LAUSR

BACKGROUND Little is known about the maternal cortisol awakening response (CAR) in the first pregnancy trimester. Similarly unknown is how the CAR in early gestation relates to other steroid hormones, such as estriol. Maternal estriol in blood and urine is used to monitor fetal well-being since it is produced by the fetoplacental unit from fetal precursors. Low levels have been associated with maternal-fetal complications. We were recently able to show that estriol is measurable in maternal saliva from 6 weeks' gestation onwards. However, its pattern following morning awakening and potential links with salivary cortisol in early gestation is relatively unknown. In this prospective study, we explored the cortisol and estriol responses to morning awakening in first-trimester pregnant women, the potential association of these endocrine variables with maternal stress and resilience factors, and their predictive value for the further pregnancy course. METHODS Fifty-one women with an uncomplicated, singleton pregnancy responded to questionnaires measuring chronic and pregnancy-specific stress, emotional support, and daily uplifts at 6 weeks' gestation. At 8 and 10 weeks, the women collected saliva samples immediately, 30, and 60 min after morning awakening. After 12 weeks, 40 women reported on the further pregnancy course, of whom 6 had developed complications. RESULTS In response to morning awakening, cortisol levels increased significantly at 10 weeks (p = .04), while estriol levels decreased significantly at both 8 and 10 weeks (p < .001). A stronger cortisol increase was linked to a stronger estriol decrease at 8 (p = .03), but not at 10 weeks. Then, perceived emotional support at 6 weeks was negatively associated with cortisol baseline at 8 (p = .01) and positively with estriol baseline at 10 weeks (p = .03). Moreover, higher pregnancy-specific stress was related to a lower estriol baseline at 8 weeks (p = .047). Furthermore, compared to healthy women, those with complications at follow-up had already reported less emotional support (p = .03) and fewer daily uplifts (p = .03) at 6 weeks. These women also seemed to lack a significant estriol response to morning awakening at 8 weeks (p > .10). DISCUSSION These findings advance our knowledge of cortisol and estriol secretion following morning awakening and encourage the investigation of E3 in addition to cortisol when researching prenatal stress and its consequences for maternal and fetal health.