Background and methodology The US Army represents a community of young adults at risk for unintended pregnancy/paternity. Our study evaluated the effect of pregnancy/paternity intention on contraceptive choice amongst new, sexually active and non-pregnant recruits. A total of 592 males and 503 females completed self-administered surveys asking about pregnancy/paternity intention, contraceptive use at last intercourse, and potential confounding factors. A multidimensional measurement of pregnancy intention was developed. Contraceptive efficacy was categorised as a four-level ordinal variable. Multivariate ordinal regression measured the association between pregnancy/paternity intention and the most efficacious birth control method used at last intercourse.

Results Only 7% of participants planned a pregnancy in the next 6 months, but almost 33% of them used no birth control at last intercourse. Each unit increase in pregnancy avoidance scale was associated with a 14% increase in efficacy of birth control method used (p<0.0001). Effectiveness of birth control method increased for age (p = 0.0873), post-secondary education (p = 0.0142) and male gender (p = 0.0019.). Binge drinking reduced the likelihood of being in a higher category of birth control use (p = 0.0258).

Discussion and conclusions Intention to avoid pregnancy and being male was associated with use of higher-level birth control methods.