title: The role of prenatal exposures on body fat patterns at 7 years: Intrauterine programming or birthweight effects?
abstract: It remains unknown whether the effects of prenatal exposures on child's adiposity reflect entirely intrauterine programming. We aimed to assess the effects of maternal gestational weight gain, diabetes and smoking on the child's body fat patterns, disentangling the direct (through intrauterine programming) and indirect (through birthweight) effects.
  
  
  
  We included 4747 singleton 7-year-old children from the Generation XXI birth cohort (Porto, Portugal). At birth, maternal and newborn's characteristics were obtained. Anthropometrics were measured at age 7 years and body fat patterns were identified by principal component analysis. Path analysis was used to quantify direct, indirect and total effects of gestational weight gain, diabetes and smoking on body fat patterns. Pattern 1 was characterized by strong factor loadings with body mass index, fat mass index and waist-to-height ratio (fat quantity) and pattern 2 with waist-to-hip ratio, waist-to-thigh ratio, and waist-to-weight ratio (fat distribution). The positive total effect of maternal gestational weight gain and diabetes on the child's fat quantity was mainly through a direct pathway, responsible for 91.7% and 83.7% of total effects, respectively (β = 0.022; 95% Confidence Interval (CI): 0.017, 0.027; β = 0.041; 95% CI: -0.011, 0.093). No effects on fat distribution were found. Maternal prenatal smoking had a positive direct effect on patterns 1 and 2, explaining 94.9% and 76.1% of total effects, respectively.
  
  
  
  The effects of maternal gestational weight gain, diabetes and smoking on a child's fat quantity seem to be mainly through intrauterine programming. Maternal smoking also showed a positive direct effect on child's fat distribution.
authors.affiliation: EPI-Unit, Institute of Public Health, University of Porto, Porto, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Santos
authors.affiliation: EPI-Unit, Institute of Public Health, University of Porto, Porto, Portugal; Department of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School, Porto, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Severo
authors.affiliation: The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, The Netherlands; Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Gaillard
authors.affiliation: EPI-Unit, Institute of Public Health, University of Porto, Porto, Portugal; Department of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School, Porto, Portugal.
authors.forename: A C
authors.initials: AC
authors.lastname: Santos
authors.affiliation: EPI-Unit, Institute of Public Health, University of Porto, Porto, Portugal; Department of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School, Porto, Portugal.
authors.forename: H
authors.initials: H
authors.lastname: Barros
authors.affiliation: EPI-Unit, Institute of Public Health, University of Porto, Porto, Portugal; Department of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School, Porto, Portugal. Electronic address: acmatos@med.up.pt.
authors.forename: A
authors.initials: A
authors.lastname: Oliveira
mesh_terms: D050154:Adiposity; D000367:Age Factors; D001724:Birth Weight; D015992:Body Mass Index; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000503:physiopathology; D016640:Diabetes, Gestational / Q000503:physiopathology; D005260:Female; D047109:Fetal Development; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D063766:Pediatric Obesity / Q000209:etiology* / Q000503:physiopathology; D011174:Portugal; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D025341:Principal Component Analysis; D012044:Regression Analysis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D049629:Waist-Hip Ratio; D015430:Weight Gain
keywords: Birth weight; Body fat; Children; Cohort studies; Fetal programming; Path analysis