title: Use of acid-suppressive drugs in pregnancy and the risk of childhood asthma: bidirectional crossover study using the general practice research database.
abstract: BACKGROUND
  Recent studies have reported an association between maternal use of gastric acid-suppressive drugs during pregnancy and asthma in the offspring, but the association could have been confounded by unmeasured risk factors.
  
  
  OBJECTIVE
  We assessed the association between the use of acid-suppressive drugs during pregnancy and the risk of developing childhood asthma using a bidirectional crossover design.
  
  
  METHODS
  Mother-infant matched sets in the UK General Practitioners Research Database were used to identify children with a drug-treated asthma diagnosis during the years 2006-2010 who were matched to a sibling without asthma as controls. Primary exposure was use of any anti-suppressive drug during pregnancy, and subgroup analyses were conducted according to drug class (e.g. proton pump inhibitors or histamine 2 receptor antagonists) and trimester. Conditional logistic regression was used to estimate odds ratios (OR) with their corresponding 95 % confidence intervals (CIs).
  
  
  RESULTS
  A total of 1,874 children with asthma and 1,874 control siblings were included in the analysis. The exposure rate among case and control pregnancies was 22 and 20 %, respectively. After adjustments for gender, birth order, mother's age and general practice visits, the exposure to any gastric-acid suppressive drug during pregnancy slightly increased the risk for developing asthma (OR 1.23, 95 % CI 1.01-1.51; p = 0.042). A trend towards increased risks was observed for those who used proton pump inhibitors and/or histamine 2 receptor antagonists (adjusted OR 1.72, 95 % CI 1.00-2.98; p = 0.048).
  
  
  CONCLUSIONS
  These findings lend support to the emerging evidence that exposure to acid-suppressive drugs during pregnancy is associated with childhood asthma. More basic research is now warranted to investigate the mechanisms.
authors.affiliation: Pharmacoepidemiology and Pharmacoeconomics, Department of Pharmacy, University Groningen, Deusinglaan 1, 9713 AV, Groningen, The Netherlands, e.hak@rug.nl.
authors.forename: Eelko
authors.initials: E
authors.lastname: Hak
authors.forename: Bianca
authors.initials: B
authors.lastname: Mulder
authors.forename: Catharina C M
authors.initials: CC
authors.lastname: Schuiling-Veninga
authors.forename: Tjalling W
authors.initials: TW
authors.lastname: de Vries
authors.forename: Susan S
authors.initials: SS
authors.lastname: Jick
mesh_terms: D000328:Adult; D000863:Antacids / Q000008:administration & dosage / Q000009:adverse effects*; D001249:Asthma / Q000139:chemically induced* / Q000453:epidemiology; D002675:Child, Preschool; D016001:Confidence Intervals; D018592:Cross-Over Studies; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D058006:General Practice / Q000706:statistics & numerical data; D006801:Humans; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced* / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000863:Antacids
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