title: Cesarean birth is not associated with early childhood body mass index.
abstract: Cesarean birth leads to a markedly different microbiome compared to vaginal birth, and the microbiome has been implicated in childhood obesity. Among mothers who had a previous cesarean, we compared anthropometry of 3- to 6-year-old children who were subsequently born by cesarean section versus vaginal birth. This large population-based study involved linking de-identified administrative perinatal and anthropometric data. Children's weight and height were collected at community-based clinics and converted to age- and sex-adjusted z-scores of height-for-age (HFAz), weight-for-age (WFAz) and BMI-for-age (BMIz). The average treatment effect (ATE) of cesarean versus vaginal birth was calculated from augmented inverse probability weighted analyses accounting for a wide range of confounding variables. There was little evidence of an effect of cesarean birth on HFAz (ATE = 0.26 95%CI -0.35, 0.87, n = 3993), WFAz (ATE = 0.35, 95%CI -0.19, 0.89, n = 4817) or BMIz (ATE = 0.11, 95%CI -0.25, 0.46, n = 3909). Cesarean section was not associated with anthropometry among children aged 3-6 years.
authors.affiliation: School of Public Health, University of Adelaide, Adelaide, Australia.
authors.forename: L G
authors.initials: LG
authors.lastname: Smithers
authors.affiliation: The Robinson Institute, School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, Australia.|The South Australian Health and Medical Research Institute, Adelaide, Australia.
authors.forename: B W
authors.initials: BW
authors.lastname: Mol
authors.affiliation: Indigenous Oral Health Unit, University of Adelaide, Adelaide, Australia.
authors.forename: L
authors.initials: L
authors.lastname: Jamieson
authors.affiliation: School of Public Health, University of Adelaide, Adelaide, Australia.|School of Social and Community Medicine, University of Bristol, Bristol, England, UK.
authors.forename: J W
authors.initials: JW
authors.lastname: Lynch
mesh_terms: D000328:Adult; D000886:Anthropometry / Q000379:methods*; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D009035:Mothers; D011247:Pregnancy; D012307:Risk Factors; D015430:Weight Gain
keywords: Anthropometry; body mass index; cesarean section; vaginal birth