The difference has been known for decades, as well as the reason for the difference: Birth control is less expensive and easier for teens to get in many other developed countries than in the United States. And teachers, parents and physicians tend to be more accepting of teenage sexuality and more likely to encourage use of contraception
Studies indicate that about 80 percent of sexually active teen girls in Sweden and about 88 percent in England and France use contraception. In the United States, it's about 61 percent.
So, our customs, religious beliefs, educational practices all lead to a high teen pregnancy rate. We restrict access to birth control and abortion....and now, we seem to be returning to the pre-1970-s when it comes to providing adequate education for pregnant teen and teen mothers.
California, for instance, slashed a successful program for such students in 2008, ruling it was no longer mandatory, and allowed school districts to use the money for other programs.