Free birth control led to dramatically lower rates of abortions and teen births, a large study concludes. The findings were eagerly anticipated and come as a bitterly contested Obama administration policy is poised to offer similar coverage. The project tracked more than 9,000 women in St. Louis, many of them poor or uninsured. They were given their choice of a range of contraceptive methods at no cost — from birth control pills to goof-proof options like the IUD or a matchstick-sized implant. When price wasn't an issue, women flocked to the most effective contraceptives and these women experienced far fewer unintended pregnancies as a result.