Yes, constipation during pregnancy is extremely common. A University of Eastern Finland study found that 44% of women experience constipation in the second trimester and 36% in the third. It’s one of the most frequent digestive complaints of pregnancy, driven by hormonal shifts that are a normal part of carrying a baby.
Why Pregnancy Slows Your Digestion
The main culprit is progesterone, a hormone that rises sharply during pregnancy to support the uterus and the developing baby. Progesterone also relaxes smooth muscle throughout your body, including the muscles lining your intestines. Normally, your gut moves food along through rhythmic contractions. Progesterone dials down those contractions by shifting the chemical signaling inside muscle cells toward relaxation and away from contraction. The result is slower transit through the digestive tract, which means your colon absorbs more water from stool, leaving it harder and more difficult to pass.
These hormonal changes become most pronounced in the second and third trimesters, which is why constipation tends to peak during that window. But the hormone shift isn’t the only factor. Your growing uterus physically compresses the intestines, further slowing things down. And if you’re taking prenatal vitamins with iron (most do), that adds another layer.
How Iron Supplements Make It Worse
Iron is essential during pregnancy because your blood volume increases significantly and your baby needs iron for development. But standard iron supplements, particularly ferrous sulfate and ferrous fumarate, are notorious for causing constipation. Your body can only absorb about 18% of consumed iron at a time. The rest travels to the colon, where it oxidizes and creates reactive compounds that slow intestinal movement and harden stool.
If your iron supplement seems to be making constipation significantly worse, ask your provider about gentler forms. Iron bisglycinate (a chelated form bonded to an amino acid) has been shown to cause far fewer digestive side effects while actually being absorbed more efficiently. Heme iron polypeptide, which mimics the iron found naturally in meat, and carbonyl iron, which dissolves slowly in the stomach, are other options that reduce the sudden iron dump into the colon that triggers problems.
What You Can Do About It
The first line of defense is fiber. The recommended intake for pregnant women is about 28 grams per day. Most people fall well short of that. Whole grains, beans, lentils, berries, pears, broccoli, and leafy greens are all good sources. Increasing fiber gradually over a week or two helps avoid the bloating and gas that can come from a sudden jump in intake.
Hydration matters just as much. During pregnancy, your body needs more fluid than usual because it’s building extra blood volume and amniotic fluid. Aim for at least 6 to 8 glasses (roughly 1.6 liters) of water per day, and more if you’re active or in a warm climate. Fiber without enough water can actually make constipation worse, because fiber absorbs fluid to bulk up stool and keep it soft.
Physical activity also helps. Even a 20- to 30-minute walk stimulates the muscles in your intestines and can get things moving. If you were active before pregnancy, continuing a modified routine is one of the simplest ways to support your digestion.
Safe Over-the-Counter Options
When diet and lifestyle changes aren’t enough, several over-the-counter products are generally considered safe during pregnancy. Stool softeners like docusate sodium work by drawing moisture into the stool so it’s easier to pass. They don’t stimulate contractions in the intestines, which is why they’re often recommended as a first step.
Bulk-forming fiber supplements like psyllium are also typically safe because they aren’t absorbed into your bloodstream. They work the same way dietary fiber does, just in concentrated form. Saline laxatives like magnesium hydroxide (Milk of Magnesia) and osmotic options like lactulose are other choices that providers commonly recommend. Stimulant laxatives, which actively trigger intestinal contractions, are considered safe as well but are usually reserved for when milder options haven’t worked. Whichever route you’re considering, it’s worth running it by your provider first, since your specific pregnancy history may affect which option is best for you.
When Constipation Signals Something More Serious
Garden-variety pregnancy constipation is uncomfortable but not dangerous. However, a few symptoms warrant prompt medical attention. Severe or persistent abdominal pain that feels sharp or stabbing is different from the mild cramping of constipation and should be evaluated quickly. Rectal bleeding beyond a small amount from straining, or any vaginal bleeding, also calls for immediate follow-up.
Constipation that lasts more than two weeks despite dietary changes and safe remedies, or constipation that alternates with diarrhea, is worth discussing with your provider. So is constipation accompanied by severe nausea and vomiting where you can’t keep fluids down, since dehydration makes the problem spiral. These situations are uncommon, but recognizing them helps you act quickly if they arise.
What to Expect After Delivery
For many women, constipation doesn’t resolve immediately after birth. The same University of Eastern Finland study found that constipation remains common in the early postpartum period. Hormonal levels take time to normalize, and factors like reduced mobility after a cesarean delivery, pain medications, and the physical recovery process can all keep digestion sluggish for days or weeks. The same strategies that help during pregnancy (fiber, fluids, gentle movement, and stool softeners if needed) apply during recovery as well.