GI in Pregnancy: GI in Pregnancy: Reflux and Gallstones

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. This episode is the upper gastrointestinal, GI, tract and the gallbladder in pregnancy, followed in one woman who has heartburn and then gallstones. Her heartburn shows why pregnancy causes reflux but protects against ulcers, how treatment steps up from lifestyle changes through antacids to acid blockers, which antacids are avoided, why proton pump inhibitors are safe, which drug must never be given, and when an endoscopy is needed. Her gallstones show when biliary colic is watched and when the gallbladder comes out, when an endoscopic retrograde cholangiopancreatography, ERCP, is justified and how it's made safe, and which antibiotics are off the table.

0:49Here's the patient. A thirty-three-year-old woman is eighteen weeks pregnant with burning heartburn most evenings and some regurgitation at night. She has no dysphagia, weight loss, or bleeding, and her hemoglobin is normal for pregnancy. She's been taking sodium bicarbonate from her kitchen cupboard and an over-the-counter antacid that contains aluminum. She usually eats a large dinner late in the evening.

1:12She has gastroesophageal reflux of pregnancy, typical heartburn and regurgitation without alarm features. About two-thirds of pregnant women have heartburn, from three changes acting together: progesterone lowers the pressure of the lower esophageal sphincter, the enlarging uterus raises intra-abdominal pressure, and gastric emptying slows. Those mechanisms set the order of treatment. Lifestyle and mechanical measures come first: raising the head of the bed, eating smaller meals, avoiding late meals, and avoiding dietary triggers. Drugs are added only when those aren't enough. Raising the head of her bed and eating earlier and smaller meals helps her a little, but not enough.

1:52Her next step is a local agent, and both of the products she's been using are the ones to avoid. Antacids, alginates, and sucralfate come first among drugs, because they act locally without meaningful absorption. Calcium carbonate is the preferred antacid, because it neutralizes acid without aluminum, which raises concern about cumulative fetal exposure, and without sodium bicarbonate, which risks maternal alkalosis and sodium retention with edema. Magnesium hydroxide is also acceptable. Alginates form a mechanical raft over the meal that pushes the acid pocket down, with no absorption at all.

2:29Sucralfate, one gram four times daily, releases sulfate anions in acid that bind to damaged mucosa and coat erosions, and under five percent is absorbed, so fetal exposure is negligible. A small randomized trial showed it beat lifestyle measures alone for heartburn and regurgitation in pregnancy. So she stops her bicarbonate and her aluminum antacid and switches to calcium carbonate, with an alginate after meals.

2:55If local agents aren't enough, the next step is an H2 receptor antagonist. Famotidine is preferred, on the available human data and during breastfeeding, because it reaches breast milk in the lowest concentration of its class. Ranitidine is no longer available, after its withdrawal for N-nitrosodimethylamine contamination. Two weeks later she's still waking with heartburn, so she starts famotidine.

3:21If famotidine isn't enough, a proton pump inhibitor, PPI, follows, and all PPIs are considered compatible with pregnancy on current human data. Omeprazole once carried a less favorable Food and Drug Administration, FDA, letter category than the other PPIs, based on animal data, even though it has the longest human pregnancy record, so she's reassured that its old label doesn't mean it's less safe. Esomeprazole strontium isn't used during breastfeeding, because strontium accumulates in the infant. Potassium-competitive acid blockers such as vonoprazan are reserved for refractory cases, because pregnancy data are inadequate, and breastfeeding is advised against while they're used.

4:02One drug used with acid suppression outside pregnancy is never given to her. Misoprostol is a prostaglandin E1 analog that causes uterine contractions and is used clinically as an abortifacient. The same action that makes it useful for preventing ulcers from nonsteroidal anti-inflammatory drugs, NSAIDs, outside pregnancy makes it dangerous in pregnancy. If a plan arose to pair it with an NSAID for back pain during her pregnancy, both would be stopped.

4:32The hormones that cause her reflux also protect her from ulcers. Estrogen thickens the gastric mucosa and increases mucin secretion, strengthening the barrier against acid and pepsin, so peptic ulcer disease is uncommon in pregnancy while reflux dominates. New dyspepsia in pregnancy is most often reflux. But dyspepsia with iron deficiency anemia or melena isn't covered by that protection and warrants endoscopy.

4:57Helicobacter pylori testing and treatment are generally deferred until after delivery, unless complicated ulcer disease forces the issue, because the standard quadruple regimens contain bismuth, tetracycline, or other agents that are problematic in pregnancy, and the infection isn't urgent. After delivery, eradication uses the standard regimens from chapter six.

