Heartburn in Pregnancy

What Pregnancy Heartburn Is

The lower esophageal sphincter is the muscle that normally keeps stomach contents from moving back up into the esophagus. Research on pregnancy heartburn describes progesterone, along with other female sex hormones, as relaxing that muscle and reducing gastric motility, which lets acid reflux upward more easily.^[2][3] Direct measurements found that while resting sphincter pressure in early pregnancy stayed close to normal, its pressure response to hormonal and physiological stimuli was measurably blunted, evidence for a hormonal effect on the sphincter that can be present well before the uterus has grown much at all.^[3]

As pregnancy progresses, a second factor layers on top. The growing uterus raises pressure inside the abdomen and pushes on the stomach, and it also displaces the lower esophageal sphincter itself into the chest cavity, an area of negative pressure that makes it easier for stomach contents to move upward.^[2] That combination is why heartburn is described in the research as most frequent and most pronounced later in pregnancy, even though the hormonal piece is already at work from early on.^[4]

How It's Logged

There's no test that measures heartburn directly. It's a self-reported symptom, logged on the days it happens and how strong it felt. Tracked across a pregnancy, a dated log shows whether heartburn is following the trimester-by-trimester pattern research describes, or whether it's showing up on its own schedule, alongside other digestive changes.

Why People Track Heartburn

Heartburn is one of several digestive symptoms that shift across pregnancy, alongside nausea, bloating, and changes in bowel habits. Logging it separately from those other symptoms, with a date and a rough sense of severity, makes it possible to see whether heartburn is trending with the trimester the way research describes, or clustering around specific meals or times of day instead.

Our guide on cycle-related digestive changes covers the broader category of gut symptoms this site tracks, from bloating to bowel changes, for anyone looking at digestive symptoms outside of pregnancy as well.

How Go Go Gaia Tracks Heartburn

Go Go Gaia logs heartburn with a 1-click entry in pregnancy mode, rated by severity, no typing required. Each entry is charted against your week of pregnancy and everything else you're tracking, so you can see how heartburn is trending as your pregnancy progresses.

What the Research Shows

Reported incidence of heartburn in pregnancy ranges from 17% to 45% across studies.^[1] One frequently cited study of pregnant women found a clear trimester pattern: 22% reported heartburn in the first trimester, 39% in the second, and 72% in the third.^[4]

Research on the condition describes symptoms as usually easing after birth for people without a prior history of reflux.^[5]

Related Terms

Frequently Asked Questions

Educational information based on published sources. Not medical advice. For personal concerns, please consult your doctor.

Why does heartburn get worse in pregnancy?

Two mechanisms are described in the research. Rising progesterone relaxes the lower esophageal sphincter, the muscle that normally keeps stomach acid from moving into the esophagus, and reduces stomach motility.^[2] Later in pregnancy, the growing uterus adds mechanical pressure on the stomach and pushes the sphincter into an area of negative pressure in the chest, both of which make reflux more likely.^[2]

How common is heartburn during pregnancy?

Research puts the overall incidence at 17% to 45% of pregnancies, and one study found it rising sharply by trimester: 22% in the first trimester, 39% in the second, and 72% in the third.^[1][4]

Does pregnancy heartburn go away after delivery?

For people without a prior history of reflux, symptoms usually ease after delivery, according to research on the condition.^[5]