From the Guidelines
During pregnancy, the lower esophageal sphincter (LES) tone decreases due to elevated progesterone levels, leading to higher rates of gastroesophageal reflux disease (GERD) in pregnant women. This decrease in LES tone is attributed to the relaxing effect of progesterone on smooth muscle throughout the body, including the LES 1. The frequency of heartburn, nausea, and vomiting during pregnancy ranges from 30%–90%, with nausea and vomiting of pregnancy (NVP) usually beginning at 4–6 weeks, peaking at 8–12 weeks, and subsiding by week 20 1.
Management of Symptoms
Management of these symptoms includes:
- Diet and lifestyle modification as the initial steps
- Reducing spicy, fatty, acidic, and fried foods to help reduce heartburn
- Eating small, frequent, and bland meals, such as the BRAT (bananas, rice, applesauce, and toast) diet, and high-protein and low-fat meals to help with NVP
- Identifying and avoiding specific triggers, such as certain foods with strong odors or activities
- Considering therapeutic options like ginger (a 250-mg capsule 4 times daily) and vitamin B6 (pyridoxine, 10–25 mg every 8 hours) for persistent or severe symptoms 1
Pharmacologic Therapies
If symptoms are persistent or severe, pharmacologic therapies may be considered, including:
- H1-receptor antagonists, such as doxylamine, promethazine, and dimenhydrinate, as safe first-line antiemetic therapies
- Doxylamine and pyridoxine combinations (10 mg/10 mg and 20 mg/20 mg) as safe and well-tolerated options 1
- Early intervention and treatment of NVP to help prevent progression to hyperemesis gravidarum (HG) 1
Outcome
These physiological changes typically resolve after delivery as hormone levels normalize and abdominal pressure decreases, with most women experiencing complete resolution of symptoms postpartum. The primary goal is to manage symptoms effectively while minimizing risks to the mother and fetus, prioritizing morbidity, mortality, and quality of life as outcomes.
From the Research
Lower Esophageal Sphincter Tone in Pregnancy
- The tone of the lower esophageal sphincter (LES) is affected during pregnancy, with studies suggesting a decrease in LES pressure due to female sex hormones, especially progesterone 2.
- This decrease in LES pressure can lead to gastroesophageal reflux disease (GERD) symptoms, such as heartburn, which are common during pregnancy, affecting approximately two thirds of pregnant patients 2.
- The prevalence of GERD increases during pregnancy, with a study finding a prevalence of 45.5% in pregnant women, and symptoms being more frequent in the second and third trimesters 3.
Factors Affecting Lower Esophageal Sphincter Tone
- Hormonal changes during pregnancy, particularly the increase in estrogen and progesterone levels, can affect LES function, with studies showing reduced LES pressure responses to hormonal, pharmacological, and physiological stimulation 4.
- Mechanical factors, such as increased intra-abdominal pressure due to the enlarged gravid uterus, can also contribute to decreased LES tone 3.
- Dietary factors, such as non-vegetarianism and frequent consumption of aerated beverages, can increase the risk of reflux in pregnancy 3.
Management and Treatment
- Symptomatic GERD during pregnancy can be managed with a step-up algorithm, starting with lifestyle modifications and dietary changes, followed by antacids or sucralfate, and then H2RAs or proton-pump inhibitors if symptoms persist 2.
- Domperidone, a new antiemetic, has been shown to increase resting LES tone, and may be a valuable premedicant in some patients to decrease the chance of gastro-esophageal reflux 5.