Use of acid suppressants in pregnancy may increase risk of childhood asthma
A recent systematic review (Paediatrics 2018;141(2):e20170889) indicates that maternal use of proton-pump inhibitors and H2-receptor antagonists in pregnancy may increase the risk of asthma in the child.
The authors conducted a meta-analysis of eight population-based studies and found that acid suppressant use during pregnancy was associated with a significantly increased risk of childhood asthma in the offspring (relative risk (RR) 1.45; 95% CI 1.35–1.56; p<0.00001) compared with no use. The increased risk occurred with both use of H2-receptor antagonists (RR 1.57) and proton-pump inhibitors (RR 1.34).
Gastro-oesophageal reflux disease (GORD) is common in pregnancy, and acid suppressants such as proton-pump inhibitors and H2-receptor antagonists are often prescribed to manage the condition. For many of these agents, the manufacturers’ advice is to avoid their use during pregnancy, although the summary of product characteristics for omeprazole states that it can be used in pregnancy.
One possible theory for the association between use of these drugs in pregnancy and childhood asthma is that acid suppression may lead to reduced activation of proteases, which are needed to digest proteins, thus increasing immune sensitisation to food proteins. However, the studies included in the meta-analysis did not adjust for all confounding factors, and it is possible that GORD itself and not its treatment may increase the risk of asthma in the child. Further studies are therefore needed; nevertheless, the authors recommend caution when deciding whether to use acid suppressant drugs in pregnancy.