Constipation during pregnancy

By trimester

Weeks 1–13

1st trimester

Constipation often starts early, as rising progesterone slows digestion and prenatal iron adds to the effect. Focus on hydration, aim for 8 to 12 cups of fluid a day, soluble fiber like pears, apples, and prunes, and daily movement.

Weeks 14–27

2nd trimester

The same approach still applies. When diet and movement aren't quite enough, a stool softener like docusate is often the next step.

Weeks 28–birth

3rd trimester

Growing uterine pressure adds to the earlier causes. Osmotic laxatives like polyethylene glycol or milk of magnesia are common provider-directed options, while stimulant laxatives are generally used less.

What does the evidence show for constipation?

• Constipation is one of the most common digestive complaints in pregnancy, affecting a large share of pregnant women. 1
• Docusate, a common stool softener, is widely used and generally considered fine during pregnancy at standard over-the-counter doses. 2
• Osmotic laxatives like polyethylene glycol are commonly used during pregnancy, while stimulant laxatives are typically saved for short-term, provider-directed use. 3
• Getting enough fluids and fiber is the first-line approach for pregnancy-related constipation. 4
• Magnesium supplements have a laxative effect at doses of 350 mg a day or more, so it's worth using them with provider oversight if you're relying on magnesium for stool support. 5
• Constipation alongside rectal bleeding, blood in the stool, constant abdominal pain, inability to pass gas, vomiting, fever, lower back pain, or losing weight without trying are reasons to see a doctor right away rather than continuing home management. 6

When should I call my provider about constipation?

Constipation on its own is common, but a few things alongside it are not: constant belly pain instead of the usual crampy fullness, an inability to pass gas at all, vomiting, fever, or losing weight without trying all point past ordinary pregnancy constipation and are worth a same-day call. Rectal bleeding or blood in the stool also belongs in that same-day category rather than something to track for a few more days. If nothing has moved in more than a week despite fiber, fluids, and movement, check in with your provider rather than continuing to escalate home measures alone. Whatever the pattern, any symptom that feels beyond your usual range is a reason to call: obstetric teams expect these questions and would rather hear early than late.