This sheet is about exposure to promethazine in a pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.
What is promethazine?
Promethazine is a medication that has been is used to treat nausea and vomiting, motion sickness, and allergies. It has also been used for sedation (to help sleep) and for treating vertigo. Promethazine has been sold under brand names such as Phenergan®, Promethegan®, and Phenadoz®.
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.
For more information about nausea and vomiting during pregnancy, please see the MotherToBaby fact sheet at https://mothertobaby.org/fact-sheets/nausea-vomiting-pregnancy-nvp/.
I take promethazine. Can it make it harder for me to get pregnant?
It is not known if promethazine could make it harder to get pregnant.
Does taking promethazine increase the chance for miscarriage?
Miscarriage can occur in any pregnancy. One small study did not report an increased chance for miscarriage in people taking promethazine.
Does taking promethazine 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. Based on the studies reviewed, promethazine is not expected to increase the chance of birth defects above the background risk.
Does taking promethazine in pregnancy increase the chance of other pregnancy-related problems?
Based on the studies reviewed, it is not known if promethazine can cause other pregnancy-related problems, such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces at birth). Using promethazine late in pregnancy might increase the chance of slowed breathing (respiratory depression) in newborns. It is important that your healthcare providers know you are taking promethazine so that if respiratory depression happens your baby can get appropriate care.
Does taking promethazine in pregnancy affect future learning or behavior for the child?
Based on the studies reviewed, it is not known if promethazine increases the chance for behavior or learning issues. In the few studies looking at a small number of children who were exposed to promethazine while pregnant, harmful effects on the children’s learning and behavior were not reported.
Breastfeeding while taking promethazine:
Promethazine has not been studied for use while breastfeeding. Promethazine can cause sleepiness in adults and it may do the same for a nursing baby. If you suspect the baby has any symptoms (sleepiness and lack of energy), contact the child’s healthcare provider. It is possible that promethazine could reduce how much milk a person makes. If you are having trouble producing milk, talk with your healthcare provider or a lactation specialist. Be sure to talk to your healthcare providers about all of your breastfeeding questions.
If a male takes promethazine, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects?
Studies have not been done to see if promethazine could affect fertility or increase the chance of birth defects above the background risk. 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/.
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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.