title: Surgically induced interpregnancy weight loss and prevalence of overweight and obesity in offspring.
abstract: BACKGROUND
  According to the fetal overnutrition hypothesis, obesity in pregnancy predisposes the offspring to obesity. Previous studies have suggested that after biliopancreatic surgery for obesity, the offspring is less likely to be obese. This study aims to further compare the BMI development of children born before and after maternal surgical weight loss.
  
  
  METHODS
  Women with at least one child born before and one child born after bariatric surgery were identified by record-linkage. Information about maternal BMI was extracted from medical records, as was information about the children's BMI from birth to 10 years of age. We retrieved BMI data at four years of age for 340 children, born to 223 women (164 children born before surgery (BS), 176 children born after surgery (AS)). We evaluated prevalence of overweight/obesity and mean BMI in children born BS and AS at the ages of four, six and ten using GEE regression models. For 71 families, where we had complete data on mother and both children, we used a fixed-effects regression model to explore the association between differences in maternal BMI in w10 of the pre- and post-operative pregnancies with siblings' BMI differences at age four.
  
  
  RESULTS
  In no age group did we see a significantly reduced prevalence of overweight/obesity AS. For 10-year-old girls, the AS group had significantly higher rates of obesity. There was no association between differences in maternal BMI in early pregnancy and differences in siblings' BMI at four years of age (β = -0.01, CI 95% = -0.11; 0.09).
  
  
  CONCLUSIONS
  We have been unable to demonstrate any effect of bariatric surgery on weight development in offspring. It seems unlikely that restrictive bariatric surgery conveys a protective effect in offspring with regards to obesity.
authors.affiliation: Child and Adolescent Public Health Epidemiology, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mikaela
authors.initials: M
authors.lastname: Willmer
authors.affiliation: Child and Adolescent Public Health Epidemiology, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Berglind
authors.affiliation: Institute of Preventive Medicine, Bispebjerg and Frederiksberg University Hospital, Copenhagen, The Capital Region, Denmark ; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Thorkild I A
authors.initials: TI
authors.lastname: Sørensen
authors.affiliation: Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Näslund
authors.affiliation: Child and Adolescent Public Health Epidemiology, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Tynelius
authors.affiliation: Child and Adolescent Public Health Epidemiology, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Finn
authors.initials: F
authors.lastname: Rasmussen
mesh_terms: D050110:Bariatric Surgery; D015992:Body Mass Index; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009765:Obesity / Q000453:epidemiology* / Q000601:surgery*; D011247:Pregnancy; D015995:Prevalence; D013548:Sweden / Q000453:epidemiology; D015431:Weight Loss