Ask an expert: What’s safe to take during pregnancy?

May 18, 2017 Providence Health Team


In this article:

  • Patients have many questions regarding the safety of prescription and over-the-counter medications as well as supplements while pregnant.

  • The Food and Drug Administration (FDA) classifies the known safety level of drugs for pregnant women with a lettering system -- classes A, B, C, D, and X. This includes antidepressants, cold and cough medicines, and even dental anesthesia.

  • Angela Keating, M.D., board-certified obstetrician/gynecologist with Providence Women's Clinic, explains the factors that determine the effects of a medication on your developing baby.

The Providence Ask an Expert series addresses topics that are top of mind with members of the Providence community. We take real questions from real people and partner with providers to get the answers.

During my pregnancy, is it safe for me to use …

  • Antidepressants?
  • Milk of magnesia?
  • Gas-X or other anti-gas medications?
  • Maalox?
  • Os-Cal, Caltrate or other calcium supplements?
  • Cold and cough medicines?
  • Metrogel to treat bacterial vaginosis?
  • Lunestra or other sleep medications?
  • Folic acid supplements?
  • Dental anesthesia?

Answers from Angela Keating, M.D., board-certified obstetrician/gynecologist with Providence Women's Clinic:

It's good to ask these questions. Many (but not all) substances taken during pregnancy will reach the fetus via the placenta. The effects of a medication on your developing baby depend on several factors:

  • The medication itself
  • The amount that you take
  • The length of time that you take it
  • The stage of your pregnancy when you take it (the first trimester calls for the most caution, because it is the critical period of development for the baby's brain and other organs; however, certain medications can cause problems at any time during pregnancy)

Of the substances that do reach the fetus through the placenta, scientists have been able to confirm some that are safe for the developing baby and some that pose a health risk. For most substances, however, the level of risk or safety is still unknown.

The Food and Drug Administration (FDA) classifies the known safety level of drugs for pregnant women using the following lettering system:

  • Class A: Controlled human studies have demonstrated no risks to the fetus.
  • Class B: Presumed safe, based on animal studies; no well-controlled human studies are available.
  • Class C: Safety is uncertain; data from human studies do not exist, and animal studies have shown some question of risk to the fetus. Pregnant women may take these medicines if they clearly need them.
  • Class D: Evidence suggests the possibility of the medication causing birth defects or other problems, but a pregnant woman still might need to take it for her own medical needs.
  • Class X: Proven risks to the fetus outweigh any possible benefits to the mother.

In general, if obstetricians can't say with certainty that a substance is safe for developing babies, we advise pregnant women to avoid taking it, if possible. In each case, however, we weigh the risk to the fetus against the benefits to the mother.


If you are pregnant and suffer from depression, it's better to treat the depression than not. When your depression is under control, you are in a stronger position to nurture both your body and your developing baby. We certainly try non-medical approaches to managing depression, including psychotherapy and evaluating and addressing any social factors (home life, work life, friendships) that may be contributing to your depression. When pregnant women do need antidepressants, physicians commonly prescribe a drug from the family of “selective serotonin uptake inhibitors,” or SSRIs (Celexa, Lexapro, Paxil, Prozac, Zoloft) or Wellbutrin (generic name “bupropion,” an aminoketone), which is a different class from the SSRIs.

Physicians prefer the SSRIs and Wellbutrin for pregnant women for a few reasons:

  • Compared to the older tricyclics, they are more effective, safer, present fewer side effects and are available in a wider range of doses.
  • The FDA rates SSRIs as Class C medications, but because the majority of women taking antidepressants take SSRIs, we have a great deal of current information on them.
  • Wellbutrin is a Class B drug.

Some scientific literature shows possible short-term problems with infants who were exposed to these medications in the womb. We recommend that you talk with your health care provider about the advantages and drawbacks of these medications versus the risks of depression during pregnancy or after childbirth. (Depending on its severity, postpartum depression can be a very serious matter.)

