Heartburn Drug Use During Pregnancy Raises Risk of IBD in Children

Despite the overall low risk, researchers urged caution and consideration before using heartburn drugs during pregnancy.

New research suggests that side effects of heartburn medications like Prilosec, Zantac and Pepcid AC during pregnancy may slightly increase the chance that a child later develops inflammatory bowel disease (IBD).

According to findings published in the journal JAMA Network Open on June 24, the increased risk of IBD appears to be small but statistically significant among children whose mothers used heartburn medications, such as Tagamet HB, Nexium or similar drugs, during pregnancy.

IBD refers to a group of conditions that cause chronic inflammation in the digestive tract. The two most common forms are Crohn’s disease and ulcerative colitis.

Crohn’s disease can cause inflammation through multiple layers of the bowel, while ulcerative colitis typically affects the innermost lining of the large intestine and can lead to ulcers. Both conditions may cause symptoms such as chronic diarrhea, abdominal pain, cramping, unexplained weight loss and persistent fatigue.

Heartburn Drugs During Pregnancy

Heartburn is common during pregnancy, and many women use acid-reducing medications to control symptoms. These include proton pump inhibitors, such as Prilosec, Prevacid and Nexium, which reduce acid production by blocking an enzyme system in the stomach lining, as well as H2 blockers, such as Pepcid AC, Zantac 360 and Tagamet HB, which lower the amount of acid the stomach produces.

Although these medications are widely used during pregnancy and are generally considered safe for expectant mothers, researchers have begun examining whether prenatal exposure may affect a child’s developing gut and immune system.

Those concerns were also raised in a 2023 study by Wake Forest University researchers, which found that use of heartburn medications during pregnancy was associated with a higher risk of digestive problems in infants, including inflammation of the esophagus.

In the latest study, researchers led by Dr. Jiyeon Oh, of Kyung Hee University College of Medicine in South Korea examined whether prenatal exposure to acid-suppressive medications was associated with a higher risk of inflammatory bowel disease among children. The researchers noted that proton pump inhibitors and H2 receptor antagonists are commonly used during pregnancy, but questions have been raised about whether these drugs may affect the developing gut microbiome and immune system, which are believed to play a role in pediatric IBD.

The researchers analyzed 2.6 million mother-child pairs from South Korea’s National Health Insurance Service, focusing on children born between 2010 and 2017, with follow-up through the end of 2023. Children exposed to acid-suppressive medications in the womb were matched with unexposed children at a 1-to-3 ratio, allowing researchers to compare later diagnoses of inflammatory bowel disease, Crohn’s disease and ulcerative colitis.

Overall, the findings showed a modest increase in IBD risk among children whose mothers used heartburn medications during pregnancy. After matching, prenatal exposure was associated with an 8% increased risk of IBD and a 10% increased risk of Crohn’s disease, but there was no statistically significant increase for ulcerative colitis. Researchers also found the absolute risk difference was very small and not statistically significant, measuring about 0.41 additional IBD cases per 1,000 children.

The study also found some differences by drug type and timing. Children exposed only to H2 blockers had a small increased risk of IBD and Crohn’s disease, while children exposed only to proton pump inhibitors had a higher estimated risk of IBD, although the Crohn’s disease estimate for PPIs alone was not statistically significant. The association appeared strongest for first-trimester exposure and for mothers who received two or more prescriptions during pregnancy.

However, when researchers compared siblings within the same families, they found no significant association between prenatal exposure to acid-suppressive medications and IBD, Crohn’s disease or ulcerative colitis. The authors said that finding may indicate that shared family or genetic factors, rather than the medications themselves, could explain at least part of the observed association.

Researchers concluded that any potential risk to children appears minimal and should be weighed against the need to treat significant heartburn or acid-related conditions during pregnancy. They indicated the findings support continued use of acid-suppressive medications when clinically necessary, while still encouraging caution and appropriate prescribing for pregnant women.