Browsing by Subject "Ohjelmoitumishypoteesi"

Goals: According to Developmental Origins of Health and Disease hypothesis, maternal prenatal factors are associated with offsprings’ health and susceptibility for non-communicable disease. In previous studies, maternal cortisol and sleep difficulty have been separately associated with multiple negative outcomes for the offspring. However, little is known about the association of maternal sleep difficulty and cortisol during pregnancy. The goal of this thesis is to examine the association of sleep difficulty and maternal diurnal cortisol during early pregnancy. Methods: The study sample (N=310) comes from the prospective pregnancy cohort study “The InTraUterine sampling in early pregnancy” (ITU). Sleep difficulty was assessed with Pittsburgh Sleep Quality Index at early pregnancy on average 18.20 (sd=1.73) weeks gestation (between 12.43–21.86 weeks gestation). Salivary cortisol was measured seven times a day for one day: upon waking, 15 minutes after awakening, 30 minutes after awakening, at 10 a. m., at noon, at 17 p. m., and at bedtime. Salivary cortisol samples were collected between gestation weeks 12–20, on average at 18.88 weeks’ gestation (sd=1.48). General linear model and mixed design analysis of variance were used to study the association of sleep difficulty and diurnal salivary cortisol. Anxiety and depression symptoms, maternal age and education were included as covariates in general linear model analyses. Results: The total number of different kinds of sleep difficulties was not associated with salivary cortisol upon waking or at bedtime or cortisol awakening response, mean diurnal cortisol concentration, diurnal cortisol slope or diurnal cortisol change. Some specific types of sleep difficulties were associated with diurnal cortisol. Namely, greater sleep latency was associated with higher awakening cortisol and higher mean cortisol concentration. Daytime dysfunction was associated with lower awakening cortisol level and sleep disturbance (physical symptoms, that disturb sleep) was associated with flatter diurnal cortisol slope. Conclusions: Even though the total number of different kinds of sleep difficulties was not associated with diurnal cortisol, the results of this thesis suggest a possible association between specific type of maternal sleep difficulties and diurnal cortisol during early pregnancy. Longitudinal study protocols are needed to identify the possible causal mechanism between possible associations of specific sleep difficulties with cortisol during pregnancy. To examine biological fetal programming mechanisms, follow up on offspring birth weight, cognitive development and mental health should be included in these studies.