Diphenhydramine While Pregnant: Is It Safe During Pregnancy?

Last Updated: July 16, 2020

Authored by Sharon Levy, MD, MPH

Being an antihistamine, diphenhydramine is commonly used to alleviate symptoms of allergies. It is effective against a range of medical conditions, including hay fever, nausea, etc. Benadryl medication also has a sedative effect and help patients with sleeping problems. Pregnancy can weaken women’s immune system that makes it more vulnerable to a common cold or various allergies. In such situations, women often resort to taking diphenhydramine. However, the use of Benadryl while pregnant can lead to a range of side-effects, such as congenital disabilities in an unborn baby.

Can One Take Benadryl While Pregnant?

It has been proven that the use of diphenhydramine if taken according to the prescribed dosage, is safe during pregnancy. The drug is not contraindicated throughout pregnancy, only if the mother does not exceed the recommended dosage, although it is advised to avoid all such types of medicines during such crucial phases when the baby is being formed.

Benadryl Pregnancy Category

U.S. Food and Drug Administration lists Benadryl in a B category, which means that there are little to no risks associated with the use of this medicine during pregnancy, neither to the mother nor to the baby, when taken as prescribed by the doctor.

doctor in white coat is consulting beautiful pregnant woman about Benadryl

However, it is essential to note that no medication is 100% safe for consumption. Diphenhydramine is not in A class drugs list, which are considered the most harmless during pregnancy. The use of Benadryl in pregnancy has several side-effects and precautions. For example, it is recommended to avoid driving while being on Benadryl in pregnancy.

How Much Diphenhydramine Is Safe To Use During Pregnancy?

Women often wonder how much Benadryl can one take while pregnant? The dosage of diphenhydramine that is considered safe during the course of pregnancy depends on the trimester.

Benadryl Dosage During First Trimester

As per the FDA recommendations, safe Benadryl pregnancy dose is up to 25-50 mg while she is in the first trimester. The drug is to be taken orally, and the next dose is to be consumed after six hours.

Benadryl While Pregnant In The 2nd Trimester

As the woman enters the second trimester and all the way to the end of pregnancy, the dosage of diphenhydramine is recommended not to exceed 25 mg. The time between two consecutive dosages, however, stays the same throughout the pregnancy.

pregnant woman taking Benadryl pill

Benadryl While Pregnant In The 3rd Trimester

There is a common concern that the use of Benadryl while pregnant, especially during the third trimester of pregnancy can have negative impacts on the mother’s health or cause abnormalities in the baby.
Since this trimester stages are crucial phases when the baby is being formed, it is recommended to avoid the use of any medicines to reduce the risks of any complications. However, if it becomes necessary to take Benadryl in the 3rd trimester, the dosage should not exceed 25 mg. It is also advisable to contact a physician to ask about the safest alternative to Benadryl for this period.

What Are The Side-Effects Of Diphenhydramine While Pregnant?

As long as the consumption is well within the dosage recommended by the doctor, there are hardly any side effects associated with the use of Benadryl during pregnancy apart from lightheadedness, dizziness, and drowsiness.

Severe Diphenhydramine Side Effects In Pregnant

Upon excessive use of the drug, however, the side effects could be more pronounced for the pregnant women, ranging from:

  • Mental disorientation
  • Blurred vision
  • Hallucinations
  • Loss of appetite
  • Gastrointestinal Disorders
  • Palpitations

It also has been found that excessive use of this drug can cause eczema, rashes, pruritus, and other allergic reactions to Benadryl. A few of the cases have also reported the symptoms of hypotension, tachycardia, headaches, and palpitations.

Benadryl Precautions For Pregnant

What not to take with Benadryl? Pregnant women who are taking any other drug like Restoril or Temazepam should specifically be cautious of using diphenhydramine since the use of these drugs in conjunction can accentuate the probability of fetal morbidity. Moreover, excessive consumption during the first trimester has been associated with an increased likelihood of an anomaly such as that of cleft palate or lip in the newborn.

Diphenhydramine Breastfeeding Warnings

Is Benadryl safe for breastfeeding mothers? No, it is not recommended for breastfeeding women to use Benadryl. While its exact effect on the baby’s health is yet unknown, it has been found that the Benadryl active ingredient is excreted via the mother’s milk. Similar results have been reported when diphenhydramine is used in conjunction with a sympathomimetic drug. That’s why it has been contraindicated for use during the period of breastfeeding.
Diphenhydramine can’t be given to the newborn child to treat allergies according to Benadryl pediatric dosing. The lowest safe age for a kid to take diphenhydramine is 6.
Though diphenhydramine is marked safe for usage by the FDA during the course of pregnancy within the prescribed dosage, it is better to avoid such medications altogether to prevent any chances of complications. The side effects and their intensity are entirely dependent on the dosage.

Page Sources

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356948/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3619228/

Published on: June 5th, 2019

Updated on: July 16th, 2020

About Author

Sharon Levy, MD, MPH

After successful graduation from Boston University, MA, Sharon gained a Master’s degree in Public Health. Since then, Sharon devoted herself entirely to the medical niche. Sharon Levy is also a certified addiction recovery coach.


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