Prenatal paracetamol exposure and risk of wheeze at preschool age


  • Ethical approval: The study was approved by the ethics committee at the University of Gothenburg.

E Goksör, M.D., Department of Paediatrics, University of Gothenburg, Queen Silvia Children’s Hospital, SE-416 85 Gothenburg, Sweden. Tel: +46-31-343-40-00 | Fax: +46-31-84-36-53 | Email:


Aim:  To analyse the association between prenatal paracetamol exposure and preschool wheeze.

Methods:  Data were obtained from a prospective, longitudinal study of a cohort of children born in the region of western Sweden in 2003; 8176 families were randomly selected. The parents answered questionnaires at 6 and 12 months and at 4.5 years of age. The response rate was 55%, i.e. 4496 of the 5398 questionnaires distributed at 4.5 years (83%). Inhaled corticosteroid (ICS) treated wheeze during the last year was regarded as a proxy for doctor-diagnosed asthma. Episodic viral wheeze was defined as wheezing only with viral infections and multiple-trigger wheeze as wheezing also in between infections.

Results:  In the multivariate analysis, the risk of ICS-treated wheeze was increased by paracetamol (OR 1.6; 95% CI 1.01–2.6). Within the ICS-treated group, the effect was significant for multiple-trigger wheeze (OR 2.4; 1.2–4.8) but not for episodic viral wheeze (OR 1.1; 0.5–2.3).

Conclusion:  Prenatal paracetamol exposure was an independent risk factor for ICS-treated wheeze at preschool age, especially among children with ICS-treated multiple-trigger wheeze. Although the analysis adjusted for e.g. maternal asthma and antibiotic use, the possibility of residual confounding by maternal indication (respiratory illness) should be acknowledged.