title: Allostatic load may not be associated with chronic stress in pregnant women, NHANES 1999-2006.
abstract: OBJECTIVE
  Pregnant women are generally excluded from studies that measure allostatic load (AL) because there is concern that the changing levels of AL-related biomarkers during pregnancy do not reflect a woman's true AL. The goal of this study was to determine whether AL can be measured in a meaningful way during pregnancy.
  
  
  METHODS
  The National Health and Nutrition Examination Survey (NHANES) is a nationally representative, cross-sectional survey of the U.S. civilian population. AL was based on the distributions of 10 biomarkers in pregnant (n = 1138) and nonpregnant (n = 4993) women aged 15 to 44 from NHANES (1999-2006).
  
  
  RESULTS
  The distribution of each AL-related biomarker differed significantly between pregnant and nonpregnant women (P < .01). Among nonpregnant women, high AL findings were consistent with previous studies (e.g., higher AL in women who are black, are older, and who have lower incomes). However, these associations were not seen in pregnant women.
  
  
  CONCLUSIONS
  Our results suggest that the various biomarkers that comprise AL may reflect proximal factors in pregnancy more strongly than they represent exposure to chronic stress over a woman's lifetime. Therefore, our approach to measuring AL may not provide meaningful information about chronic stress in pregnant women without further consideration of pregnancy-related factors.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, University of Maryland, College Park, MD, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Morrison
authors.forename: Edmond D
authors.initials: ED
authors.lastname: Shenassa
authors.forename: Pauline
authors.initials: P
authors.lastname: Mendola
authors.forename: Tongtong
authors.initials: T
authors.lastname: Wu
authors.forename: Kenneth
authors.initials: K
authors.lastname: Schoendorf
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D052636:Allostasis / Q000502:physiology*; D015415:Biomarkers / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D009749:Nutrition Surveys; D011159:Population Surveillance; D011247:Pregnancy; D011248:Pregnancy Complications; D037841:Pregnant People / Q000523:psychology*; D012307:Risk Factors; D012959:Socioeconomic Factors; D013315:Stress, Psychological / Q000523:psychology*; D055815:Young Adult
chemical_list: D015415:Biomarkers