Lifestyle and Complementary Medicine for Common Gastrointestinal Disorders in Pregnancy

Abstract

Gastrointestinal disorders including nausea, vomiting, heartburn, and constipation are common in pregnancy. While safe and effective pharmacotherapy exists to ameliorate the symptoms of these conditions, many women prefer a more natural approach through lifestyle modifications or complementary medicine. Evidence concerning some of the most commonly used lifestyle or complementary medicine interventions is discussed, as well as their associated adverse effects and safety in pregnancy.

“While safe and effective pharmacotherapy exists to ameliorate the symptoms of [gastrointestinal disorders], many women prefer a more natural approach through lifestyle modifications or complementary medicine.”

Gastrointestinal (GI) disorders including nausea, vomiting, heartburn, and constipation are common in pregnancy. Many of these conditions are thought to arise from motility disturbances caused by increased levels of circulating progesterone. While safe and effective pharmacotherapy exists to ameliorate the symptoms of these conditions, many women prefer a more natural approach through lifestyle modifications or complementary medicine.

Up to 78% of women use complementary or alternative medicine during pregnancy. ¹ The most common modalities reported include vitamin and mineral supplements, herbal medicine, massage, relaxation, and aroma therapy. ² Instead of consulting their health care professional, many expectant mothers rely on family and friends for information regarding these lifestyle and natural therapies. ² Although well intentioned, friends and family may not be well informed on the safe and effective use of lifestyle and complementary medicine in pregnancy, so it is important that health care providers ask patients about their use and make sound recommendations based on evidence.

The purpose of this article is to provide a summary of the evidence concerning some of the most commonly used lifestyle and complementary medicine interventions to treat nausea, vomiting, heartburn, and constipation in pregnancy.

Nausea and Vomiting

One of the most common and unpleasant conditions of pregnancy is nausea and vomiting, colloquially referred to as “morning sickness.” It is often the first symptom of pregnancy and affects as many as 80% of women. ³ Nausea is most common during the first trimester of pregnancy and often abates after 3 to 4 months but may continue beyond this time in up to 20% of women. ⁴ Several factors contribute to these symptoms, including pregnancy-associated disturbances in gastric motility (secondary to increased progesterone secretion); elevations of human chorionic gonadotropin; alterations in taste, smell, and the vestibular system; and other psychological aspects.

Several dietary measures have been proposed to reduce the frequency and severity of pregnancy-associated nausea and vomiting. These include eating frequent, small meals (every 2-3 hours) and avoiding smells and food textures that cause nausea. Solid food should be bland tasting and comprised of mostly carbohydrates and little fat. These interventions have been recommended for years but are based on clinical experience and physiological conjecture rather than evidence-based medicine. ⁵

Acupressure is a noninvasive form of acupuncture and has been proposed to treat symptoms of nausea and vomiting. The P6 or Neiguan point is the most common acupressure point used for nausea, located 3 fingerbreadths above the wrist on the volar surface. ⁶ Constant pressure can be applied at this point by the finger or through various commercially available wristbands (ie, SeaBand). Although the literature is conflicting regarding the efficacy of this modality, a 2010 Cochrane review found no statistically significant effect from acupressure compared with placebo in the 4 randomized controlled trials available. ⁷ One study that compared P6 acupressure to vitamin B₆ supplementation found no statistically significant difference between groups for improvement of nausea. ⁷ Side effects of acupressure were mild and included irritation around the wristband site.

Vitamin B₆, or pyridoxine, had favorable results when used as a supplement for pregnancy-related nausea and vomiting in 2 placebo-controlled studies. ⁷ One randomized controlled trial demonstrated that pyridoxine, at a dose of 25 mg every 8 hours, was more effective than placebo for controlling nausea and vomiting in pregnant women. ⁸ In pharmacological doses, vitamin B₆ has not been found to be teratogenic and is rated FDA pregnancy category A. ⁹

The use of ginger in the management of pregnancy-related nausea and vomiting is a well-known therapy in popular culture and commonly recommended despite conflicting evidence. A recent review found 4 randomized controlled trials comparing ginger with placebo or vitamin B₆ for pregnancy-related nausea and vomiting. ³ Daily doses of ginger ranged from 500 to 1050 mg. Ginger was found to be as effective as vitamin B₆ in reducing nausea and vomiting and superior to placebo in reducing nausea, decreasing the intensity of nausea, and decreasing the frequency of vomiting.^3,7 The most common side effects of ginger therapy included burning sensation and belching. ³ To date, there have been no published reports of fetal anomalies associated with ginger supplementation at doses less than 4 g daily. ³

Constipation

Constipation is also a frequently experienced GI symptom of pregnancy, affecting up to 40% of women. ¹⁰ Many women who experience constipation prior to pregnancy have worsening symptoms during pregnancy. Patients can also develop constipation for the first time during pregnancy. The cause of constipation in pregnancy is multifactorial and may include diet changes, iron supplementation, and decreased physical activity. Other potential causes include small and large bowel hypomotility secondary to increased progesterone secretion, excessively dry stool from increased colonic water absorption, and mechanical impedance secondary to movements in the uterus and intestinal tract during late pregnancy.

