What are the best medications for constipation during pregnancy?

From the Guidelines

For constipation during pregnancy, the best initial approach is to increase dietary fiber intake to approximately 30g/d and ensure adequate fluid consumption, followed by the use of bulk-forming agents like psyllium husk or methylcellulose if necessary, as these are safe and effective options. According to the most recent guidelines from 2024, constipation in pregnant individuals can result from various factors including hormonal, medication-related, and physiological changes 1. The treatment options recommended include dietary fiber, lactulose, and polyethylene glycol–based laxatives.

Some key points to consider in managing constipation during pregnancy include:

• Increasing dietary fiber intake to the recommended daily amount of approximately 30g/d to promote regular bowel movements and prevent constipation 1.
• Consuming an adequate amount of fluids, particularly water, to help soften stools and ease bowel movements.
• The use of bulk-forming agents, such as psyllium husk or methylcellulose, which are safe to administer in pregnancy due to the lack of systemic absorption 1.
• Osmotic laxatives, such as polyethylene glycol or lactulose, can also be administered safely during pregnancy, but excessive use can cause maternal bloating 1.
• Stimulant laxatives should be avoided because safety data on these medications are conflicting 1.

It's essential to evaluate constipation in pregnant individuals by taking a detailed history regarding the frequency and consistency of bowel movements, presence of pain or bleeding during bowel movements, and severity of symptoms 1. Encouraging pregnant women to avoid straining during bowel movements by providing ample time, using relaxation techniques, and adjusting diet and hydration is also helpful 1. Always consult a healthcare provider before starting any medication during pregnancy.

From the FDA Drug Label

Directions: Adults 12 years & over 1: 1 rounded tablespoon (Tbsp = tablespoon), 3 times daily Ask a doctor before use if you have abdominal pain, nausea or vomiting or experience a sudden change in bowel habits persisting for 2 weeks. Bulk-forming fibers like psyllium husk may affect how well other medicines work. Uses relieves occasional constipation (irregularity) generally produces a bowel movement in 12 -72 hours. Ask a doctor before use if you have a sudden change in bowel habits that persists over a period of two weeks abdominal pain, nausea or vomiting

Psyllium (PO) and methylcellulose (PO) are two medications that can be used to relieve constipation.

• It is recommended to consult a doctor before taking any medication during pregnancy, especially if you have abdominal pain, nausea, or vomiting.
• Psyllium (PO) and methylcellulose (PO) can be used to relieve occasional constipation, but it is essential to follow the instructions and take the medication with at least 8 oz of liquid to avoid choking.
• If you experience rectal bleeding or constipation lasts more than 7 days, you should stop use and ask a doctor as these may be signs of a serious condition 2 3.

From the Research

Medications for Constipation during Pregnancy

The following medications are considered for constipation during pregnancy:

• Fiber supplements: Evidence supports treatment with fiber supplements 4, 5
• Senna: Evidence supports treatment with senna 4
• Osmotic laxatives: May be beneficial for some patients 4, 6
• Stimulant laxatives: May be used in the short term or occasionally to avoid dehydration or electrolyte imbalances in pregnant women 6, 5
• Macrogol (polyethylene glycol, PEG): Shows some advantages, such as faster onset of bowel action and fewer flatulences 7
• Lactulose: May be used as a first-line therapy in treating chronic constipation during pregnancy 7
• Bisacodyl and sodium picosulfate: May be used as a second-line treatment in the second and third trimester 7

Key Considerations

• Most laxatives carry a pregnancy category B or C classification 4
• The use of a pharmacologic agent for treatment of constipation during pregnancy must be weighed against possible adverse effects 4
• Short-term use of osmotic or stimulant laxatives is generally reserved for patients who fail to respond to dietary changes or bulking agents 4, 6
• Stimulant laxatives appear to be more effective in improvement of constipation, but are accompanied by an increase in diarrhoea and abdominal discomfort 5