Maternal Stress and Preterm Birth

Abstract

Although there are biological pathways that conceivably might link stress with preterm birth, studies attempting to demonstrate such a relationship have given conflicting results. For the most part, social support has notbeen found to reduce preterm births. The present study is a prospective examination of how such factors as life events, social support, depression, and anxiety related to pregnancy may be associated with birth before 37 weeks' gestation. The study cohort included 1962 women who gave birth in central North Carolina in the years 1996-2000. Participants, aged 16 years and older, were entered into the study at 24-29 weeks' gestation. Many subjects were African-American women, and about half were nulliparous. More than half were not married when entering the study. Low-income households were liberally represented in the study group. The incidence of preterm birth was 12%. Life events, social support, and depression were not associated with preterm birth in this study, but women having medium and high scores for self-rated pregnancy-related anxiety were at increased risk; risk ratios were 1.5 and 2.1, respectively. High scores on a scale of perceived racial discrimination also correlated with an increased risk of preterm birth (risk ratio, 1.4). Similar findings were obtained when alcohol or tobacco use was taken into account. Women with greater self-rated anxiety were more at risk of spontaneous than of medically indicated preterm birth. A risk ratio of 1.8 was associated with life events perceived as having had a negative impact. Among women with negative life events, pregnancy-related anxiety was associated with preterm birth triggered by either labor or ruptured membranes. The association between high levels of pregnancy-related anxiety and preterm birth was less marked when limited to women lacking comorbid medical conditions, but it persisted. These findings suggest that some psychosocial measures are in fact associated with preterm birth.