What causes reflux and heartburn in pregnancy?

What causes reflux and heartburn in pregnancy?

• A. Increased gastric acid secretion
• B. Progesterone decreases muscle tone and motility of LES and stomach; gastric emptying delayed; gravid uterus displaces stomach and LES
• C. Fetal acid production
• D. Increased LES tone

Answer: (B)

During pregnancy, reflux and heartburn arise mainly from hormonal and mechanical changes. Progesterone rises and relaxes smooth muscle throughout the GI tract, including the lower esophageal sphincter, which lowers the barrier to reflux. It also slows gastric emptying, so the stomach remains fuller longer and acid sits in contact with the esophagus longer. As the uterus enlarges, it pushes the stomach and the gastroesophageal junction upward, altering position and further promoting reflux. Increased intra-abdominal pressure from the gravid uterus adds to this effect. Fetal acid production isn’t involved, and increasing LES tone would reduce reflux rather than cause it. So the combination of decreased LES tone, delayed gastric emptying, and uterine displacement best explains reflux and heartburn in pregnancy.

During pregnancy, reflux and heartburn arise mainly from hormonal and mechanical changes. Progesterone rises and relaxes smooth muscle throughout the GI tract, including the lower esophageal sphincter, which lowers the barrier to reflux. It also slows gastric emptying, so the stomach remains fuller longer and acid sits in contact with the esophagus longer. As the uterus enlarges, it pushes the stomach and the gastroesophageal junction upward, altering position and further promoting reflux. Increased intra-abdominal pressure from the gravid uterus adds to this effect. Fetal acid production isn’t involved, and increasing LES tone would reduce reflux rather than cause it. So the combination of decreased LES tone, delayed gastric emptying, and uterine displacement best explains reflux and heartburn in pregnancy.