title: Prenatal parental separation and body weight, including development of overweight and obesity later in childhood.
abstract: BACKGROUND
  Early parental separation may be a stress factor causing a long-term alteration in the hypothalamic-pituitary-adrenal-axis activity possibly impacting on the susceptibility to develop overweight and obesity in offspring. We aimed to examine the body mass index (BMI) and the risk of overweight and obesity in children whose parents lived separately before the child was born.
  
  
  METHODS
  A follow-up study was conducted using data from the Aarhus Birth Cohort in Denmark and included 2876 children with measurements of height and weight at 9-11-years-of-age, and self-reported information on parental cohabitation status at child birth and at 9-11-years-of-age. Quantile regression was used to estimate the difference in median BMI between children whose parents lived separately (n = 124) or together (n = 2752) before the birth. We used multiple logistic regression to calculate odds ratio (OR) for overweight and obesity, adjusted for gender, parity, breast feeding status, and maternal pre-pregnancy BMI, weight gain during pregnancy, age and educational level at child birth; with and without possible intermediate factors birth weight and maternal smoking during pregnancy. Due to a limited number of obese children, OR for obesity was adjusted for the a priori confounder maternal pre-pregnancy BMI only.
  
  
  RESULTS
  The difference in median BMI was 0.54 kg/m2 (95% confidence intervals (CI): 0.10; 0.98) between children whose parents lived separately before birth and children whose parents lived together. The risk of overweight and obesity was statistically significantly increased in children whose parents lived separately before the birth of the child; OR 2.29 (95% CI: 1.18; 4.45) and OR 2.81 (95% CI: 1.05; 7.51), respectively. Additional, adjustment for possible intermediate factors did not substantially change the estimates.
  
  
  CONCLUSIONS
  Parental separation before child birth was associated with higher BMI, and increased risk of overweight and obesity in 9-11-year-old children; this may suggest a fetal programming effect or unmeasured difference in psychosocial factors between separated and non-separated parents.
authors.affiliation: Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Lena
authors.initials: L
authors.lastname: Hohwü
authors.affiliation: Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Jin Liang
authors.initials: JL
authors.lastname: Zhu
authors.affiliation: Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Lise
authors.initials: L
authors.lastname: Graversen
authors.affiliation: Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Jiong
authors.initials: J
authors.lastname: Li
authors.affiliation: Institute of Preventive Medicine, Bispebjerg and Frederiksbjerg Hospitals, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Thorkild I A
authors.initials: TI
authors.lastname: Sørensen
authors.affiliation: Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Carsten
authors.initials: C
authors.lastname: Obel
mesh_terms: D015992:Body Mass Index; D002648:Child; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D050177:Overweight / Q000453:epidemiology* / Q000209:etiology; D063766:Pediatric Obesity / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D015406:Single Parent