RESUMEN
OBJECTIVE: The aim of the study was to investigate prospective, longitudinal associations between maternal prenatal cortisol response to an interpersonal stressor and child health for the subsequent 3 years. METHODS: One hundred twenty-three women expecting their first child provided salivary cortisol samples between 12 and 32 weeks of gestation (M (SD) = 22.4 (4.9) weeks) before and after a videotaped couple conflict discussion with their partner. Mothers reported on overall child health and several indicators of child illness (sick doctor visits, fevers, ear, and respiratory infections) when children were 6 months (n = 114), 1 (n = 116), and 3 (n = 105) years old. Associations between maternal prenatal cortisol reactivity and recovery and later child health at each of the three time points were analyzed using longitudinal regression models. RESULTS: Greater cortisol reactivity in response to the couple conflict discussion was associated with maternal self-report of better overall child health (p = .016, 95% CI = 0.06-1.30, Cohen's f = 0.045) across the study period. Greater cortisol reactivity was also associated with lower incidence rate ratios for maternal reports of sick doctor visits (incidence rate ratio 95% CI = 0.25-0.83, p = .006), fevers (95% CI = 0.25-0.73, p = .002), ear infections (95% CI = 0.25-0.58, p < .001), and respiratory infections (95% CI = 0.08-1.11, p = .073). Cortisol recovery was unrelated to study outcomes (all p's > 0.05). Maternal prenatal depressive symptoms moderated the association between cortisol reactivity and overall child health (p = .034, 95% CI = 0.07-1.87 for interaction term) but no other health outcomes (p's > 0.05). Among women with lower depressive symptoms, cortisol reactivity was not associated with overall child health; among women with higher levels of depressive symptoms, greater cortisol reactivity was associated with better overall child health. CONCLUSIONS: This study provides longitudinal evidence that greater maternal cortisol reactivity to a salient interpersonal stressor during pregnancy is associated with fewer child health problems and better maternal report of overall child health during infancy and into early childhood. TRIAL REGISTRATION: Clinicaltrials.gov ID NCT01901536.
Asunto(s)
Fiebre/epidemiología , Hidrocortisona/metabolismo , Otitis/epidemiología , Complicaciones del Embarazo/metabolismo , Efectos Tardíos de la Exposición Prenatal/epidemiología , Infecciones del Sistema Respiratorio/epidemiología , Estrés Psicológico/metabolismo , Adulto , Preescolar , Femenino , Humanos , Lactante , Estudios Longitudinales , Embarazo , Complicaciones del Embarazo/epidemiología , Primer Trimestre del Embarazo , Tercer Trimestre del Embarazo , Estudios Prospectivos , Saliva/química , Estrés Psicológico/epidemiología , Adulto JovenRESUMEN
BACKGROUND: Disrupted maternal prenatal cortisol production influences offspring development. Factors influencing the hypothalamic-pituitary-adrenal axis include social (e.g., stressful life events) and physical/chemical (e.g., toxic metals) pollutants. Mercury (Hg) is a common contaminant of fish and exposure is widespread in the US. No prior study has examined the joint associations of stress and mercury with maternal cortisol profiles in pregnancy. OBJECTIVES: To investigate potential synergistic influences of prenatal stress and Hg exposures on diurnal cortisol in pregnant women. METHODS: Analyses included 732 women (aged 27.4 ± 5.6 years) from a Mexico City pregnancy cohort. Participants collected saliva samples on two consecutive days (mean 19.52 ± 3.00 weeks gestation) and reported life stressors over the past 6 months. Hg was assessed in toe nail clippings collected during pregnancy. RESULTS: There were no main effects of Hg or psychosocial stress exposure on diurnal cortisol (ps > .20) but strong evidence of interaction effects on cortisol slope (interaction B = .006, SE = .003, p = .034) and cortisol at times 1 and 2 (interaction B = -.071, SE = .028, p = .013; B = -.078, SE = .032, p = .014). Women above the median for Hg and psychosocial stress exposure experienced a blunted morning cortisol response compared to women exposed to higher stress but lower Hg levels. CONCLUSIONS: Social and physical environmental factors interact to alter aspects of maternal diurnal cortisol during pregnancy. Research focusing solely on either domain may miss synergistic influences with potentially important consequences to the offspring.