Purpose-This study examines nonpregnant women's beliefs about whether or not they can influence their future birth outcomes with respect to the baby's health and factors associated with internal locus of control for birth outcomes. Perceived internal control of birth outcomes could be a predisposing factor for use of preconception care, which is recommended for all women of childbearing age by the Centers for Disease Control and Prevention. The overall hypothesis is that internal control of birth outcomes is a function of prior pregnancy experiences, current health status and stress levels, access to health care, and sociodemographics.Methods-Data are from the Central Pennsylvania Women's Health Study random digit dial telephone survey of 2,002 women ages 18−45; the analytic sample is 614 nonpregnant women with current reproductive capacity who reported that they are considering a future pregnancy. Internal control of birth outcomes is measured using 1) a 4-item Internal Control of Birth Outcomes Scale, 2) a single-item measure of Preconceptional Control, and 3) a score reflecting high internal control on both of these measures.Findings-In multiple logistic regression analyses, internal control of birth outcomes is positively associated with older age (35−45 vs. 18−34 years), higher education (some college or more), marital status (currently married or living with a partner), and higher self-rated physical health status on the SF-12v2 (but not mental health status or psychosocial stress). Previous adverse pregnancy outcomes and current access to health care have no association with internal control for birth outcomes.Conclusion-Variables associated with internal control of birth outcomes among women contemplating a future pregnancy are primarily sociodemographic and physical health related. Educational and social marketing efforts to increase women's use of preconception care may be particularly important for women who are likely to have lower internal control, including younger, less educated, unmarried, and less healthy women.Prevention of adverse pregnancy outcomes-including preterm birth, low birthweight, infant mortality, birth defects, and maternal morbidity and mortality-is an important public health goal that has recently received renewed attention owing to the release of the Centers for Disease Control and Prevention's (CDC) "Recommendations to Improve Preconception Health and Copyright © 2008 Health Care-United States" (CDC, 2006). These recommendations focus on improving pregnancy-related outcomes for infants and women by promoting women's health and health care before the first pregnancy and between pregnancies, which is a distinct departure from the traditional focus on the period during pregnancy. This shift reflects growing recognition that the prenatal period is too narrow a window in which to intervene to address many of the maternal health problems and risk factors that could impact negatively on both the mother's and the baby's outcomes (Misra, Guyer, & Allston, 2003). For example, p...