If you take Paxil, ask your doctor to discuss a recent study about its risks during pregnancy. Research is scant on herbal supplements used to lift mood, so we recommend avoiding those.

Milk of Magnesia or other laxatives

We generally do not recommend laxatives for pregnant women, although providers may recommend them under special circumstances. (Some physicians recommend them sooner than others.) We are cautious with laxatives because their regular use can make your intestinal system dependent on them. Of special concern during pregnancy, laxatives can cause intestinal cramping that may be hard to differentiate from preterm labor.

That said, you are not alone in dealing with constipation during pregnancy. Many pregnant women have it, to varying degrees, and we have several suggestions that may help relieve the problem. Our first recommendation is to drink more fluids—about three quarts a day. Most of that should be water. Fiber-rich foods also are good for reducing constipation. Eat more fruits and vegetables, whole-grain bread (check the wrapper for at least 3 grams of fiber per slice), brown rice, oat bran, and beans (pinto, garbanzo, kidney, and the like).

If you increase fluids and fiber in your diet and still have problems, then you can try a supplement, such as fiber pills (FiberCon is one example) or fiber powders (such as Metamucil) that can be mixed with liquid. These steps will relieve most pregnancy-related constipation.

However, if you still need help after these measures, try a stool softener, such as Colace. Stool softeners are available without a prescription. If that also fails, talk with your provider about laxatives, including Milk of Magnesia. Yes, Milk of Magnesia is safe and will quickly fix the problem—but it isn't the best long-term solution during pregnancy for the reasons we described above. So, we prefer it far down the list of strategies.

Gas-X or other anti-gas medications

Gas-X and other anti-gas meds (Phazyme, Flatulex, Mylicon, Mylanta Gas) relieve abdominal pain caused by excessive gas in the digestive tract. Their active ingredient is simethicone, which is safe during pregnancy. But before trying any medication, we recommend looking at your diet and eliminating or cutting back on foods that increase gas.


Maalox is an antacid for relieving heartburn. Pregnancy, as you may discover, often causes or worsens acid reflux. That's because progesterone—a pregnancy hormone—relaxes the valve that ordinarily acts as a gatekeeper between the stomach and the esophagus (food pipe). When this valve is relaxed, stomach acid sneaks back up into the esophagus, causing a burning sensation. To make matters worse, in the second and third trimesters of pregnancy, the growing fetus pushes on the stomach and intestines, which can increase these symptoms.

In general, we recommend avoiding foods that increase your reflux (often acidic foods or drinks, or foods that are fried, spicy or fatty). It also helps to wear loose clothing and to sit upright for a couple of hours after you eat.

If you have only occasional symptoms, our first recommendation is a calcium-containing antacid such as Tums. Using Maalox occasionally during pregnancy is OK, too.

If you have symptoms every day, we recommend that you discuss this with your provider, who may suggest a preventive medication such as Zantac or something similar. A medical evaluation also might be advised to make sure you don’t have another underlying problem that is causing the acid reflux.

Os-Cal, Caltrate, and other calcium supplements

Calcium supplements such as Os-Cal and Caltrate are fine to take while you’re pregnant. During your pregnancy, you should consume 1,200 mg to 1,500 mg of calcium daily from all sources—supplements and food. Good sources of calcium in food are dairy products (also a good source of protein) and calcium-fortified orange juice. Pinto or baked beans, greens, and broccoli also offer some calcium.

Depending on your diet and other supplements, you might want to choose a calcium supplement that also includes Vitamin D, which enhances the body’s ability to absorb calcium. Both Os-Cal and Caltrate, like many other calcium supplements, are available in formulations that contain vitamin D. We recommend 400 IU to 800 IU of vitamin D daily. Check the label of your prenatal vitamins to see how much they contain. Milk also is fortified with vitamin D. Although your skin also makes vitamin D when exposed to sunlight, it's difficult in the Northwest to get enough sun during the rainy season to trigger vitamin D production.

Cold and cough medicines

A number of nonprescription cold and cough medicines are safe during pregnancy. These include Tylenol (the FDA puts this in Class B), antihistamines such as Claritin (Class B) and saline nasal sprays (Class A).

