Ambulatory assessments of psychological and peripheral stress-markers predict birth outcomes in teen pregnancy.

OBJECTIVE: Pregnant adolescents have high rates of poor birth outcomes, but the causes are unclear. We present a prospective, longitudinal study of pregnant adolescents assessing associations between maternal psychobiological stress indices and offspring gestational age at birth and birthweight.
METHOD: Healthy nulliparous pregnant adolescents were recruited (n=205) and followed during pregnancy. Ambulatory assessments over 24h of perceived psychological stress (collected every 30 min) and salivary cortisol (6 samples) and a summary questionnaire, the Perceived Stress Scale, were collected at three time points (13-16, 24-27, and 34-37 gestational weeks). Corticotropin-releasing hormone, C-reactive protein, and interleukin 6 were assayed from blood taken at the latter 2 sessions. A final sample of 119 participants was selected for analyses.
RESULTS: The ambulatory assessment of perceived psychological stress was positively correlated with the Perceived Stress Scale (r=.20, p=.03) but neither was associated with any of the biological assays (all ps>.20). Based on backward selection regression models that included all stress variables and relevant covariates, the ambulatory assessments of perceived psychological stress and cortisol - though not the Perceived Stress Scale - were negatively associated with gestational age at birth (F(4, 107)=3.38, p=.01) while cortisol was negatively related to birthweight (F(5, 107)=14.83, p<.0001).
CONCLUSIONS: Targeted interventions to reduce psychological and biological indicators of heightened stress during pregnancy may have positive public health benefits for the offspring given the associations of shortened gestation and lower birthweight with risk for poor mental and physical health outcomes.