This sheet talks about exposure to phenylephrine in a pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.

What is phenylephrine?

Phenylephrine is a decongestant. Decongestants are often in over-the-counter medications used to treat nasal congestion (“stuffy nose”) caused by colds or allergies. Phenylephrine has also been used to treat temporary low blood pressure caused by anesthesia used during surgeries.

I take phenylephrine. Can it make it harder for me to become pregnant?

There are no studies looking at whether phenylephrine could make it harder for a woman to get pregnant.

I just found out I am pregnant. Should I stop taking phenylephrine?

Talk with your healthcare providers before making any changes to how you take this medication.

Does taking phenylephrine increase the chance of miscarriage?

Miscarriage can occur in any pregnancy. There are no studies looking at whether phenylephrine would increase the chance for a miscarriage.

Does taking phenylephrine in the first trimester increase the chance of birth defects?

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. It is unclear if taking phenylephrine increases the chance of birth defects. Studies involving more than 1,500 women who took phenylephrine in the first trimester did not show an increased chance for birth defects. There was one study on 1,249 women who took phenylephrine in the first trimester that reported a slightly higher chance for minor differences of the eyes or ears: small changes that are not a birth defect. Because phenylephrine can make blood vessels smaller, there are theoretical concerns that using this medication could reduce blood flow through the placenta (organ that grows during pregnancy to supply the developing baby with food and oxygen). Studies on other medications that work in the same way (make blood vessels smaller) have raised questions about a small chance for birth defects. If you have high blood pressure, talk to your healthcare provider about medications that would be best for you.

Could taking phenylephrine in the second or third trimester cause other pregnancy complications?

Talk with your healthcare provider before you start taking any medication. If you use a decongestant after the first trimester, it may be best to choose one that has only one active ingredient (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 healthcare providers if you have questions about how much to take.

Because phenylephrine can constrict blood vessels, using this medication could raise your blood pressure. Talk to your healthcare provider if you have high blood pressure. Your healthcare providers can help you choose the medication that is best for you.

Does taking phenylephrine in pregnancy cause any long-term problems in behavior or learning for the baby?

There are no studies looking at whether phenylephrine would affect long term development or learning.

Can I breastfeed while taking phenylephrine?

There are no studies looking at the use of phenylephrine in breastfeeding mothers. Studies in animals have shown that phenylephrine might reduce milk supply. Because there is little information about the safety of phenylephrine while breastfeeding, use of nasal sprays or other medication may be preferred. Talk with your healthcare provider about your breastfeeding questions.

If a man takes phenylephrine, could it affect his fertility (ability to get partner pregnant) or increase the chance of birth defects?

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 at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/pdf/.

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