Associations between Early Life Stress, Prenatal Stress, Hair Cortisol and Birth Outcomes

Abstract

Environmental influences before and during pregnancy can significantly impact offspring development. The aim of this study is to research the relationship between maternal early life stress (ELS), prenatal psychosocial stress, prenatal hair cortisol (HCC) and birth outcomes in a population of Argentinian women. We address open questions in the literature including whether there is an interaction between ELS and prenatal stress that is related to HCC or birth outcomes, and whether changes in HCC over pregnancy are associated with ELS, prenatal stress, and birth outcomes. Upon delivery, we collected data on ELS, prenatal life events, HCC (sample divided into first half and second half of pregnancy) and birth outcomes in a population of middle class Argentinian women (N = 69). We used Bayesian Networks with robust hierarchical linear models to estimate effects according to our research aims. We found no strong evidence for a relationship between ELS and HCC or the birth outcomes. Neither did our data indicate a strong relationship between prenatal stress and HCC or the birth outcomes, also not in interaction with ELS. However, our data indicated that age was positively associated to HCC increases, while education was negatively associated to HCC increases. Larger HCC increases were negatively related to birth weight after accounting for gestational age. Change in cortisol over time during pregnancy might be related to birth outcomes. Future research should confirm these results and strive to identify which factors contribute to change in cortisol over time during pregnancy.