To investigate the influence of sexual activity and contraceptive use on the decline in adolescent birth rates and pregnancy rates since 2007.

We estimated trends in pregnancy risk from 2007 to 2014 using national data on behaviors of women aged 15–19.

In 2007–2014, increases occurred in use of one or more contraceptive methods at last sex (78%–88%), dual method use (24%–33%), long-acting reversible contraception including intrauterine device and implant (1%–7%), withdrawal (15%–26%), and withdrawal in combination with other methods (7%–17%). Pill use rose and then fell over time. Level of sexual activity did not change over time. The decline in pregnancy risk among women aged 15–19 was entirely attributable to improvements in contraceptive use.

Improvements in contraceptive use—including increases in use of long-acting reversible contraception and withdrawal in combination with another method—appear to be driving recent declines in adolescent birth and pregnancy rates.