Though teen birth rates have dropped in the past several decades, more than 750,000 girls between the ages of 15 and 19 still get pregnant in the United States each year. But what would happen if young women were simply given free birth control and educated about the best contraceptive options available to them? Researchers with the Washington University School of Medicine set out to tackle that question, and the answer, they found is clear: When teenagers have access to free, long-acting contraception, pregnancies, births and abortions plunge well below current national averages. The study, published in The New England Journal of Medicine on Wednesday, took place over a five-year period and included more than 1,400 girls, ages 15 to 19, from the St.