Laxatives in pregnancy

• if lifestyle and dietary measures fail to resolve constipation then laxative treatment may be used:
  • however laxatives should only be taken for short periods on medical advice after considering the benefits and potential risks (1)
  • agents that are not absorbed or are poorly absorbed from the gastrointestinal tract (e.g. bulk-forming agents, faecal softeners, or osmotic agents), are generally preferred for the treatment of constipation in pregnancy
    • Bulk-forming agents
      • are not absorbed or associated with increased risk of malformations (2)
        • are considered safe for long-term use during pregnancy
        • are not always effective and might be associated with unpleasant side effects such as gas, bloating, and cramping
    • Osmotic laxatives
      • lactulose and polyethylene glycol are poorly absorbed systemically
      • use has not been associated with adverse effects; however, individuals might experience side effects such as flatulence and bloating
      • teoretically, prolonged use of osmotic laxatives might lead to electrolyte imbalances (2)
    • Stimulant laxatives
      • absorption of bisacodyl is minimal as it has poor bioavailability
      • there does not appear to be associated with increased risk of malformations associated with senna use
      • senna is not readily absorbed systemically
      • women might experience unpleasant side effects such as abdominal cramps with the use of stimulant laxatives
      • prolonged use might theoretically lead to electrolyte imbalances
    • Stool softeners
      • docusate sodium has not been associated with adverse effects in pregnancy in a number of studies, and it is thus also considered safe to use (2)
      • has been a case report of maternal chronic use of docusate sodium throughout pregnancy, which was associated with symptomatic hypomagnesemia in the neonate (2)
  • senna is acceptable for short periods in moderate doses if other measures fail - however senna should be used cautiously in the third trimester of pregnancy (1)

A systematic review concluded (3):

• is insufficient evidence to comprehensively assess the effectiveness and safety of interventions (pharmacological and non-pharmacological) for treating constipation in pregnancy
• compared with bulk-forming laxatives, stimulant laxatives appear to be more effective in improvement of constipation but are accompanied by an increase in diarrhoea and abdominal discomfort and no difference in women's satisfaction
• fibre supplementation may increase frequency of stools compared with no intervention
• were no data for a comparison of other types of interventions, such as osmotic laxatives, stool softeners, lubricant laxatives and enemas and suppositories.

Consult the respective summary of product characteristics (SPC) before prescribing laxatives during pregnancy.

Reference:

1. MeReC Bulletin (2004); 16(9):21-4.
2. Trottier M, Erebara A, Bozzo P. Treating constipation during pregnancy. Can Fam Physician. 2012 Aug;58(8):836-8. PMID: 22893333; PMCID: PMC3418980
3. Rungsiprakarn P, Laopaiboon M, Sangkomkamhang US, Lumbiganon P, Pratt JJ. Interventions for treating constipation in pregnancy. The Cochrane Database of Systematic Reviews. 2015 Sep(9):CD011448. DOI: 10.1002/14651858.cd011448.pub2. PMID: 26342714; PMCID: PMC8958874.