In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to meclizine may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What is meclizine?
Meclizine is a medication used to treat nausea and vomiting, motion sickness, and vertigo (a feeling of whirling and loss of balance). The medication is an antihistamine (medication used to stop some allergic or cold symptoms) and might cause drowziness. Meclizine comes in several over-the-counter (OTC) products including Dramamine® Less Drowsy, and Bonine®. It is important to check the label of all OTC products to ensure the ingredients have not changed.

I just found out I am pregnant. Should I stop taking meclizine?
You should always talk with your healthcare provider before making any changes in your medications. It is important to consider the benefit of treatment for any nausea and vomiting you might have, especially if it is making it hard for you to function on a day to day basis. For more information on nausea and vomiting in pregnancy, please see the MotherToBaby Fact Sheet Nausea and Vomiting in Pregnancy at http://mothertobaby.org/fact-sheets/nausea-vomiting-pregnancy-nvp/pdf/

Can use of meclizine during pregnancy cause birth defects?
Based on the data available, meclizine does not seem to cause an increased chance for birth defects when used in pregnancy.

Can use of meclizine cause other pregnancy complications?
There are no data looking at the use of meclizine and the chance for other complications to a pregnancy.

Can I take meclizine while breastfeeding?
There is limited information on the use of meclizine while breastfeeding. Occasional doses of meclizine while breastfeeding are unlikely to cause a problem for your baby. However, if you need to use this medicine often or in large doses, talk with your health care provider. It is possible, but not proven, that antihistamines in general may lower the amount of milk a woman makes. This might be more likely to occur if antihistamines are used in combination with an oral decongestant like pseudoephedrine (Sudafed®), or if used before breastfeeding is fully established (when baby is first born). Be sure to talk to your health care provider about all your choices for breastfeeding.

What if the father of the baby takes meclizine?
There are no studies looking at how a man’s use of meclizine would affect his fertility or a partner’s pregnancy. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures and Pregnancy at http://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/pdf/.

References:

  • Gilboa SM, et al. 2009. National Birth Defects Prevention Study: Use of antihistamine medications during early pregnancy and isolated major malformations. Birth Defects Res A Clin Mol Teratol 85(2):137-150.
  • Ito S, et al. 1993. Prospective follow-up of adverse reactions in breast-fed infants exposed to maternal medication. Am J Obstet Gynecol; 168:1393-9.
  • Kallen B, Mottet I. 2003. Delivery outcome after the use of meclozine in early pregnancy. Eur J Epidemiol 18:665-669.
  • King CT, et al. 1965. Antihistamines and teratogenicity in the rat. J Pharmacol Exp Ther; 147:391-8.
  • Lenz W. 1966. Malformations caused by drugs in pregnancy. Am J Dis Child; 112:99-106.
  • Messinis IE, et al. 1985. Histamine H1 receptor participation in the control of prolactin secretion in postpartum. J Endocrinol Investig;8:143-6
  • Michaelis J, et al. 1983. Prospective study of suspected associations between certain drugs administered during early pregnancy and congenital malformations. Teratology 27:57-64.
  • Wilk AL, et al. 1978. Chlorcyclizine induction of cleft palate in the rat: degradation of palatal glycosaminoglycans. Teratology; 18(2):199-209.