title: Maternal cortisol and stress are associated with birth outcomes, but are not affected by lipid-based nutrient supplements during pregnancy: an analysis of data from a randomized controlled trial in rural Malawi.
abstract: BACKGROUND
  Prenatal micronutrient supplements have been found to increase birth weight, but mechanisms for increased growth are poorly understood. Our hypotheses were that 1) women who receive lipid-based nutrient supplements (LNS) during pregnancy would have lower mean salivary cortisol concentration at 28 wk and 36 wk gestation compared to the multiple micronutrient (MMN) and iron-folic acid (IFA) supplement groups and 2) both salivary cortisol and perceived stress during pregnancy would be associated with shorter duration of gestation and smaller size at birth.
  
  
  METHODS
  Women were enrolled in the trial in early pregnancy and randomized to receive LNS, MMN, or iron-folic acid (IFA) supplements daily throughout pregnancy. At enrollment, 28 wk and 36 wk gestation, saliva samples were collected and their cortisol concentration was measured. Self-report of perceived stress was measured using questionnaires. Gestation duration was indicated by ultrasound dating and newborn anthropometric measurements (weight, length, head circumference) provided indicators of intrauterine growth.
  
  
  RESULTS
  Of the 1391 women enrolled in the trial, 1372, 906 and 1049 saliva samples were collected from women at baseline, 28 wk and 36 wk, respectively. There were no significant differences in mean cortisol concentrations by intervention group at 28 wk or 36 wk gestation. Cortisol concentrations were negatively associated with duration of gestation (Baseline: β = -0.05, p = 0.039; 36 wk: β = -0.04, p = 0.037) and birth weight (28 wk: β = -0.08, p = 0.035; 36 wk: β = -0.11, p = 0.003) but not associated with length-for-age or head circumference-for-age z-scores. Perceived stress at 36 wk was significantly associated with shorter newborn LAZ (p = 0.001). There were no significant associations with the risk of small for gestational age, preterm birth, or low birth weight.
  
  
  CONCLUSIONS
  Maternal salivary cortisol concentration was strongly associated with birth weight and duration of gestation in rural Malawi, but these data do not support the hypothesis that LNS provision to pregnant women would influence their salivary cortisol concentrations.
  
  
  BACKGROUND
  Clinicaltrials.gov identifier NCT01239693.
authors.affiliation: Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, USA. cpstewart@ucdavis.edu.
authors.forename: Christine P
authors.initials: CP
authors.lastname: Stewart
authors.affiliation: Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, USA. boaks@ucdavis.edu.
authors.forename: Brietta M
authors.initials: BM
authors.lastname: Oaks
authors.affiliation: Western Human Nutrition Research Center, USDA-ARS, Davis, CA, USA. Kevin.Laugero@ARS.USDA.GOV.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Laugero
authors.affiliation: Department for International Health, USDA-ARS, Tampere, Finland. ulla.ashorn@uta.fi.
authors.forename: Ulla
authors.initials: U
authors.lastname: Ashorn
authors.affiliation: Department for International Health, USDA-ARS, Tampere, Finland. ulla.harjunmaa@uta.fi.
authors.forename: Ulla
authors.initials: U
authors.lastname: Harjunmaa
authors.affiliation: Department of Community Health, University of Malawi College of Medicine, Blantyre, Malawi. chizakumwenda@yahoo.co.uk.
authors.forename: Chiza
authors.initials: C
authors.lastname: Kumwenda
authors.affiliation: Department of Community Health, University of Malawi College of Medicine, Blantyre, Malawi. davidchaima@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Chaima
authors.affiliation: Department of Community Health, University of Malawi College of Medicine, Blantyre, Malawi. ken.maleta@gmail.com.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Maleta
authors.affiliation: Department for International Health, USDA-ARS, Tampere, Finland. per.ashorn@uta.fi.|Department of Paediatrics, Tampere University Hospital, Tampere, Finland. per.ashorn@uta.fi.
authors.forename: Per
authors.initials: P
authors.lastname: Ashorn
authors.affiliation: Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, USA. kgdewey@ucdavis.edu.
authors.forename: Kathryn G
authors.initials: KG
authors.lastname: Dewey
mesh_terms: D000293:Adolescent; D000328:Adult; D001724:Birth Weight / Q000187:drug effects*; D019587:Dietary Supplements / Q000592:standards*; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D007231:Infant, Newborn; D007501:Iron / Q000627:therapeutic use; D008295:Malawi; D039382:Maternal Nutritional Physiological Phenomena; D018977:Micronutrients / Q000627:therapeutic use*; D008875:Middle Aged; D011247:Pregnancy; D012424:Rural Population; D057566:Self Report; D013315:Stress, Psychological; D055815:Young Adult
chemical_list: D018977:Micronutrients; D005492:Folic Acid; D007501:Iron; D006854:Hydrocortisone