Browsing by Author "Rash, Joshua, A."

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    Developmental origins of infant stress reactivity profiles: A multi-system approach
    (Wiley, 2016-03-08) Giesbrecht, Gerald; Rash, Joshua, A.; Thomas, Jenna, C.; Campbell, Tavis, S.; Letourneau, Nicole; Granger, Douglas, A.
    Background: This study tested the hypothesis that maternal physiological and psychological variables during pregnancy discriminate between theoretically informed infant stress reactivity profiles. Methods: The sample comprised 254 women and their infants. Maternal mood, salivary cortisol, respiratory sinus arrhythmia (RSA), and salivary α-amylase (sAA) were assessed at 15 and 32 weeks gestational age. Infant salivary cortisol, RSA, and sAA reactivity were assessed in response to a structured laboratory frustration task at 6-months of age. Infant responses were used to classify them into stress reactivity profiles using three different classification schemes: HPA-axis, autonomic, and multi-system. Discriminant function analyses evaluated the prenatal variables that best discriminated infant reactivity profiles within each classification scheme. Results: Maternal stress biomarkers, along with self-reported psychological distress during pregnancy discriminated between infant stress reactivity profiles. Conclusions: These results suggest that maternal psychological and physiological states during pregnancy have broad effects on the development of the infant stress response systems.
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    Full-term deliveries without antecedent labor reveal sex differences in umbilical cord glucocorticoid concentrations.
    (Elsevier, 2016-12) Giesbrecht, Gerald; Rash, Joshua, A.; Edwards, Heather, E.; Wynne-Edwards, Katherine, E.
    Background: Previous studies have shown that pregnant women have higher salivary cortisol levels when the fetus is female. These findings suggest a basis for the sex differences observed in many offspring outcomes after exposure to in utero stress, but it is not known if fetal adrenal glucocorticoid synthesis differs by sex. Methods: Arterial and venous umbilical cord blood samples were collected immediately after scheduled cesarean delivery (n = 52, 25 female). Cortisol and corticosterone concentrations were quantified by liquid chromatography coupled to tandem mass spectrometry. Results: Sex differences were observed for fetal arterial and venous cortisol and venous corticosterone, with higher levels present when the fetus was female. However, sex differences were not observed for fetal synthesis of cortisol, suggesting that the fetus does not control the differences observed in cord blood glucocorticoids. Conclusions: The presence of sex differences in umbilical cord glucocorticoid concentrations in the absence of sex differences in glucocorticoid synthesis by the fetal adrenal gland suggests that these differences have a maternal or placental origin. Thus, the in utero glucocorticoids in circulation are sex-specific and may have developmental importance for sex differences in psychiatric and neurodevelopment disorders that display sex biases.