Led by Seif Shaheen, Professor of Respiratory Epidemiology at Barts and The London School of Medicine and Dentistry, the team examined data from the British Avon Longitudinal Study of Parents and Children (ALSPAC) which has followed 14,000 children since birth - beginning with their mothers' pregnancies and continuing into the children's 8th year.
Participating mothers reported on their use of paracetamol during pregnancy, as well as their child's exposure to the drug during infancy.
Shaheen and researchers found evidence suggesting that the risk of childhood asthma associated with prenatal paracetamol exposure depended on which variants of various antioxidant genes were present in the mother. In contrast, interactions between infant paracetamol use and similar gene variants in the child were not seen.
Shaheen added, "Our latest findings add further weight to the evidence implicating prenatal paracetamol exposure in the development of childhood asthma. However, ultimately a cause and effect relationship can only be confirmed through randomised clinical trials."
The finding has been published online in the Journal of Allergy and Clinical Immunology.