What Causes Heartburn During Pregnancy?

Pregnancy is an exciting time for expecting mothers. Yet each trimester brings a multitude of challenges due to the demands of a growing baby, including fatigue and morning sickness.¹ While mood swings and food cravings are common pregnancy topics, less is said about the toll it takes on basic bodily functions—including how the digestive system processes food when there’s a baby on board.¹

The reality is that many pregnant women experience heartburn, an uncomfortable, burning sensation in the chest that results from acid backing up in the esophagus.² Heartburn can be very uncomfortable and getting quick relief is important to avoid further distress. Here’s what you should know about the condition and its solutions.

What Is Heartburn?

Most adults, at one point or another, will experience heartburn or acid reflux. About 20 percent of Americans who have a more serious version, known as gastroesophageal reflux disease (GERD), experience heartburn more than twice a week that can last for several weeks in a row. People that are overweight or obese, take certain medications, or smoke (or are exposed to second-hand smoke) are at higher risk for GERD.³ If you are experiencing GERD, talk to your doctor about the prescription treatment options that are right for you.

The direct cause of heartburn comes from the weakening of the lower esophageal sphincter (LES), a valve between your esophagus and stomach that lets food pass from one to the other.² Normally, the valve works as a one-way street, remaining closed in the other direction to prevent food or stomach acid from backing up in the esophagus. However, with heartburn, the valve does not close tightly enough. This allows stomach acid, which helps break down food as it passes through, to travel back up to the esophagus, leading to an uncomfortable burning sensation.²

Possible Causes of Heartburn

Certain types of foods, most notably of the spicy variety, can contribute to heartburn. However, even foods like tomato products, peppermint, and chocolate can trigger these symptoms.² Heartburn may also be caused by daily habits and lifestyle choices, such as exercise routines and the type of clothes worn (more constricting apparel increases heartburn risk.)^{4, 5}

What Causes Heartburn During Pregnancy?

Up to 50 percent of women experience symptoms of heartburn during pregnancy, usually in the second and third trimesters.⁶ Along with the triggers listed above, pregnant women experience heartburn due to hormonal changes, particularly due to an increase in progesterone, which prepares the body for childbirth by acting as a muscle relaxer.^{6, 7} An unintended side effect is that muscles around the LES can relax too much, resulting in a faulty valve that lets stomach acid back up in the esophagus. As the baby grows, women experience more pressure on the stomach and a crowding of the abdomen.⁶ This pressure can also cause the LES to weaken.

Heartburn Treatment for Pregnant Women

Lifestyle and dietary changes, such as avoiding certain foods and eating smaller portions throughout the day, can lower the chances of heartburn.⁸ But for women who are still experiencing discomfort, an over-the-counter antacid like TUMS can be an effective treatment for occasional heartburn. The simple ingredient in TUMS—calcium carbonate—neutralizes stomach acid on contact. TUMS can start providing relief in minutes.

While studies have shown that antacids can be an effective treatment for pregnant women who have heartburn, be sure to talk to your doctor first.⁷ Together, you can come up with a plan that is safe for both you and your baby-to-be.

References

1. “Pregnancy Week by Week: First Trimester Pregnancy: What to Expect.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 14 Apr. 2017, www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy/art-20047208.
2. “Heartburn: Overview.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 17 May 2018, www.mayoclinic.org/diseases-conditions/heartburn/symptoms-causes/syc-20373223.
3. “Definition & Facts for GER & GERD.” National Institute of Diabetes and Digestive and Kidney Diseases, U.S. Department of Health and Human Services, 1 Nov. 2014, www.niddk.nih.gov/health-information/digestive-diseases/acid-reflux-ger-gerd-adults/definition-facts.
4. Griffin, R. Morgan. “Travel Tips: Don’t Vacation With Heartburn.” WebMD, WebMD, 1 Sept. 2006, www.webmd.com/heartburn-gerd/features/heartburn-travel-tips.
5. “Heartburn Overview: Management and Treatment.” Cleveland Clinic, my.clevelandclinic.org/health/diseases/9617-heartburn-overview/management-and-treatment.
6. Richter, J. E. “Review Article: the Management of Heartburn in Pregnancy.” Freshwater Biology, Wiley/Blackwell (10.1111), 14 Oct. 2005, onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2036.2005.02654.x.
7. Vazquez, Juan C. “Heartburn in Pregnancy.” BMJ Clinical Evidence, U.S. National Library of Medicine, 2015, https://misuse.ncbi.nlm.nih.gov/error/abuse.shtml.
8. “Heartburn During Pregnancy: Causes and Treatment.” American Pregnancy Association, July 2015, americanpregnancy.org/pregnancy-health/heartburn-during-pregnancy/.