What happens if you stop taking birth control and then start taking it again?

Women who start taking birth control and then stop are more at risk for pregnancy due to the inconsistent nature of how hormones in the pill are administered, according to the Center for Young Women's Health. The pill, when taken once a day, is 99 percent effective in preventing pregnancy.

If a woman stops taking the pill for a reason other than the typical break for her period, she breaks the cycle of how hormones are administered to her body, and the pill becomes only 92 percent effective. If a woman stops taking the pill, she should use a condom as a back-up birth control method to prevent pregnancy, notes the Center for Young Women's Health.