Diphenhydramine in Pregnancy and Breastfeeding
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Diphenhydramine (Benadryl®)

SUMMARY: Diphenhydramine is considered safe for use in pregnancy when used at the recommended dosage.

Antihistamine. Molecular weight:255.36

Diphenhydramine may cause uterine irritability or contractions near term when used in high doses (greater than 50mg) [1,2]

In 1974 Saxen reported that a study group of 599 infants with oral clefting were more likely to have been exposed to diphenhydramine during the first trimester than a control group of infants without clefting [3]. Subsequent retrospective studies of more than 2300 infants have found no association between first trimester exposure to diphenhydramine and oral clefting or major malformations [4-6]

Stillbirth has been reported following the use of diphenhydramine and temazepam during human pregnancy. The toxicity of this combination was confirmed in pregnant rabbits [7].

BREAST FEEDING: The manufacturer considers diphenhydramine to be contraindicated during breast feeding.

NEONATAL SIDE EFFECTS: Potential for severe sedation if administered to the mother before delivery [8].


1. Hara GS et al. J Kans Med Soc. 1980;81:134-6,155.  MEDLINE
2. Brost BC, Diphenhydramine overdose during pregnancy: lessons from the past. Am J Obstet Gynecol. 1996;175:1376-7.  MEDLINE
3. Saxen I: Cleft palate and maternal diphenhydramine intake. [Letter] Lancet. 1974;1:407-8.  MEDLINE
4. Heinonen OP et al.: Birth Defects and Drugs in Pregnancy, Littleton Publishing Sciences Group, 1977, pp 322-7.
5. Aselton P et al. First-trimester drug use and congenital disorders. Obstet Gynecol.1985;65:451-5. MEDLINE
6. Briggs GG,Freeman RK, Yaffe SJ, Drugs in Pregnancy and Lactation 6th edition,Baltimore, MD: Williams & Wilkins,2002 p 426.
7. Kargas GA, Perinatal mortality due to interaction of diphenhydramine and temazepam. [Letter] N Engl J Med. 1985;313:1417-8. MEDLINE
8. Miller AA Diphenhydramine toxicity in a newborn: a case report. J Perinatol. 2000;20:390-1.  MEDLINE

Created: 11/27/2002
Update: 11/30/2003
Update: 6/26/2007 Mark Curran, M.D. FACOG

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