What laxative is safe during pregnancy

Ah, pregnancy — so many symptoms, so few pregnancy-approved medications. The good news is when it comes to easing constipation, there are some meds that are generally considered safe to use when you’re expecting — including milk of magnesia, a popular over-the-counter laxative.

But before you run out and buy a bottle, here’s what you should keep in mind about taking milk of magnesia during pregnancy.

What is milk of magnesia?

Milk of magnesia — i.e. magnesium hydroxide — is a laxative that’s used to treat the occasional bout of constipation.

The medication works by drawing water into the bowel, which helps soften and pass the stool, usually within 30 minutes to six hours after taking the recommended dose.

While you can buy milk of magnesia over-the-counter in liquid or tablet form, you should always talk to your doctor before trying it, since not all OTC meds are safe for pregnant women.

What is milk of magnesia used for during pregnancy?

Milk of magnesia is often used to treat short-term constipation, which is a fairly typical pregnancy symptom. Blame pregnancy hormones like progesterone, which can slow down the passage of food and cause a build-up of waste in the GI tract. Iron supplements are another cause of constipation in pregnant women.

In some cases, magnesium hydroxide can be paired with other medications and used as an antacid, which helps relieve symptoms like heartburn and indigestion.

Is taking milk of magnesia during pregnancy safe?

In general, milk of magnesia is considered safe to use during pregnancy, but you should always double-check with your doctor before taking it.

It’s possible for the laxative to interact with medications you’re currently using. It can also cause complications for people on magnesium-restricted diets and for those who have kidney disease.

Be sure to take milk of magnesia exactly as directed. Using too much of a laxative can cause side effects like abdominal pain, vomiting and diarrhea, or, in very rare cases, coma or death.

And no one — pregnant or not — should take milk of magnesia for longer than a week unless they’ve been told to do so by their doctor.

What dosage of milk of magnesia is safe during pregnancy?

Milk of magnesia is usually taken as a single dose at bedtime, though it can also be split into two or more doses and taken throughout the day.

Some brands recommend taking 1 to 4 tablespoons of the liquid version of milk of magnesia along with an 8-ounce glass of water per dose.

Regardless of how you divvy up the doses, don’t take more than the maximum daily amount in any 24 hour-period.

And remember, if you’re pregnant, talk to your doctor before taking any dose, and follow your provider's instructions as well as the directions on the label.

What constipation remedies are okay to use during pregnancy?

There’s no such thing as a medication that’s 100 percent safe for pregnant women — which is why it’s a good idea to try to treat your constipation by changing up your diet or exercise routine first.

If that doesn't work, however, there are a few other laxatives available on the market that are generally considered safe to use during pregnancy. Talk to your practitioner before taking any of them.

In the meantime, here’s what you can do to try to regulate your bowel movements while you’re pregnant:

  • Fill up on fiber. Adding roughage to your diet in the form of whole grains, fruit, vegetables and legumes can help bulk up your stool and move it faster through your intestines. Women should aim for at least 25 grams of fiber a day. Be sure to consume both soluble and insoluble sources of fiber, though, as too much insoluble fiber (especially on an empty stomach) may cause tummy trouble in some people.
  • Drink up. Upping your fluid intake can help usher food through the digestive tract and soften your stools, making them easier to pass. Try to drink 10 8-ounce glasses of fluids a day.
  • Get up and go. Exercise can increase the muscle activity in your intestine, which can then help move waste out of your GI tract.
  • Talk to your doctor about taking a bulk-forming laxative. Fiber supplements like Citrucel and Metamucil work by absorbing water, prompting your body to naturally pass stool.
  • Ask your provider if you should take a stool softener. Meds like Colace and Surfak work by adding moisture to the stool, making the waste easier to pass.

Avoid stimulant laxatives like Dulcolax or Senokot, which trigger the intestinal muscles to contract and can be harmful to pregnant women.

The side effects of milk of magnesia during pregnancy can be the same as those for the non-pregnant population. These can include:

  • Bloating
  • Cramping
  • Nausea
  • Gas
  • Increased thirst
  • Loose or watery stools
  • Diarrhea or more frequent bowel movements

Some of the more serious side effects that warrant a call to your doctor right away include:

  • Blood in the stool
  • An inability to have a bowel movement six hours after taking the medication

Benefits of taking milk of magnesia during pregnancy

Milk of magnesia is known to ease constipation — an all-too-familiar symptom that can crop up starting in the second and third month of pregnancy. And unlike the stimulant laxatives, saline laxatives like milk of magnesia are generally considered safe to use during pregnancy.

Here are some of the benefits of milk of magnesia during pregnancy:

  • Relieves constipation, usually within 30 minutes to six hours
  • Eases heartburn symptoms when used as an antacid
  • Soothes an upset stomach when used as an antacid

Risks of taking milk of magnesia during pregnancy

It’s not known for certain whether taking milk of magnesia can harm a developing fetus — after all, pregnant women don’t make ideal research subjects — but doctors generally believe that the medication is safe to use during pregnancy. Just make sure you get the green light from your health care provider before trying it.

While it’s possible for milk of magnesia to trigger side effects like bloating and diarrhea, there are a few more serious issues that could arise, including:

  • Electrolyte imbalances when taken for long periods of time
  • Heart rhythm disturbances in people who have kidney problems
  • Trouble controlling your bowel movements, including an inability to go to the bathroom without using laxatives

When to call the doctor

If you’re experiencing loose, watery stools that don’t go away, blood in your stools, or an inability to have a bowel movement six or more hours after taking the medication, call your doctor right away.

