Birth-Intention Time Horizon as a Predictor of Contraceptive Method Effectiveness

Both contraceptive method research and contraceptive program designs have given more attention to if a woman currently wants to have a child than to when she wants a child. We examine how predictive is a woman's intended duration to a (next) birth for her type of contraceptive method currently used, ranked by the method's effectiveness. We hypothesize that a longer intended duration will be associated with choosing a more effective method.

We pooled observations of women (n = 7,324 in total) across the two population-representative surveys in Delaware and Maryland: the Behavioral Risk Factor Surveillance System and the Survey of Women. We classified birth-timing intentions into wanting a child in less than 2 years, wanting a child but being uncertain when, wanting a child in 2 or more years, and not wanting (additional) children. Contraceptive method was classified as highly effective (intrauterine devices and implants), moderately effective (e.g., contraceptive pills), less effective (e.g., condoms), and no method. We used multinomial logistic regression to estimate relative risk ratios and predicted probabilities of using each method type, and no method, adjusting for sociodemographic characteristics.

As a woman's birth-timing intention horizon lengthens, her probability of using a highly effective method increases, and her probability of using no method decreases. Being uncertain about birth timing is associated with a substantially lower probability of using any type of contraceptive method relative to having clear intentions.

Our findings underscore the importance for contraceptive counseling and contraceptive access program design of considering birth-timing intentions beyond the year immediately ahead.