The Relationship between Prenatal Stress, Depression, Cortisol and Preterm Birth: A Review

Preterm birth is one of the most common adverse pregnancy outcomes. Maternal risk factors such as stress and depression have been associated with preterm birth. Preterm infants are at a higher risk of poor growth and neuro developmental outcomes. The objective of this paper is to examine the relationship between maternal stress, depression, cortisol level, and preterm birth. Preterm birth is one of the most common adverse pregnancy outcomes with a global prevalence of 9.6% and one of the major contributors to infant mortality and morbidity. The association between psychosocial stress and preterm birth, although examined for more than 25 years, has not yet been fully established. A systemic review was conducted in which research studies and review articles from 1970 to 2012, published in English, focusing on human subjects, and addressing the relationship between stress, depression, cortisol and preterm birth were included in this review. The studies examining the relationship between stress, cortisol levels and preterm birth have shown inconsistent findings that may be explained by varied study designs, differences in defining and measuring stress, timing of stress measurement, sample characteristics, and study designs. The relationship between stress, cortisol levels and preterm birth may be multifactorial and complex with premature birth being the final common pathway. A longitudinal cohort study, with a large sample size and multiple measures of stress, depression, and cortisol level, as well as a measure of anxiety and other stress hormone biomarkers may add new knowledge and enhance our understanding about the contribution of psychosocial stress to preterm birth.