First-line therapy for constipation in pregnancy includes increasing fluids, dietary fiber, and physical activity. Although this information is widely disseminated among patients, the evidence substantiating these treatments is lacking. One randomized controlled trial compared increased dietary fiber versus no additional fiber for 2 weeks in pregnant patients. ¹¹ The fiber was provided in the form of corn-based biscuits or wheat bran (approximately 10 g of fiber added daily). Compared with the women who received no additional fiber, the women with increased dietary fiber had a significantly increased frequency of bowel movements. This study, although small in sample size (40 women in the third trimester of pregnancy), supports the recommendation for increased fiber intake in pregnancy, especially in women who may have deficient fiber intake. There are no randomized controlled trials assessing the efficacy of increased fluid intake or increased physical activity to treat constipation in the pregnant population. ¹¹ In the general population, these recommendations are largely unsubstantiated as well. ¹² The literature supporting these interventions involves populations lacking or deficient in fiber, fluid, or physical activity. Despite lack of clear evidence, increasing fluid intake, dietary fiber, and physical activity should still be recommended for management of constipation in pregnancy. The interventions are low in cost, are readily available, and confer several other beneficial effects during pregnancy.

Bulking agents like psyllium (commercially available as Metamucil, Citrucel, etc) are not systemically absorbed or associated with increased risk of malformations during pregnancy. ¹³ No randomized controlled trials exist comparing psyllium with placebo in treating constipation in pregnancy, but its use is supported by at least 3 randomized controlled trials demonstrating benefit over placebo in improving stool consistency and decreasing colonic transit time in the general population.^12,14 These agents take several days to begin working but can be used for long periods of time to manage uncomplicated constipation. Side effects include gas, bloating, and cramping, which can be reduced with adequate fluid intake.

Heartburn

Heartburn affects 40% to 80% of women at some time during pregnancy and is associated with decreased quality of life. ¹⁵ The cause for heartburn in pregnancy, like nausea and constipation, is multifactorial. Increased progesterone relaxes smooth muscle, which decreases gastric tone and motility and decreases lower esophageal sphincter pressure. ¹¹ Additionally, mechanical changes including pressure from the growing uterus on stomach contents may play a role.

Lifestyle modifications to reduce heartburn in pregnancy include eating frequent small meals, avoiding foods that induce reflux (spicy or greasy foods; acidic foods including tomatoes, citrus fruits, and carbonated drinks), avoiding lying down within 3 hours of eating, elevating the head of the bed while sleeping, and avoiding caffeine intake. While consensus exists that these interventions be recommended as first-line therapy for heartburn in pregnancy, evidence is lacking. ¹⁶

There are no randomized controlled trials assessing the efficacy of raising the head of the bed, reducing caffeine intake, reducing the intake of fatty foods, or reducing the size and frequency of meals for heartburn in pregnant women. ¹¹ In the general population, there is no randomized controlled trial evidence to support dietary changes and caffeine avoidance for heartburn, and there is incomplete evidence to support avoiding late-night meals. ¹⁷ There is some evidence to support the recommendation of raising the head of the bed or sleeping on a wedge to prevent heartburn in the general population. ¹⁷ This intervention has been shown to significantly reduce and shorten reflux episodes and decrease esophageal acid exposure (significant only in those who slept on a wedge) compared with sleeping flat. ¹⁷

Conclusions

More research is necessary to support dietary modifications (eating smaller, more frequent meals, consuming bland, carbohydrate-dominant solids) to reduce nausea and vomiting in pregnancy. These interventions are based on clinical experience and physiological conjecture. Because there is little risk associated with their implementation, they are reasonable recommendations for pregnant women. The data regarding acupressure therapy are conflicting and incomplete, but it may be another viable alternative. Evidence indicates that vitamin B₆ and ginger are safe and effective treatments for pregnancy-associated nausea and vomiting at pharmacological doses (ginger 1000 mg daily, vitamin B₆ 25 mg every 8 hours).

First-line therapy for constipation in pregnancy includes increasing fluids, dietary fiber, and physical activity, despite lack of evidence. In the general population, these recommendations have been supported in patients deficient in fluid, fiber, or exercise. These interventions carry little risk and have other beneficial effects in pregnancy, and thus they are reasonable recommendations for constipation in pregnancy. If lifestyle alone does not manage the constipation, bulk-forming agents such as psyllium may be safely used in pregnancy.

Although there is physiological evidence that certain foods may adversely affect symptoms of heartburn, there is little evidence that avoidance of these agents improves gastroesophageal reflux, even in the general population. These interventions carry little risk and are therefore reasonable options for pregnant patients. Raising the head of the bed at night or sleeping on a wedge pillow has favorable evidence in treating heartburn in the general population and may also be applicable for pregnant women; further research is necessary to substantiate this.