The state of Colorado has been conducting a massive experiment with birth control over the last 6 years. Teens and low-income women were offered free IUDs and implants that prevent pregnancy for years. Officials wondered if women would sign up for the family planning assistance if it were free.
Sabrina Tavernese in the New York Times:
They did in a big way, and the results were startling. The birthrate for teenagers across the state plunged by 40 percent from 2009 to 2013, while their rate of abortions fell by 42 percent, according to the Colorado Department of Public Health and Environment. There was a similar decline in births for another group particularly vulnerable to unplanned pregnancies: unmarried women under 25 who have not finished high school.
"Our demographer came into my office with a chart and said, 'Greta, look at this, we've never seen this before,' " said Greta Klingler, the family planning supervisor for the public health department. "The numbers were plummeting."
Colorado's Effort Against Teenage Pregnancies Is a Startling Success [NYT]
Here's the related press release from Colorado: State health department seeks funding for successful family planning initiative. According to that announcement, "the state avoided more than $80 million in Medicaid costs" during the same time period referenced above.