5:18Her heartburn doesn't need an endoscopy, because she has no alarm features. Endoscopy in pregnancy is reserved for dysphagia, GI bleeding, anemia, weight loss out of proportion to nausea of pregnancy, and vomiting that continues beyond the usual window for nausea of pregnancy. When it's needed, the second trimester is safest, because organogenesis is complete and the uterus doesn't yet crowd the field. Midazolam, meperidine, fentanyl, or propofol are acceptable for sedation, with benzodiazepines minimized in the first trimester because of the cleft lip and palate concern from chapter twenty-eight. Melena with a falling hemoglobin would bring her to endoscopy, and at eighteen weeks she's already in the safest window.

6:01Then her gallbladder causes trouble. At twenty-two weeks she has a first three-hour episode of right upper quadrant pain after a fatty meal. Ultrasound shows gallstones without wall thickening and a normal bile duct, and her liver tests and lipase are normal.

6:17She has uncomplicated biliary colic, a first mild episode. Pregnancy promotes gallstones, which develop in about one in ten pregnancies, as episode one explains. Symptomatic colic occurs in about one in a thousand pregnancies, and pancreatitis or cholecystitis in about one in ten thousand. A first mild episode is managed conservatively, with diet modification and pain control, because most stones don't progress and surgery is better deferred when it can be.

6:46What happens next decides whether she has surgery. Recurrent colic, complicated gallstone disease, or gallstone pancreatitis is the indication for laparoscopic cholecystectomy, in the second trimester, which carries a lower miscarriage risk than first-trimester surgery and easier exposure than third-trimester surgery. At twenty-five weeks, after two more attacks, her colic is recurrent, so she has a laparoscopic cholecystectomy while she's still in the second trimester, rather than facing more attacks and a later operation in a crowded field. Waiting for the stones to disappear after delivery wouldn't work: sludge usually resolves after delivery, but stones found in pregnancy persist in about eighty percent.

7:26If her stones had caused a duct problem, ERCP would be justified only for cholangitis, persistent biliary obstruction, or a large stone with refractory symptoms. Fever, jaundice, and a dilated duct would mean ERCP, done with every protection. An experienced endoscopist uses limited, pulsed fluoroscopy and lead shielding over the abdomen, with a fetal dose target under one millisievert, against a cumulative teratogenic threshold of fifty milligray, to which the fetus is most sensitive in the first trimester. Where it's feasible, wire-guided cannulation without fluoroscopy reduces radiation further. Propofol is the preferred sedation, and magnetic resonance cholangiopancreatography, MRCP, without gadolinium is the preferred imaging beforehand when the anatomy needs defining.

8:18Her antibiotics, if she had cholangitis or gallstone pancreatitis, would come from a narrower list. The choices are a beta-lactam with a beta-lactamase inhibitor, ampicillin-sulbactam or piperacillin-tazobactam, or a cephalosporin plus metronidazole. Fluoroquinolones are avoided because of a cartilage signal in animal studies, and tetracyclines because they bind fetal teeth and bone, causing yellow-brown staining and impaired enamel. So cholangitis in her would be treated with piperacillin-tazobactam, not ciprofloxacin or doxycycline.

8:52Here are the traps the boards set in these patients. Recommending sodium bicarbonate or aluminum antacids in pregnancy. Skipping lifestyle measures and local agents. Avoiding PPIs because of an old letter category. Giving misoprostol. Treating H. pylori during pregnancy without a complication that demands it. Scoping typical heartburn without alarm features, or missing melena or anemia as a reason to scope. Operating for a first mild episode of colic, or delaying cholecystectomy for recurrent colic beyond the second trimester. Expecting stones to disappear after delivery. And giving fluoroquinolones or tetracyclines for biliary infection.

9:32So, start to finish. Heartburn of pregnancy is treated with lifestyle changes first, then calcium carbonate, alginates, or sucralfate, then famotidine, then a PPI, and all of them are acceptable in pregnancy. Misoprostol is never given. Peptic ulcer is uncommon in pregnancy, so H. pylori treatment waits until after delivery, and endoscopy is done only for alarm features, ideally in the second trimester.

9:59A first mild episode of biliary colic is managed conservatively, and recurrent colic, cholecystitis, or gallstone pancreatitis leads to laparoscopic cholecystectomy in the second trimester. ERCP is reserved for cholangitis or persistent obstruction, with minimal fluoroscopy and shielding, and biliary infection is treated with beta-lactams, avoiding fluoroquinolones and tetracyclines.

10:23Episode three is the liver diseases unique to pregnancy: intrahepatic cholestasis, the syndrome of hemolysis, elevated liver enzymes, and low platelets, HELLP, and acute fatty liver.

10:35For 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.