This sheet is about exposure to diphenhydramine in pregnancy and while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare provider.
What is diphenhydramine?
Diphenhydramine is an antihistamine medication that has been used to treat allergy symptoms, nausea, motion sickness, insomnia, itchy skin, migraine, and tremors related to Parkinson’s disease. Diphenhydramine is found in many prescriptions and over the counter products. Some brand names for diphenhydramine include Benadryl®, Dormin®, Unisom®, Sominex®, and Nytol®.
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 your 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 diphenhydramine. Can it make it harder for me to get pregnant?
It is not known if diphenhydramine can make it harder to get pregnant.
Does taking diphenhydramine increase the chance of miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Results from one study did not show an increased chance of miscarriage with the use of antihistamines, including diphenhydramine, in early pregnancy.
Does taking diphenhydramine increase the chance of birth defects?
Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like diphenhydramine, might increase the chance of birth defects in a pregnancy.
A few studies have suggested a higher chance of birth defects when diphenhydramine is used during the first trimester. However, these studies do not all agree, and no consistent pattern of birth defects has been noted. There are also several studies that reported no increased chance of birth defects with the use of diphenhydramine in early pregnancy.
Does taking diphenhydramine in pregnancy increase the chance of other pregnancy-related problems?
Occasional use of diphenhydramine at recommended doses is not expected to increase the chance of other 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).
There are reports of other issues, including uterine contractions and, very rarely, fetal death with the use of diphenhydramine in the third trimester. However, these reports usually involve using more of the medication than is recommended or using it for longer than the recommended time.
Can I take diphenhydramine with a benzodiazepine?
There is a single human report and animal data that has suggested that the combination of a medication called temazepam (a benzodiazepine) and diphenhydramine might increase the chance of stillbirth or infant death shortly after birth. It has been recommended that these two medications not be used together during pregnancy. People taking temazepam should talk with their healthcare provider before taking diphenhydramine during their pregnancy. MotherToBaby has a fact sheet on temazepam here: https://mothertobaby.org/fact-sheets/temazepam-restoril/.
I need to take diphenhydramine throughout my entire pregnancy. Will it cause symptoms in my baby after birth?
The use of diphenhydramine during pregnancy can cause temporary symptoms in newborns soon after birth. These symptoms are sometimes referred to as withdrawal. There are a few reports of withdrawal symptoms (tremors and diarrhea) in infants who were exposed to diphenhydramine daily throughout pregnancy. Not all babies exposed to diphenhydramine will have these symptoms. It is important that your healthcare providers know you are taking diphenhydramine so that if symptoms occur your baby can get the care that is best for them.
Does taking diphenhydramine in pregnancy affect future behavior or learning for the child?
It is not known if diphenhydramine can increase the chance of behavior or learning issues for the child.
Breastfeeding while taking diphenhydramine:
Diphenhydramine passes into breastmilk in small amounts. This medication can cause sleepiness in adults as well as the nursing baby. Two studies reported irritability and changes in sleep patterns in breastfed babies exposed to antihistamines, including diphenhydramine. Short-term or occasional use of diphenhydramine is not expected to increase the chance of side effects. If you suspect the baby has any symptoms (irritability, changes in sleep patterns), contact the child’s healthcare provider. If you need to take an antihistamine regularly, talk with your healthcare provider about which medication is best for you. Be sure to talk to your healthcare provider about all your breastfeeding questions.
If a man takes diphenhydramine, could it affect fertility or increase the chance of birth defects?
Studies have not been done to see if diphenhydramine could affect men’s fertility (ability to get a partner pregnant) or increase the chance of birth defects. In general, exposures that fathers or sperm donors 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/.
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