Dealing with Gastro-oesophageal Reflux Disease During Pregnancy
Dealing with Gastro-oesophageal Reflux Disease During Pregnancy
European Gastroenterology Review 2005 - September 2005
Published: October 2005
Published: October 2005
A high proportion of women report symptoms of gastro-oesophageal reflux disease (GORD) during pregnancy. For most women, heartburn is a new symptom that is most troublesome in the third trimester and resolves with delivery. Diminished basal lower oesophageal sphincter (LOS) pressure, impaired oesophageal peristalsis and raised intraabdominal pressure could contribute, but knowledge of the underlying mechanisms is incomplete. Although the choice of therapy is influenced by available safety data in pregnancy, complications of GORD are unusual due to the limited duration of this form of the disease.
Prevalence
Estimates of the prevalence of reflux symptoms during pregnancy vary from 30% to 80% of women, but up to 70% may experience daily heartburn during the third trimester.1 The severity of symptoms increases progressively throughout pregnancy, but they typically resolve with delivery.2
Risk factors for GORD in pregnancy include multiparity and a history of heartburn before pregnancy or during a previous pregnancy, but the prevalence may decrease with advancing maternal age.1
Pathogenesis
Manometry studies demonstrate that the basal LOS pressure decreases progressively throughout pregnancy,3,4 and the LOS also becomes less responsive to smooth muscle stimulants.5 Ex vivo animal data implicate oestrogen and progesterone in this impairment of smooth muscle function.6 Transient relaxations of the LOS are the most prevalent mechanisms of acid reflux in the general population of GORD sufferers,7 but whether these are increased during pregnancy has not been studied. Hiatus hernia is also a predisposing factor for GORD,8 but its prevalence in pregnancy is unknown.
Increased intra-abdominal pressure from the gravid uterus would not in itself appear to be sufficient to provoke GORD, because other conditions associated with increased intra-abdominal pressure, such as ascites, are accompanied by a compensatory increase in LOS pressure.9 However, symptomatic pregnant women do not appear to have the same compensatory rise in LOS pressure in response to abdominal compression when compared with asymptomatic controls.10
Both the amplitude and propagation velocity of peristalsis in the oesophageal body were diminished in a small study in pregnant women,11 suggesting the potential for impaired acid clearance. Nevertheless, fluctuations of progesterone throughout the normal menstrual cycle are reported not to influence oesophageal peristalsis or acid exposure.12
Delayed gastric emptying contributes to the pathogenesis of GORD in a proportion of the general population. However, gastric emptying of solids does not appear to be delayed during at least the first half of pregnancy.13
