In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to pseudoephedrine or phenylephrine may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What are pseudoephedrine and phenylephrine?

Pseudoephedrine and phenylephrine are decongestants. They are often used to treat nasal congestion (“stuffy nose”) caused by colds or allergies. Pseudoephedrine is sold under brand names such as Sudafed®, Drixoral Nasal Decongestant ® and Myfedrine®. Pseudoephedrine can also be combined with other ingredients to help treat other symptoms that may come with having a cold or allergies. In many places, products containing pseudoephedrine are only available upon request behind the pharmacy counter. Phenylephrine is a different form of pseudoephedrine. It has replaced pseudoephedrine in many cold medications that are available on the shelves.

Can using pseudoephedrine or phenylephrine increase the risk of miscarriage or make it more difficult for me to become pregnant?

There are no studies looking at whether these decongestants could make it harder to get pregnant or if they would increase the risk of miscarriage.

I am in my first trimester of pregnancy and have a very stuffy nose. Will taking pseudoephedrine cause birth defects?

Probably not. However, until more information is available it is better not to take pseudoephedrine in the first trimester.

Most studies have not found an increased risk for birth defects. However, some studies have found a small increased risk for specific birth defects. These birth defects are: gastroschisis (an opening in the baby’s abdominal wall), small intestinal atresia (part of the small intestine is not fully developed) and hemifacial microsomia (part of the face is smaller than it should be). If you have already taken pseudoephedrine in the first trimester, remember that the risk for these birth defects, if any at all, is very small.

Is it true that smoking can increase the risk of birth defects related to the use of pseudoephedrine?

Possibly. One study showed that when a mother who smokes cigarettes also takes pseudoephedrine, the risk of having a child with gastroschisis may be greater than if she was exposed to either one alone. However, the risk is considered very low.

Does using phenylephrine in the first trimester cause birth defects?

Probably not. Two studies involving more than 1500 women who took phenylephrine in the first trimester did not show an increased chance for birth defects. However, studies have not looked at whether phenylephrine use is possibly associated with birth defects like gastroschisis.

I am 8 months pregnant and for the past few days I have been suffering from a cold. Can I use pseudoephedrine or phenylephrine to relieve my nasal congestion?

You should always speak with your health care provider before you start or stop taking any medication.

If you use a decongestant after the first trimester, it is best to choose one that contains only pseudoephedrine or phenylephrine (not one with many active ingredients). This avoids exposing the baby to other medications that may not be needed. Never take more than the recommended dose. The dose is found on the product label. Talk to your health care provider if you have questions about how much to take.

Because both pseudoephedrine and phenylephrine constrict blood vessels, you should not use them if you have high blood pressure. Your health care provider can help you choose the medication that is best for you.

Can I use pseudoephedrine or phenylephrine if I am breastfeeding?

At recommended doses, only a small amount of pseudoephedrine gets into breast milk. In general, pseudoephedrine does not cause any side effects in the breastfed baby, but a few cases of irritability have been reported.

Pseudoephedrine may reduce the amount of milk that you produce. Given this concern, it may be best to wait to use pseudoephedrine until breastfeeding is well established. If you notice a decrease in your milk supply, pseudoephedrine use should be stopped.

There are no studies looking at the use of phenylephrine in breastfeeding mothers. Studies in animals have shown that like pseudoephedrine, phenylephrine may reduce milk supply. Because there is little information about the safety of phenylephrine while breastfeeding, use of nasal sprays or short term use of pseudoephedrine may be preferred. Be sure to talk to your health care provider about all your breastfeeding questions.

What if the father of the baby takes pseudoephedrine or phenylephrine?

There are no studies looking at possible risks to a pregnancy when a father takes pseudoephedrine or phenylephrine, but a father’s use of these common decongestants is not expected to cause birth defects. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures and Pregnancy at

References Available By Request.