Stressed-out pregnant women are at risk for delivering early or giving birth to babies with lower-than-desired birth weights. A new study finds that a biomarker typically associated with chronic stress appears to be present when women of childbearing age report having stressful lives. Up to 90 percent of adults are infected with Epstein-Barr virus (EBV), but the virus stays latent for most of them. Adequate immune function is required to maintain EBV in this latent state. However, when an individual experiences chronic stress, immune dysfunction allows the EBV to reactivate and release viral antigen. Elevated EBV antibody titer serves as an indirect measure of chronic stress and has been associated with a wide range of chronic stressors.
To test whether self-reports of stress coincide with stress biomarkers, researchers used blood samples and questionnaires from 205 reproductive-age women who were receiving welfare in the Chicago area. After determining the women's levels of EBV and C-reactive protein (CRP), another common stress biomarker, they compared the results with the women's responses to questions on stress. The questions probed for external stressors, such as life events and hardships; stress enhancers, such as mental health or substance abuse problems; stress buffers, including social and community support; and perceptions of stress, including discrimination, economic troubles, and dangerous neighborhoods.
Ann E. B. Borders, M.D., M.Sc., M.P.H., of Northwestern University, and colleagues found that EBV levels were indeed linked to the women's reports of chronic stress. For instance, women who reported elevated levels of perceived stress or discrimination had higher levels of EBV than women who had lower stress levels or had not experienced discrimination. However, CRP levels were not strongly associated with the women's self-reported stress.
These findings are noteworthy because they connect high stress levels and discrimination with the disparity black women experience with preterm births and low-birth-weight infants, the authors suggest. Because all but one of the women in the study were willing to provide a blood sample for the researchers, this study also demonstrates that community-based research studies such as this one can surmount the trust and follow-up issues that can occur in hospital-based studies. The study was supported in part by the Agency for Healthcare Research and Quality (T32 HS00078).
See "The relationship between self-report and biomarkers of stress in low-income reproductive-age women," by Dr. Borders, William A. Grobman, M.D., M.B.A., Jane L. Holl, M.D., M.P.H., and others in the December 2010 American Journal of Obstetrics & Gynecology 203(6), pp. 577e1-577e8.