Taking heartburn medication while pregnant may increase your child’s risk of developing asthma, according to a review of studies recently published in the Journal of Allergy and Clinical Immunology.

The review looked at eight different studies with a combined total of more than 1,600,000 participants. It found that children whose mothers took H2 blockers such as Pepcid and Tagamet while pregnant had a 46% increased risk of asthma development. Children whose mothers took proton pump inhibitors such as Prilosec and Nexium had a 30% increased risk.

But don’t stop taking any medications just yet. “It is important to stress that this research is at a very early stage, and expectant [mothers] should continue to take any medication they need under the guidance of their doctor or nurse,” said Samantha Walker, policy and research director at Asthma UK. She went on to explain that they “don’t yet know if the heartburn medication itself is contributing to the development of asthma in children, or if there is a common factor we haven’t discovered yet that causes both heartburn in pregnant women and asthma in their children.”

However, the review’s lead author Dr Aziz Sheikh recommended that pregnant women manage their heartburn with lifestyle or diet changes when possible. And when medication is needed, he recommended first trying “milder treatments like chewable antacid tablets.”