Social Stressors, Inflammation and Preterm Birth in African-American Women

Purpose: In 2012 in the United States, 11.5% of infants were born prematurely (<37 weeks) and African American women had almost twice the rates of preterm birth compared with non-Hispanic white women. Preterm birth is associated with neonatal mortality and morbidity, childhood illness, and school failures; and it costs $26 billion annually. Attempts to explain preterm birth disparity have focused on social stressors of neighborhood environment and racial discrimination. These social stressors increase psychological stress and are related to preterm birth. Psychological stress and its associated inflammation [e.g., interleukin (IL)-6] are also associated with preterm birth. In contrast, personal resources (e.g., coping, social support) ameliorate stress and have protective effects on preterm birth. Guided by the Stress and Coping model and the Psychoneuroimmunology framework, we examined the relationships among neighborhood environment, racial discrimination, psychological stress, personal resources, inflammation and preterm birth.

Methods: Using a longitudinal descriptive correlational design, we enrolled 114 pregnant African American women. Women completed questionnaires and had blood draw at 16-22 weeks and 26-32 weeks.Birth data were collected from medical records.  

Results:  Women who reported higher levels of perceived neighborhood stressors and more experiences of racial discrimination also reported higher levels of psychological stress and lower levels of personal resources. Psychological stress was related to higher levels of inflammation (IL-6, IL-8). Compared with women with full term birth, women with preterm birth had higher levels of psychological stress as early as 19 weeks gestation. Finally, psychological stress mediated the effects of neighborhood stressors on preterm birth. 

 Conclusion: These results suggest that (1) social stressors are related to psychological stress and inflammation; (2) psychological stress is related to inflammation; and (3) women with preterm birth have higher levels of psychological stress. Knowledge of the social context of African American women’s lives can generate new perspectives for future research, new interventions to reduce racial disparities in preterm birth, improve child outcomes and ultimately reduce the emotional burdens to families.