Comparison of hair cortisol levels in mothers who deliver at preterm and term

Abstract

Approximately 1 in 10 babies in the U.S. is born premature or preterm. Inadequate understanding of the psychoneuroendocrine immune mechanisms that facilitate length of gestation and initiate parturition contributes to our inability to intervene effectively to prevent preterm labor. Hair cortisol serves as a practical measure of long-term retrospective cortisol activity. This study used descriptive, correlation, and between-group comparison analysis. We compared hair cortisol and perceived stress scores (PSS) in mothers who delivered preterm (n = 22) and mothers who delivered term (n = 30). The mean gestational age at the time of preterm delivery was 31.45(4.2) weeks and at the time of term delivery was 39.45(1.1) weeks. Cortisol was significantly different between term and preterm in the third trimester (t = 2.16, df = 48, p = 0.04) and trending towards significance in the second trimester (dt = 1.88, df = 48, p = 0.06). PSS were significantly different between term and preterm (t = −2.96, df = 50, p = 0.05). Our data did not provide any support that the rate of change in cortisol levels was greater in the preterm delivery group. There appears to be a blunted, flattened pattern of cortisol levels across the gestation in the women who delivered preterm and diminished HPA responsiveness in mechanisms that promote preterm labor. Future studies are needed to further evaluate best strategies for measuring the mechanisms of allostatic load during pregnancy, along with psychoneuroendocrine and immune triggers and placental responses that lead to premature birth.