First evidence of a possible association between gastric acid suppression during pregnancy and childhood asthma: a population-based register study

Clin Exp Allergy. 2009 Feb;39(2):246-53. doi: 10.1111/j.1365-2222.2008.03125.x. Epub 2008 Dec 9.


Background: Recent data in mice suggest that acid suppression during pregnancy yields offspring with type 2 T helper-dominant immunity, suggesting a predisposition for allergy.

Objective: To determine the association of in utero exposure to acid-suppressive medications and the subsequent development of allergic diseases in children.

Methods: We studied a population-based observational cohort formed by linking data from three Swedish national healthcare registers: the Medical Birth Register, the Hospital Discharge Register, and the Swedish Prescribed Drug Register. Main outcome measures included a hospital discharge diagnosis of an allergic disease or prescription for asthma medications, epinephrine auto-injectors, antihistamines or steroid ointments in children. Data were analysed using the Mantel-Haenszel procedure.

Results: Twenty-nine thousand four hundred and ninety (5.03%) children had a discharge diagnosis of allergy or prescriptions for allergy medications. Five thousand six hundred and forty-five (0.96%) children had been exposed to acid suppression therapy during pregnancy; of these, 405 (0.07%) were treated for allergic diseases. Exposure to acid-suppressive medications in utero was associated with an increased odds ratio (OR) for developing allergy (OR 1.43, 95% confidence interval (95% CI) 1.29-1.59). We observed this association irrespective of the type of drug, time of exposure during pregnancy, and maternal history of allergy. The use of maternal acid-suppressive medication was associated with an increased OR for the development of childhood asthma (3.7% in the population at large vs. 5.6% in exposed children, OR 1.51, 95% CI 1.35-1.69), but not for other allergic diseases.

Conclusion: These data provide first evidence of a significant association between in utero exposure to acid-suppressive drugs and the risk of developing childhood asthma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antacids / adverse effects*
  • Antacids / therapeutic use
  • Anti-Asthmatic Agents / therapeutic use
  • Anti-Ulcer Agents / adverse effects*
  • Anti-Ulcer Agents / therapeutic use
  • Asthma / epidemiology*
  • Asthma / etiology*
  • Child
  • Child, Preschool
  • Cohort Studies
  • Databases, Factual
  • Female
  • Histamine H2 Antagonists / adverse effects
  • Histamine H2 Antagonists / therapeutic use
  • Humans
  • Hypersensitivity / epidemiology
  • Infant
  • Infant, Newborn
  • Medical Records
  • Odds Ratio
  • Pregnancy
  • Prenatal Exposure Delayed Effects / epidemiology*
  • Proton Pump Inhibitors / adverse effects
  • Proton Pump Inhibitors / therapeutic use
  • Registries*
  • Risk Factors
  • Sweden / epidemiology


  • Antacids
  • Anti-Asthmatic Agents
  • Anti-Ulcer Agents
  • Histamine H2 Antagonists
  • Proton Pump Inhibitors