Posttraumatic stress disorder, smoking, and cortisol in a community sample of pregnant women

Abstract

Background: The prevalence of posttraumatic stress disorder (PTSD) in the United States is higher among pregnant women than women generally. PTSD is related to adverse birth outcomes via physiological and behavioral alterations, such as smoking.

Methods: We utilize salivary cortisol measures to examine how traumatic stress, smoking and the hypothalamic-pituitary-adrenal axis interact. Pregnant women (n=395) gave cortisol specimens as part of a cohort study of PTSD and pregnancy at three health systems in the Midwestern United States. Women were divided into three groups: nonsmokers, quitters (who stopped smoking during pregnancy), and pregnancy smokers. Mean cortisol values at three points, sociodemographics, trauma history, and PTSD were compared across groups. We assessed the association of smoking group and PTSD with late afternoon cortisol levels.

Results: Smokers, quitters, and nonsmokers differed on demographic risk factors and PTSD symptom load. Late afternoon and bedtime cortisol measures were significantly positively correlated with smoking in pregnancy, with smokers with PTSD presenting the highest cortisol levels. Regression analysis showed that smoking in pregnancy was associated with higher late afternoon cortisol in an additive manner with PTSD symptoms.

Conclusions: Smoking appears to have a different relationship with cortisol level for those with and without PTSD. This is the first study to show additive effects of smoking and PTSD on cortisol levels in pregnant women. Since high cortisol, smoking, and PTSD have been shown to adversely affect perinatal outcomes, and since those continuing to smoke in pregnancy had the highest PTSD symptom load, PTSD-specific smoking cessation programs in maternity settings are warranted.

Keywords: Cortisol; PTSD; Pregnancy; Tobacco use; Trauma.

Figure 1

ANOVA comparisons of late afternoon cortisol levels across smoking groups with the sample stratified by PTSD diagnostic status. Bar graphs depict natural units (ug/dL) while test uses log-transformed values.