Trends in Ages at Key Reproductive Transitions in the United States, 1951-2010

The large majority of the reproductive years are spent sexually active. Thus, women have a lengthy period during which they require effective methods. In particular, the period between first sex and first childbearing has lengthened, but long-acting method use, although increasing, has not kept up with this shift. Moving the contraceptive method mix toward underutilized but highly effective contraceptive methods has the potential to reduce the unintended pregnancy rate.