GI in Pregnancy: GERD and Peptic Ulcer Disease

0:00Welcome to Board Pearls. This is episode two of six of the GI in Pregnancy chapter, in the Special Populations and Acute or Supportive Care module. In this episode we cover GERD and peptic ulcer disease in pregnancy, which test as a stepwise pharmacologic sequence built on local-then-systemic safety logic, with misoprostol prohibited because it contracts the uterus.

0:24The last episode set the physiologic baseline and ran the antiemetic sequence for hyperemesis. This episode takes the other upper-GI symptom that rides on the same physiology.

0:37About two-thirds of pregnant women experience heartburn, and three pregnancy-specific mechanisms drive it together. Progesterone reduces lower esophageal sphincter pressure. The gravid uterus raises intra-abdominal pressure. Gastric emptying slows. So the management starts with lifestyle and mechanical interventions: head-of-bed elevation, smaller meals, avoiding late meals and dietary triggers. Pharmacotherapy is stepped up only when those measures fail.

1:06The first pharmacologic step uses agents that act locally, with minimal systemic absorption. Antacids, alginates, and sucralfate sit at this step. Calcium carbonate is the preferred antacid in pregnancy because it neutralizes acid without aluminum exposure and without sodium bicarbonate. Aluminum-only antacids raise cumulative fetal aluminum concerns and tend to constipate, which compounds pregnancy constipation. Sodium bicarbonate raises maternal alkalosis and sodium retention with edema. Magnesium hydroxide is also acceptable. Alginates form a mechanical raft over the postprandial gastric content that displaces the acid pocket distally. The mechanism is purely physical, with no systemic absorption.

1:52Sucralfate at one gram four times daily is an aluminum hydroxide salt of sulfated sucrose. In gastric acid it releases sulfate anions that bind electrostatically to positively charged proteins on damaged mucosa, coating erosions. Less than five percent is absorbed, so systemic and fetal exposure are negligible. A small randomized trial has shown sucralfate superior to lifestyle measures alone for heartburn and regurgitation in pregnancy. Sucralfate is therefore a reasonable add-on for partial responders, particularly the patient who specifically asks for a non-absorbed option. The practical caveats are that it needs to dose-separate from antacids by about half an hour because it needs acid to polymerize, and it binds other drugs like levothyroxine and fluoroquinolones if co-administered.

2:40H2 receptor antagonists are next when antacids and sucralfate are inadequate. Famotidine is the preferred H2 blocker. It carried the old FDA pregnancy category B and has extensive reassuring data, and it is also preferred during lactation because it is excreted into breast milk in the lowest concentration of the class. Ranitidine is no longer available because of the NDMA contamination withdrawal. Cimetidine is avoided because of its antiandrogenic effects and its cytochrome P450 interactions. So when the boards ask which H2 blocker to use in a pregnant patient, the answer is famotidine, and the reason is class-specific safety rather than potency.

3:23Proton pump inhibitors are the next step when H2 blockade is inadequate. Lansoprazole, pantoprazole, esomeprazole, dexlansoprazole, and rabeprazole were all FDA pregnancy category B. Omeprazole was historically category C because animal studies showed some risk, but in actual clinical use omeprazole has the longest pregnancy track record and is widely used. The category C label is the one historical detail that distinguishes it from the others on the panel. Esomeprazole strontium preparations should not be used during lactation because strontium accumulates in the infant. Potassium-competitive acid blockers like vonoprazan are reserved for refractory cases because pregnancy data are inadequate, and patients are counseled against breastfeeding during use.

4:13Then the contraindication, which is the single most testable rule in this section. Misoprostol is prohibited in pregnancy. It is a prostaglandin E1 analog that produces uterine contractions, and it is in fact used clinically as an abortifacient and to induce labor. The same mechanism that makes it useful for NSAID-related ulcer prophylaxis in non-pregnant patients makes it dangerous in pregnant patients. So when a stem offers misoprostol for either reflux or peptic disease in a pregnant patient, the answer is no, and the reason is mechanism.

4:47Now the why behind the GERD-dominates-PUD pattern, because the boards will test you on it. GERD dominates upper GI symptoms in pregnancy. Peptic ulcer disease is uncommon. The reason is mechanistic. Estrogen drives gastric mucosal hypertrophy and increases mucin secretion, which strengthens the gastric mucosal barrier against acid and pepsin. The same hormonal milieu that loosens the lower esophageal sphincter and produces GERD therefore protects against ulcer formation. So new dyspepsia in a pregnant patient is most often GERD. But new dyspepsia with iron deficiency anemia or melena is not protected by this physiology, and that combination warrants endoscopic evaluation regardless of trimester.

5:29Helicobacter pylori testing and treatment are generally deferred to postpartum unless complicated peptic ulcer disease forces the issue. The reason is that standard quadruple regimens contain bismuth, tetracycline, or other agents that are problematic in pregnancy, and the disease itself is not pregnancy-emergent. Postpartum eradication uses the standard regimens.

5:50Endoscopy in pregnancy is reserved for alarm features: dysphagia, GI bleeding, anemia, weight loss out of proportion to nausea and vomiting of pregnancy, and recurrent vomiting beyond the typical NVP window. The second trimester is the safest timing because organogenesis is complete and the gravid uterus has not yet crowded the operative field. Sedation with midazolam, meperidine, fentanyl, or propofol is acceptable, with benzodiazepines minimized in the first trimester because of cleft lip and palate concerns.

6:23So pull the GERD and PUD threads together. GERD and peptic ulcer disease run the safety-tiered sequence from calcium carbonate and magnesium hydroxide and alginates and sucralfate, through famotidine, to the PPIs, with omeprazole the one historical category-C detail on an otherwise category-B panel, and misoprostol off the table because it contracts the uterus. The pattern that GERD dominates while ulcers are uncommon falls out of estrogen strengthening the gastric mucosal barrier, so new dyspepsia is usually reflux, but dyspepsia with anemia or melena still earns an endoscopy, ideally in the second trimester. The rules are not memorized. They fall out of the physiology and the mechanism, and once those are in place, the stems answer themselves.

7:11In the next episode we move to the liver diseases of pregnancy. It opens on intrahepatic cholestasis of pregnancy with its bile-acid-stratified delivery timing and ursodeoxycholic acid, and runs through the preeclampsia, HELLP, and AFLP spectrum where delivery is the cure, closing on the ruptured hepatic hematoma that is the surgical emergency of the group.

7:31For the full chapter, the practice vignettes, and the topic-tagged question bank, head to board pearls dot com. You'll find the rest of the series on Apple Podcasts, Spotify, or wherever you listen to podcasts. That brings us to the end of episode two of six of chapter thirty five, and I'll see you in the next one.