title: Gestational age and newborn size according to parental social mobility: an intergenerational cohort study.
abstract: BACKGROUND
  We examined the associations between socioeconomic trajectories from birth to adulthood and gestational age and birth size in the next generation, using linked data from two population-based birth cohorts carried out in a Brazilian city. By comparing socioeconomic trajectories of mothers and fathers, we attempted to identify-specific effects of maternal and paternal socioeconomic trajectory on offspring birth weight, birth length, head circumference and gestational age at birth.
  
  
  METHODS
  2 population-based birth cohort studies were carried out in 1982 and 2004 in Pelotas (Brazil); 156 mothers and 110 fathers from the earlier cohort had children in 2004. Gestational age and birth length, weight and head circumference were measured. Analyses were carried out separately for mothers and fathers. Mediation analyses assessed the role of birth weight and adult body mass index (BMI).
  
  
  RESULTS
  Among mothers, but not for fathers, childhood poverty was strongly associated with smaller size in the next generation (about 400 g in weight and 1.5 cm in height) and shorter gestations (about 2 weeks). Adult poverty did not play a role. For mothers, the associations with gestational age, birth length and weight-but not with head circumference-persisted after adjusting for maternal birth weight and for the height and weight of the grandmother. Maternal birth weight did not mediate the observed associations, but high maternal BMI in adulthood was partly responsible for the association with gestational age.
  
  
  CONCLUSIONS
  Strong effects of early poverty on gestational age and birth size in the next generation were observed among mothers, but not among fathers. These findings suggest a specific maternal effect of socioeconomic trajectory, and in particular of early poverty on offspring size and duration of pregnancy.
authors.affiliation: Post-Graduate Programme in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Denise P
authors.initials: DP
authors.lastname: Gigante
authors.affiliation: Post-Graduate Programme in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Bernardo L
authors.initials: BL
authors.lastname: Horta
authors.affiliation: Post-Graduate Programme in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil Preventive Medicine Department, Sao Paulo University.
authors.forename: Alicia
authors.initials: A
authors.lastname: Matijasevich
authors.affiliation: Post-Graduate Programme in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Christian Loret de
authors.initials: CL
authors.lastname: Mola
authors.affiliation: Post-Graduate Programme in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Aluisio J D
authors.initials: AJ
authors.lastname: Barros
authors.affiliation: Post-Graduate Programme in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Ina S
authors.initials: IS
authors.lastname: Santos
authors.affiliation: Post-Graduate Programme in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil Post-Graduate Programme in Health and Behaviour, Catholic University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Barros
authors.affiliation: Post-Graduate Programme in Epidemiology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Cesar G
authors.initials: CG
authors.lastname: Victora
mesh_terms: D000328:Adult; D001724:Birth Weight; D015992:Body Mass Index; D049628:Body Size; D001938:Brazil; D015331:Cohort Studies; D004522:Educational Status; D005191:Family Characteristics; D005220:Fathers / Q000706:statistics & numerical data*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009035:Mothers / Q000706:statistics & numerical data*; D011203:Poverty; D011247:Pregnancy; D012044:Regression Analysis; D012937:Social Mobility; D013995:Time
keywords: Cohort studies; Lifecourse / Childhood Circumstances; Social and life-course epidemiology