title: Prenatal exposure to antibiotics, cesarean section and risk of childhood obesity.
abstract: OBJECTIVE
  Cesarean section (CS) and antibiotic use during pregnancy may alter normal maternal-offspring microbiota exchange, thereby contributing to aberrant microbial colonization of the infant gut and increased susceptibility to obesity later in life. We hypothesized that (i) maternal use of antibiotics in the second or third trimester of pregnancy and (ii) CS are independently associated with higher risk of childhood obesity in the offspring.
  
  
  METHODS
  Of the 727 mothers enrolled in the Northern Manhattan Mothers and Children Study, we analyzed the 436 mother-child dyads followed until 7 years of age with complete data. We ascertained prenatal antibiotic use by a questionnaire administered late in the third trimester, and delivery mode by medical record. We derived age- and sex-specific body mass index (BMI) z-scores using the CDC SAS Macro, and defined obesity as BMI z⩾95th percentile. We used binary regression with robust variance and linear regression models adjusted for maternal age, ethnicity, pre-gravid BMI, maternal receipt of public assistance, birth weight, sex, breastfeeding in the first year and gestational antibiotics or delivery mode.
  
  
  RESULTS
  Compared with children not exposed to antibiotics during the second or third trimester, those exposed had 84% (33-154%) higher risk of obesity, after multivariable adjustment. Second or third trimester antibiotic exposure was also positively associated with BMI z-scores, waist circumference and % body fat (all P<0.05). Independent of prenatal antibiotic usage, CS was associated with 46% (8-98%) higher offspring risk of childhood obesity. Associations were similar for elective and non-elective CS.
  
  
  CONCLUSIONS
  In our cohort, CS and exposure to antibiotics in the second or third trimester were associated with higher offspring risk of childhood obesity. Future studies that address the limitations of our study are warranted to determine if prenatal antibiotic use is associated with offspring obesity. Research is also needed to determine if alterations in neonatal gut microbiota underlie the observed associations.
authors.affiliation: 1] Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA [2] Institute of Human Nutrition and Department of Medicine, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA.
authors.forename: N T
authors.initials: NT
authors.lastname: Mueller
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA.
authors.forename: R
authors.initials: R
authors.lastname: Whyatt
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA.
authors.forename: L
authors.initials: L
authors.lastname: Hoepner
authors.affiliation: Department of Pediatrics, New York-Presbyterian Hospital, Columbia University Medical Center, New York, NY, USA.
authors.forename: S
authors.initials: S
authors.lastname: Oberfield
authors.affiliation: Division of Translational Medicine, New York University School of Medicine, New York, NY, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Dominguez-Bello
authors.affiliation: 1] Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA [2] Institute of Human Nutrition and Department of Medicine, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Widen
authors.affiliation: Department of Pediatrics, New York-Presbyterian Hospital, Columbia University Medical Center, New York, NY, USA.
authors.forename: A
authors.initials: A
authors.lastname: Hassoun
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA.
authors.forename: F
authors.initials: F
authors.lastname: Perera
authors.affiliation: Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA.
authors.forename: A
authors.initials: A
authors.lastname: Rundle
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001724:Birth Weight; D002585:Cesarean Section / Q000009:adverse effects* / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009035:Mothers; D063766:Pediatric Obesity / Q000209:etiology* / Q000517:prevention & control*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000517:prevention & control*; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D000900:Anti-Bacterial Agents