Is antacid use during pregnancy tied to childhood asthma?

Last Updated: 2018-01-11

By Lisa Rapaport

(Reuters Health) - Pregnant women who take antacids may be more likely to have children who go on to develop asthma than their counterparts who don't take these medications, a research review suggests.

Up to four in five pregnant women suffer from heartburn or acid indigestion from gastroesophageal reflux disease (GERD), the study authors note in Pediatrics. Research to date has offered a mixed safety picture of drugs many pregnant women take for GERD: proton pump inhibitors (PPIs), including Prilosec and Prevacid, and histamine-2 receptor antagonists (H2RAs) such as Pepcid and Zantac.

For the current analysis, published online January 11 in Pediatrics, researchers examined data from eight previously published studies with a total of more than 1.6 million participants. Overall, pregnant women who used PPIs and H2RAs were 45% more likely to have children with asthma than women who didn't use these drugs during pregnancy.

"All women should use caution when taking acid-suppressing drugs during pregnancy," said senior study author Dr. Huahao Shen of Zhejiang University in China.

None of the smaller studies included in the current analysis assessed the risk of childhood asthma associated with antacids by randomly assigning some pregnant women to use the drugs and others to avoid them.

While this type of controlled experiment could prove whether or not antacids directly cause childhood asthma, it's not ethical to test drugs on pregnant women that might harm their babies.

Instead, the studies included in the current analysis relied on information from records like government health registries or prescription databases. These studies included women in Sweden, Denmark, the Netherlands, Israel and the UK.

Pregnant women who used PPIs were 34% more likely to have children with asthma than their counterparts who didn't take these drugs, the study found.

With H2RAs, the risk of childhood asthma increased 57%.

Researchers didn't report the absolute risk of childhood asthma associated with these medications, so it's not clear how many children might develop this disease as a result of their mothers using antacids during pregnancy instead of from other causes.

It's also still not clear whether the increased asthma risk stems from the antacids themselves, or the underlying GERD that leads women to take those drugs, researchers note in an editorial accompanying the study.

Another limitation is that many of the studies in the analysis only followed children through preschool or early childhood, and some asthma cases aren't diagnosed until adolescence or adulthood.

Even though these results are not definitive, women may still want to consider other options to relieve heartburn and indigestion, Shen said by email. Other medications that may ease these symptoms include Pepto Bismol, domperidone (Motilium) and hydrotalcite, he said.

Roughly one in 10 U.S. children have asthma, according to the Centers for Disease Control and Prevention. Common causes of asthma include indoor allergens like dust mites and pet dander, outdoor allergens like pollen and mold, tobacco smoke, air pollution and chemicals in the workplace, according to the World Health Organization.

Based on the current study results, women shouldn't jump to the conclusion that they must avoid antacids during pregnancy, said Dr. Bronwyn Brew, coauthor of the accompanying editorial and a researcher at the Karolinska Institute in Stockholm, Sweden.

"To reduce the risk of asthma in children the risk factors to be avoided that we do have robust medical evidence for are: avoiding smoking during pregnancy and early childhood both for the mother and caregivers, maternal weight gain and obesity in pregnancy, and maternal stress in pregnancy," Brew said by email.

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Pediatrics 2018.