Although much research has focused on whether the physical demands of employment during pregnancy affect birth outcomes, this article argues that psychological demands should also be considered. Research published since 1980 is reviewed to examine how physical and psychological demands of employment are related to birth outcomes. Evidence for the effect of specific types of physical activities (e.g., lifting, standing) is equivocal, in part due to methodological limitations. However, studies combining several types of physical activities tend to find an association with more adverse birth outcomes. Too few pregnancy outcome studies have examined psychological demands in the workplace to make conclusions about birth outcomes, but the theoretical basis for further research is discussed. This article also argues that physical and psychological demands occur outside of the workplace and must therefore be considered with respect to responsibilities all women face throughout the day. An integrative model for studying these relationships is proposed.