Other medications can be used short-term, including cough medicines such as Robitussin, or decongestants with the active ingredient of pseudoephedrine or phyenylephrine (all Class C). If your symptoms last more than a week, see your medical provider for an exam and reassessment of the medicines you are taking.

Metrogel (for bacterial vaginosis)

The active ingredient in Metrogel is metronidazole. Metronidazole is commonly used to treat bacterial vaginosis. It comes in both an oral form (pill) and a vaginal gel. Historically, the medical community has used the pill form for treating pregnant women because we have data from medical studies on the pill, but not on the gel. It is a Class B medication, but the drug label information suggests avoiding its use in the first trimester. We recommend speaking with your provider about the risks vs. benefits and about the route of administration (oral or vaginal) to fit your individual situation.

Lunestra or other sleep aids

Insomnia is very common during pregnancy. Before you resort to medications, we recommend the basic measure of examining your sleep habits:

  • For best sleep, don’t exercise too close to bedtime — plan your exercise for at least two hours before you go to bed.
  • Some women sleep better after drinking a cup of warm milk or herbal tea prior to bed. About two hours before bedtime, though, start limiting the amount of fluids you drink.
  • Establish a calming bedtime ritual, and follow it each night. Head to bed only when you are tired and ready to sleep.
  • Avoid watching TV, reading or eating in bed.
  • Try listening to relaxing music or white noise, such as nature sounds.
  • As your pregnancy progresses, it will become physically more difficult for you to get comfortable enough to sleep. You may want to try a body pillow, or try placing a pillow under your abdomen and between your knees while lying on your side.
  • If you can’t fall asleep, don’t stay in bed, feeling upset and frustrated. Get up, move to another room, and read or do another quiet activity. Stay up until you feel very drowsy; only then return to bed.

It's best to avoid medications for insomnia, but if you find yourself so tired that you can’t function during the day, talk with your provider about it. You may want to consider short-term sleep aids, including Benadryl (Class B), Ambien (Class B) or Lunesta (Class C).

Folic acid

The U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Public Health Services recommend that all women of child-bearing age get 400 mcg of folic acid (folate) daily, either from vitamin supplements or from enriched foods.

They base this recommendation on evidence that, during the first month of pregnancy, folic acid can greatly reduce the risk of neural tube defects, such as spina bifida. The recommendation is extended to all women of child-bearing age—not just pregnant women—because a woman may not know she is pregnant during the first month, when folic acid is so important to the baby's development.

Women who have had a baby with a neural tube defect are generally advised to take 4,000 mcg (4 mg) daily in subsequent pregnancies. Those who are pregnant with twins or multiples should talk to their doctor about how much folate they should take.

Most prenatal vitamins contain a safe range of 400 mcg to 800 mcg of folic acid. Folic acid or folate is also found in green leafy vegetables and is added to many processed foods, including cereal and bread. Read package labels for amounts. If you have any concerns about the amount of folic acid you get daily, speak with your physician.

Dental anesthesia

Take care of your teeth and gums during pregnancy. Local anesthetics are safe, as are dental X-rays. As a precaution, obstetricians always recommend that your abdomen be shielded during dental X-rays.

Most antibiotics used by dentists are safe, too, but ask your dentist to confirm that with your obstetrician or nurse-midwife.

Other medications or supplements

You can find a medication guide that offers additional suggestions about what’s safe to take for headaches, morning sickness, congestion and other ills that may crop up during your pregnancy. Whether you are pregnant or are planning to get pregnant, if you have any questions about the safety of the medications or supplements you take, please talk to your health care provider right away.


Find a Doctor

If you have questions or concerns about specific medications, we recommend that you talk to your doctor just to be sure. If you don’t have a doctor, you can find one in our provider directory.

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This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.


About the Author

The Providence Health Team brings together caregivers from diverse backgrounds to bring you clinically-sound, data-driven advice to help you live your happiest and healthiest selves.

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