title: Planned Cesarean Delivery at Term and Adverse Outcomes in Childhood Health.
abstract: OBJECTIVE
  Planned cesarean delivery comprises a significant proportion of births globally, with combined rates of planned and unscheduled cesarean delivery in a number of regions approaching 50%. Observational studies have shown that offspring born by cesarean delivery are at increased risk of ill health in childhood, but these studies have been unable to adjust for some key confounding variables. Additionally, risk of death beyond the neonatal period has not yet been reported for offspring born by planned cesarean delivery.
  
  
  OBJECTIVE
  To investigate the relationship between planned cesarean delivery and offspring health problems or death in childhood.
  
  
  METHODS
  Population-based data-linkage study of 321,287 term singleton first-born offspring born in Scotland, United Kingdom, between 1993 and 2007, with follow-up until February 2015.
  
  
  METHODS
  Offspring born by planned cesarean delivery in a first pregnancy were compared with offspring born by unscheduled cesarean delivery and with offspring delivered vaginally.
  
  
  METHODS
  The primary outcome was asthma requiring hospital admission; secondary outcomes were salbutamol inhaler prescription at age 5 years, obesity at age 5 years, inflammatory bowel disease, type 1 diabetes, cancer, and death.
  
  
  RESULTS
  Compared with offspring born by unscheduled cesarean delivery (n = 56,015 [17.4%]), those born by planned cesarean delivery (12,355 [3.8%]) were at no significantly different risk of asthma requiring hospital admission, salbutamol inhaler prescription at age 5 years, obesity at age 5 years, inflammatory bowel disease, cancer, or death but were at increased risk of type 1 diabetes (0.66% vs 0.44%; difference, 0.22% [95% CI, 0.13%-0.31%]; adjusted hazard ratio [HR], 1.35 [95% CI, 1.05-1.75]). In comparison with children born vaginally (n = 252,917 [78.7%]), offspring born by planned cesarean delivery were at increased risk of asthma requiring hospital admission (3.73% vs 3.41%; difference, 0.32% [95% CI, 0.21%-0.42%]; adjusted HR, 1.22 [95% CI, 1.11-1.34]), salbutamol inhaler prescription at age 5 years (10.34% vs 9.62%; difference, 0.72% [95% CI, 0.36%-1.07%]; adjusted HR, 1.13 [95% CI, 1.01-1.26]), and death (0.40% vs 0.32%; difference, 0.08% [95% CI, 0.02%-1.00%]; adjusted HR, 1.41 [95% CI, 1.05-1.90]), whereas there were no significant differences in risk of obesity at age 5 years, inflammatory bowel disease, type 1 diabetes, or cancer.
  
  
  CONCLUSIONS
  Among offspring of women with first births in Scotland between 1993 and 2007, planned cesarean delivery compared with vaginal delivery (but not compared with unscheduled cesarean delivery) was associated with a small absolute increased risk of asthma requiring hospital admission, salbutamol inhaler prescription at age 5 years, and all-cause death by age 21 years. Further investigation is needed to understand whether the observed associations are causal.
authors.affiliation: Division of Applied Health Sciences, University of Aberdeen, Aberdeen, United Kingdom.
authors.forename: Mairead
authors.initials: M
authors.lastname: Black
authors.affiliation: Division of Applied Health Sciences, University of Aberdeen, Aberdeen, United Kingdom.
authors.forename: Siladitya
authors.initials: S
authors.lastname: Bhattacharya
authors.affiliation: Diabetes Research Unit, NHS Grampian, Aberdeen, United Kingdom.
authors.forename: Sam
authors.initials: S
authors.lastname: Philip
authors.affiliation: Tommy's Centre for Maternal and Fetal Health, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Norman
authors.affiliation: Division of Applied Health Sciences, University of Aberdeen, Aberdeen, United Kingdom.
authors.forename: David J
authors.initials: DJ
authors.lastname: McLernon
mesh_terms: D000328:Adult; D001249:Asthma / Q000453:epidemiology; D002585:Cesarean Section / Q000009:adverse effects*; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology; D017558:Elective Surgical Procedures; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology; D009026:Mortality / Q000639:trends; D009369:Neoplasms / Q000453:epidemiology; D063766:Pediatric Obesity / Q000453:epidemiology; D011247:Pregnancy; D012306:Risk; D012606:Scotland; D006113:United Kingdom / Q000453:epidemiology