title: Caesarean section per se does not increase the risk of offspring developing type 1 diabetes: a Swedish population-based study.
abstract: OBJECTIVE
  Some studies have revealed a relationship between Caesarean section (CS) and type 1 diabetes, while other studies have not. By using the Swedish paediatric quality register we investigated whether birth by CS is related to the risk of developing type 1 diabetes during childhood.
  
  
  METHODS
  All children diagnosed with type 1 diabetes from 2000 to 2012 and included in the register (n = 9,376) were matched with four controls by year, day of birth, sex and county of birth from the Swedish Medical Birth Register.
  
  
  RESULTS
  Overall, 13.5% of deliveries were by CS. By group, 14.7% of children who developed type 1 diabetes were delivered by CS compared with 13.3% of control children (p < 0.001). Mothers with diabetes more often gave birth by CS than mothers without diabetes (78.8% vs 12.7%, p < 0.001). In a logistic regression model adjusting for maternal age, maternal diabetes and BMI in early pregnancy, the OR for CS was 1.0. A child who developed type 1 diabetes and had a mother with type 1 diabetes at the time of delivery had the highest OR to have been born by CS. Children of mothers without diabetes, delivered by CS, had no increased risk of developing type 1 diabetes. Maternal diabetes was the strongest predictor of childhood diabetes (OR 3.4), especially if the mother had type 1 diabetes (OR 7.54).
  
  
  CONCLUSIONS
  CS had no influence on the risk of type 1 diabetes during childhood or adolescence. However, maternal diabetes itself strongly increased the risk of offspring developing type 1 diabetes.
authors: Department of Paediatrics and Department of Clinical and Experimental Medicine, Linköping University, S-581 85, Linköping, Sweden. ulf.samuelsson@regionostergotland.se.
authors: Ulf
authors: U
authors: Samuelsson
authors: Department of Paediatrics and Department of Clinical and Experimental Medicine, Linköping University, S-581 85, Linköping, Sweden.
authors: Nina
authors: N
authors: Lindell
authors: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors: Marie
authors: M
authors: Bladh
authors: Department of Paediatrics, Ryhov County Hospital, Jönköping, Sweden.|Futurum - Academy for Health and Care, Jönköping, Sweden.|Jönköping Academy for Improvement of Health and Welfare, Jönköping University, Jönköping, Sweden.
authors: Karin
authors: K
authors: Åkesson
authors: Department of Clinical Sciences, Lund University, Skane University Hospital, Lund, Sweden.
authors: Annelie
authors: A
authors: Carlsson
authors: Department of Obstetrics and Gynaecology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors: Ann
authors: A
authors: Josefsson
mesh_terms: D000293:Adolescent; D002585:Cesarean Section / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012042:Registries; D012307:Risk Factors; D013548:Sweden; D055815:Young Adult
keywords: Caesarean section; Epidemiology; Pregnancy; Sex; Type 1 diabetes