Reproductive animal studies with chlorpheniramine demonstrated no harm to the fetus. Reproductive animal studies have not been reported with methscopolamine and phenylephrine. There are no controlled data in human pregnancy.

The Collaborative Perinatal Project monitored 1,070 first trimester exposures and 3,931 exposures which occurred anytime during pregnancy. No evidence was found to suggest a relationship to large categories of malformations. Antihistamine exposure in the first trimester in general was not associated with an increased risk of malformations.

Chlorpheniramine/methscopolamine/phenylephrine has been assigned to pregnancy category C by the FDA. Chlorpheniramine/methscopolamine/phenylephrine is only recommended for use during pregnancy when benefit outweighs risk.

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Small amounts of sympathomimetic amines and antihistamines are excreted in breast milk and because of the risk of adverse reactions in nursing infants (excitement or irritability), use is not recommended. Anticholinergics and antihistamines may inhibit lactation.

See references