This sheet is about exposure to chlorpheniramine in pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.
What is chlorpheniramine?
Chlorpheniramine is an antihistamine. Antihistamines are medications used to relieve symptoms of allergies, hay fever (allergic rhinitis), and the common cold. These symptoms include sneezing, runny nose, watery eyes, and itchy throat. Chlorpheniramine is sold under different brand names, including Chlor-Trimeton®.
Sometimes when people find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take this medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
I take chlorpheniramine. Can it make it harder for me to get pregnant?
It is not known if chlorpheniramine could make it harder to get pregnant.
Does taking chlorpheniramine increase the chance for miscarriage?
Miscarriage can occur in any pregnancy. Studies have not been done to see if chlorpheniramine increases the chance for miscarriage.
Does taking chlorpheniramine increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. It is unlikely that chlorpheniramine would cause an increased chance for birth defects. Most studies find no overall increased chance of birth defects with the use of chlorpheniramine in pregnancy. While two studies found a small increased chance for different types of birth defects, no specific pattern of birth defects has been reported.
Does taking chlorpheniramine in pregnancy increase the chance of other pregnancy-related problems?
Studies have not been done to see if chlorpheniramine increases the chance for pregnancy-related problems such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces (2500 grams) at birth).
Does taking chlorpheniramine in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if chlorpheniramine can cause behavior or learning issues for the child.
Breastfeeding while taking chlorpheniramine:
It is possible, but not proven, that antihistamines in general may reduce the amount of breast milk that is made. This might be more likely to happen when used in combination with a decongestant like pseudoephedrine or phenylephrine, or if used before breastfeeding is established. Small doses (2mg to 4 mg), taken occasionally, are considered compatible with breastfeeding. There is not enough information to know if or how larger doses or taking small doses every day would affect a nursing child or milk production.
Chlorpheniramine can cause sleepiness in adults, and it is possible that in higher doses, it may do the same for a nursing baby. For this reason, it may not be a preferred antihistamine for long-term use during breastfeeding. If you need to take an antihistamine regularly while breastfeeding, talk with your healthcare provider about which one would be best for you.
Five people who were breastfeeding while using chlorpheniramine were asked about their child’s behavior. No problems with behavior were reported in any of the children exposed to chlorpheniramine through breastmilk. Be sure to talk to your healthcare provider about all of your breastfeeding questions.
If a male takes chlorpheniramine, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects?
Studies have not been done to see if chlorpheniramine could affect male fertility or increase the chance of birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
Please click here to view references.
OTIS/MotherToBaby encourages inclusive and person-centered language. While our name still contains a reference to mothers, we are updating our resources with more inclusive terms. Use of the term mother or maternal refers to a person who is pregnant. Use of the term father or paternal refers to a person who contributes sperm.
