Background:
Annually, one out of every two women in the US are at risk for an unintended pregnancy. Little is known, however, about the differences between women at higher and lower risk for an unintended pregnancy.

Objectives:
Our goal was to determine whether risk factors were more pronounced among women at higher risk for an unintended pregnancy than women at a lower risk.

Methods:
Using the Behavioral Risk Factor Surveillance System (2002, 2004 datasets), we examined health factors of non-pregnant, 18-44 year old, fertile women. Unintended pregnancy risk sorted women into one of two categories: high-risk (HR) (n=16,113) and low-risk (LR) (n= 39,426). Logistic regression was used to estimate adjusted prevalence odds ratios (aPOR) and 95% confidence intervals (CI) for lifestyle factors.

Results:
The two groups reported similar health insurance and income proportions but differed on several other demographic characteristics. A larger proportion of women in HR group were Black (14.4% CI 13.4, 15.4 vs 11.9% CI 11.4, 12.5), of advanced maternal age (51.1% CI 49.7, 52.5 vs 28.8% CI 28.1, 29.6), married (59.0% CI 57.6, 60.4 vs 53.1% CI 52.2, 54.0), while a smaller proportion attained a college degree (25.5% CI 24.4, 26.7 vs 35.7% CI 34.9, 36.5). Using the LR groups as a reference when calculating adjusted prevalence odds ratios (aPOR), HR women were less likely to drink any alcohol (aPOR .71, CI .65, .76), binge drink (aPOR .87 CI .78, .97), or heavy drink (aPOR .85 CI .75, .99). However, they were also at a higher odds for being a current smoker (aPOR 1.2 CI 1.1, 1.3), lower odds to exercise (aPOR .73 CI .67, .80), and lower odds for taking folic acid supplements (aPOR .58 CI .35, .96).

Conclusion and implications for practice:
These findings support the hypothesis that demographic characteristics differ between women at high and low risk for an unintended pregnancy, with HR women less likely to less likely to take folic acid, less likely to exercise, and more likely to smoke.Public health messaging needs to be improved especially among those women at the highest risk for an unintended pregnancy, if we expect success in reaching the national preconceptional health recommendations.