Psychological and physiological stress: Impact on preterm birth

Stress increases corticotropin-releasing hor-mone and may ultimately result in increased uterine contractility. Stress also increases cytokine production, which independently may lead to preterm birth or increase susceptibility to infection, thereby increasing the risk of preterm birth. Finally, stress may change health behaviors that lead to preterm birth. Research findings on the relationship between stress and preterm birth have been contradictory. In this article, the authors propose a model of the relationship between stress and preterm birth, evaluate the research on stress and pregnancy outcomes, and dis-cuss the implications for nursing practice an