Washington University. “Unintended pregnancy remains a major health problem in the United States, with higher proportions among teenagers and women with less education and lower economic status. The results of this study demonstrate that we can reduce the rate of unintended pregnancy, and this is key to reducing abortions in this country.”

This study comes just months after a provision in the Patient Protection and Affordable Care Act (also known as ‘Obamacare’) mandated that all health insurance plans cover contraceptives for women, without requiring a co-pay.

Washingtion University prepared a video on the project, which illustrates the more interesting facts from the study: