Contributor: Dr. A. Jain

Introduction

Gastroesophageal reflux disease (GERD) is a condition whereby acid juices and other contents of the stomach reflux into the esophagus (swallowing tube). Heartburn is a common symptom of GERD and occurs often in the adult population. Symptoms of heartburn include a burning sensation behind the breastbone and can be exacerbated when bending over or lying down. Approximately 10% of the non-pregnant adult population has regular symptoms of heartburn and approximately 1/3 will have symptoms of GERD at some point in their lives. Although the precise incidence of heartburn is difficult to determine, it is estimated that greater than 25% of pregnant women experience daily symptoms of heartburn and at least 50% will experience heartburn at some point during their pregnancy.

A large study including 607 women revealed that the frequency and severity of heartburn increased throughout pregnancy:

Risk factors that increased the likelihood of heartburn during pregnancy include increased gestational age, and the presence of heartburn prior to pregnancy. Neither the pre-pregnancy body mass index (a height to weight ratio) nor weight gain during pregnancy were found to be predictors of frequency or severity of heartburn symptoms.

Cause of GERD

Multiple factors have been implicated in causing GERD: an abnormal or defective anti-reflux barrier, impaired ability to clear food from the esophagus, delayed emptying of the stomach and the quantity of acid secretion.

The lower esophageal sphincter (LES), is the band of muscle tissue at the lower end of the esophagus which is responsible for opening (to allow food to pass) and closing to maintain a pressure barrier against contents from the stomach and prevent them from coming back up into the esophagus. If the LES weakens and loses its tone (i.e. decreased LES pressure), then it cannot close up completely after food empties into the stomach. As a result, acid from the stomach refluxes into the esophagus. Dietary substances, drugs, and nervous system factors can weaken it and impair its function.

During pregnancy, women can also have increased abdominal pressure as a result of an enlarged uterus. This increased abdominal pressure may be an additional mechanism that contributes to acid reflux and to decreased LES pressure.

Research data

Lower esophageal sphincter pressure has been assessed in many studies. In one study of 39 pregnant women, 20 with and 19 without heartburn, the LES pressure tended to be lower in symptomatic patients. In addition, the LES pressure progressively declined throughout pregnancy and subsequently normalized postpartum. Another study that measured LES pressure at the end of each trimester and also 4 weeks postpartum had observed similar findings. This phenomenon is a result of the effect of the hormones, estrogen and progesterone, on the LES pressure during pregnancy.

A study examining the time it takes food to go from mouth to the cecum (first part of the large intestine) found this "transit time" was delayed in pregnant women in their third trimester, compared to the transit time when measured 4 weeks postpartum.

Diagnosis

The classic presentation of a burning sensation behind the breastbone occurring after meals, and exacerbated when bending over or lying down, essentially makes the diagnosis of GERD.
If pregnant women's symptoms are unmanageable with standard medical therapy or if warning signs are present (such as weight loss, vomiting blood, difficulty swallowing), then an upper endoscopy examination may be warranted. Barium x-rays must be avoided in pregnancy given the risk of the x-rays to fetal development. Endoscopy has been shown to be safe in pregnant women with no increased risk to either mother or baby.

Treatment

More often than not, pregnant women have relatively mild to moderate symptoms of GERD and can usually be managed with lifestyle and dietary modifications and non-prescription remedies.

Lifestyle modifications
- Elevation of head of bed (can use a wedge)
- Sleeping on your left side
- Decrease/quit smoking
- Avoid potentially harmful medications (NSAIDS, aspirin)

Dietary modifications
- Less fat, more protein
- Avoid irritants (citrus juices, coffee, cola, teas, alcohol, tomato products)
- Avoid recumbency for 2-3 hours after meal
- Avoid chocolate

Non-prescription remedies
- Antacids
- Alginic acid

In pregnant patients with moderate to severe symptoms of GERD, other agents are available. Sulcrafate is safe in pregnancy with minimal or no systemic absorption. Sulcrafate has been shown in a randomized study of 66 pregnant women, to be superior to lifestyle and dietary modifications in relieving symptoms of heartburn (90% vs 30%) and reflux (83% vs 27%).

Two other class of medications that have been used widely for the treatment of symptoms of GERD, histamine-receptor antagonists (H2RAs or H2 blockers) and proton-pump inhibitors (PPIs), have not been adequately studied in the pregnant population. There have been no reports of fetal harm with the H2RAs: cimetidine, ranitidine or famotidine. These agents should only be used if absolutely necessary. The H2RA, nizatidine, has been shown in animal studies to cause miscarriage, fewer live births, and low birth weight and therefore, nizatidine should be avoided in pregnancy. The data regarding the safe use of PPIs (ie. omeprazole, lansoprazole, pantoprazole, rabeprazole) in pregnancy is limited. There have been several cases of the use of omeprazole in pregnant women without complication. The safest approach is to limit the use of PPIs in pregnancy, although these drugs are likely to be safe.

Past reports

None

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