And remember: When you’re pregnant, there’s really no such thing as being too careful. If any unusual symptoms appear after using the laxative, make the call.

In general, milk of magnesia is considered safe to take during pregnancy. Still, you should always talk to your practitioner before using it or any other type of laxative.

If your doctor gives you the thumbs-up, make sure you follow the directions on the label as well as your provider’s marching orders.

What laxative is safe during pregnancy

Medically reviewed by Holly Ernst, P.A.Written by Nicole Galan, RN on February 6, 2019

  • Causes
  • Home remedies
  • Other treatments
  • Complications
  • When to see a doctor

Constipation is a very common symptom that many women experience during pregnancy.

Some women have constipation at an early stage of their pregnancy, while it does not affect other women until much later on.

In this article, we explain why constipation is common in pregnancy and discuss safe treatments and home remedies that women can use to relieve the discomfort.

What laxative is safe during pregnancy
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The cause of constipation during pregnancy depends on the stage at which it occurs. Possible causes include:

  • Hormones: Changing hormone levels in early pregnancy cause the intestines to slow down the movement of stool through the bowel. This delay increases the amount of water that the colon absorbs from the stool, which makes it more solid and difficult to pass.
  • Prenatal vitamins: Prenatal vitamins are chock-full of iron, a crucial mineral that can sometimes be deficient during pregnancy. Iron can cause constipation and hard, black stools.
  • Pressure from the uterus: In later pregnancy, the growing uterus can put pressure on the bowel, making it harder to move stool through the intestines.

In addition to infrequent bowel movements, constipation can cause bloating, stomach discomfort, and hard, dry stools that are painful to pass. It can also result in a feeling that not all the stool has passed.

Constipation can be particularly uncomfortable during pregnancy.

During pregnancy, women can often relieve constipation using gentle, safe home remedies:

  • Fiber: Taking fiber supplements or eating more fibrous foods, such as fruits, vegetables, and whole grains, can increase the number of stools and facilitate their passage through the intestines. Adults should eat between 28 and 34 grams of fiber each day.
  • Fluid: Drinking enough water is important to keep stool soft and easy to pass. If a person feels that water is not helping, they can try adding clear soups, teas, and naturally sweetened fruit or vegetable juices to their diet.
  • Activity: Being active helps stool move through the intestines. Getting regular exercise, with a doctor’s approval, can help relieve constipation. If exercising is not a priority or possibility, try to fit in a gentle walk each day.
  • Probiotics: Millions of healthy bacteria live in the gut and help it function correctly. Probiotics may help repopulate the gut bacteria with healthy strains that encourage normal and regular bowel movements. Foods high in probiotics include yogurt, sauerkraut, and kimchi.

If the home remedies above do not work, it may be time to discuss other options with a doctor.

For women taking prenatal vitamins that are high in iron, doctors may recommend trying a vitamin that contains less iron.

The primary medical treatment for constipation in pregnancy is a medication called a laxative, which makes it easier and more comfortable to go to the bathroom.

It is generally safe to use gentle laxatives, but it is best to avoid stimulant laxatives because they can induce uterine contractions.

Although many laxatives are available over the counter, it is important to check with a doctor which one is safe to use. Limited information is available about using some of these medications during pregnancy.

Women can usually safely use the following types of laxative during pregnancy:

Bulk-forming agents

Bulk-forming agents mimic fiber by adding material to the stool and helping it absorb more water. By doing this, they make the stool larger, softer, and easier to pass.

These types of laxative can cause some cramping or discomfort, so people should start with the lowest dosage and ensure that they drink lots of water.

Examples of bulk-forming agents include psyllium, methylcellulose, and polycarbophil.

Stool softeners

Stool softeners add water to the stool to help make it softer and more comfortable to pass.

The stool softener that doctors most commonly recommend to pregnant women is docusate (Colace).

Lubricant laxatives

Lubricant laxatives add a slippery coating to either the stool or the inside of the intestinal tract to aid the passage of stool out of the body.

Glycerin suppositories are one type of lubricant laxative. It is essential to always speak to a healthcare professional before using suppositories, especially when pregnant.

Osmotic laxatives

By drawing more water into the intestines, these laxatives help soften the stool. They also allow the bowel to contract more to move the stool along. These types of laxative can also cause cramping and bloating in the abdomen.

Examples of osmotic laxatives include polyethylene glycol and magnesium hydroxide.

In most cases, constipation in pregnancy is short-lived and resolves with no or minimal treatment. In rare cases, however, prolonged constipation can cause fecal impaction, which may need removal by a doctor.

Continued use of certain types of laxative can cause the bowel to “forget” how to push stool through the intestines.

These drugs can also cause electrolyte or fluid imbalances in some people. Such issues usually affect people who have other health problems, such as diabetes or kidney disease.

It is best to speak to a doctor about the types of laxative to take and how often to take them.

It is vital that pregnant women speak with their doctor before taking any medication, including laxatives or other constipation remedies.

Seeing a doctor is also advisable if any additional symptoms occur, including:

  • nausea
  • stomach pain
  • vomiting
  • constipation that lasts for longer than 1–2 weeks
  • bleeding from the rectum
  • no relief after using a laxative

As always, mention any other symptoms or concerns to the doctor for more specific information and advice.

Last medically reviewed on February 6, 2019