Safety of Antihistamines During Pregnancy

If you're pregnant, you may wonder if it's safe to use antihistamines. These are commonly used to treat allergic rhinitis as well as insomnia, nausea, vomiting, motion sickness, and dizziness. Nearly 15% of pregnant women report taking an antihistamine during their first trimester.

Studies have shown that most antihistamines do not appear to be linked to birth defects and that certain medications, such as Zyrtec (cetirizine) and Claritin (loratadine), may be safe to use during pregnancy.

A pregnant business woman blowing her nose
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Study of Antihistamines in Pregnancy

A group of researchers from Boston Massachusetts and Singapore sought to determine the safety of antihistamines taken during the first trimester of pregnancy.

The data from this study is extremely encouraging that antihistamines are generally considered safe during pregnancy. The previous associations between antihistamine use during the first trimester and birth defects was not confirmed in this study.

The researchers examined data collected over a 12-year period of time, from 1998 to 2010, on over 13,000 babies born with birth defects, and compared them to nearly 7,000 babies without birth defects.

Approximately 14% of all babies had been exposed to various antihistamines the mother took during the first trimester of pregnancy. Some antihistamines, such as Benadryl and Claritin, have increased in pregnancy use over the years, while the use of other antihistamines, such as Chlor-Trimeton and Unisom has decreased.

However, in an attempt to assess the risk of developing other common birth defects, the researchers did find an association between the use of Chlor-Trimeton and any neural tube defect and with various congenital heart malformations.

There was also an association between the use of Benadryl and one type of congenital heart malformation (transposition of the great arteries). However, the authors are careful to point out that these are only hypotheses that require further study.

In a 2014 study conducted by the Centers for Disease Control and Prevention (CDC), researchers reviewed 54 published scientific articles that examined the link between antihistamine use during pregnancy and birth defects.

They found that the use of most types of antihistamines during pregnancy is not linked to birth defects. However, the researchers noted that certain antihistamine medications need to be further studied to determine their safety in pregnancy.

According to the American College of Obstetricians and Gynecologists (ACOG), studies show that the following over-the-counter antihistamine medications may be safe to use while pregnant:

  • Chlorphenamine
  • Dexchlorpheniramine
  • Hydroxyzine
  • Cetirizine
  • Loratadine

Although research suggests that many antihistamines are generally considered “safe” during pregnancy, it's recommended that you consult with your healthcare provider before taking any over-the-counter medications.

Possible Associations Between Antihistamines and Birth Defects

Associations between antihistamines taken during the first trimester of pregnancy and certain birth defects include:

  • Diphenhydramine (Benadryl): Cleft lip and cleft palate, neural tube defects, spina bifida, limb reduction defects, gastroschisis.
  • Loratadine (Claritin): Hypospadias.
  • Chlorpheniramine (Chlor-Trimeton): Eye defects, ear defects, spina bifida, cleft lip, and cleft palate.
  • Doxylamine (Unisom): Cleft lip and cleft palate, pyloric stenosis, hypoplastic left heart syndrome, spina bifida, and neural tube defects.

Even though most antihistamines are available OTC without a prescription, pregnant women should seek the advice of a physician prior to taking any medication, particularly during the first trimester of pregnancy.

Any medication taken during pregnancy is best taken for the shortest amount of time, and at the lowest dose that is effective for treating symptoms. The benefit of taking any medication needs to be weighed against the risk of not taking the medication.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Gilboa SM, Ailes EC, Rai RP, Anderson JA, Honein MA. Antihistamines and birth defects: a systematic review of the literatureExpert Opinion on Drug Safety. 2014;13(12):1667-1698. doi:10.1517/14740338.2014.970164

  2. Li Q, Mitchell AA, Werler MM, Yau WP, Hernández-Díaz S. Assessment of antihistamine use in early pregnancy and birth defectsJ Allergy Clin Immunol Pract. 2013;1(6):666–74.e1. doi:10.1016/j.jaip.2013.07.008

  3. American College of Obstetricians and Gynecologists (ACOG). What medicine can I take for allergies while I'm pregnant?

By Daniel More, MD
Daniel More, MD, is a board-certified allergist and clinical immunologist. He is an assistant clinical professor at the University of California, San Francisco School of Medicine and currently practices at Central Coast Allergy and Asthma in Salinas, California.