Heartburn Drugs in Pregnancy Link to Child Asthma

Peter Russell

January 09, 2017

Mothers who take some types of heartburn medication during pregnancy may increase the risk of their children developing asthma, according to a study.

Heartburn is caused when stomach acid leaks into the oesophagus – the tube that connects the stomach to the throat.

Heartburn is common during pregnancy, particularly during the second and third trimesters. It may occur because of changing hormone levels or by the expanding womb pressing on the stomach.

Acid-Blocking Medicines

Women who experience heartburn may be offered antacids to neutralise stomach acid, and these are sometimes combined with alginates that form a foam barrier between the stomach acid and the oesophagus to dampen down any reflux.

Additionally, medicines called H2-receptor antagonists and proton pump inhibitors may be prescribed to help block acid reflux. Some of these medicines are available to buy over-the-counter. They are considered safe to use in pregnancy because they do not affect development of the baby.

However, some research has suggested that these acid-blocking medicines may increase the risk of allergies in the unborn baby because they can impact on the immune system. Studies to investigate a link have been inconclusive.

A research team led by the University of Edinburgh and the University of Tampere in Finland reviewed 8 previous studies involving more than 1.3 million children. These studies contained information on symptoms and prescriptions. The researchers were able to link the mothers to the future health of their children.

They found that children born to mothers who had been prescribed acid-blocking medicines during pregnancy were at least one third more likely to have visited a doctor for symptoms of asthma than those whose mothers had not taken these drugs.

The researchers stress that advice to pregnant mothers on managing heartburn should not change based on their findings alone.

'More Research Is Needed'

Professor Aziz Sheikh, co-director of the Asthma UK Centre for Applied Research at the University of Edinburgh, says in a statement: "Our study reports an association between the onset of asthma in children and their mothers' use of acid-suppressing medication during pregnancy. It is important to stress that this association does not prove that the medicines caused asthma in these children and further research is needed to better understand this link."

Commenting on the findings in a statement, Dr Samantha Walker, director of policy and research at Asthma UK, says: "It is important to stress that this research is at a very early stage and expectant mums should continue to take any medication they need under the guidance of their doctor or nurse.

"We don't yet know if the heartburn medication itself is contributing to the development of asthma in children, or if there is common factor we haven't discovered yet that causes both heartburn in pregnant women and asthma in their children. The study points us towards something that needs further investigation, which is why we need to see more research carried out into the causes of asthma, a condition that affects 5.4 million people in the UK alone."

The study is published in the Journal of Allergy and Clinical Immunology.


Acid-suppressive medications during pregnancy and risk of asthma and allergy in children: A systematic review and meta-analysis, R Devine et al, Letter to the editor, Journal of Allergy and Clinical Immunology

University of Edinburgh