According to a new study published in the American Journal of Epidemiology, over-the-counter decongestants may be a cause for concern when used in the first trimester of pregnancy. The study shows a link between rare birth defects, including defects of the ear, digestive tract, and heart, with first-trimester decongestant use.

Dr. Allen Mitchell used data collected at Boston University as part of a birth defects study as research. Mitchell compared more than 12,000 malformed infants to about 7,600 infants with no malformations. Interviews were conducted to assess whether or not mothers of infants with and without malformations used over-the-counter decongestants during pregnancy.

The most common decongestant used was pseudoephedrine, but mothers also reported using phenylephrine, phenylpropanolamine, and imidazolines. Sudafed, a brand-name decongestant that contains both phenylephrine and pseudoephedrine was associated with an increased risk of a heart defect and limb reduction defect. Specifically, phenylephrine was shown to increase the risk of heart defect eight-fold and pseudoephedrine was associated with a three-fold increased risk of limb defect. Phenylpropanolamine was associated with increased risk for stomach and ear defects. Imidazolines, commonly found in nasal sprays, was found to increase the risk of esophagus and trachea connection abnormalities.

Researchers noted that the conditions described are extremely rare and even with an eight-fold increased risk, in some cases, the overall risk is low. According to study authors, “…baseline prevalence of endocardial cushion defect is about 0.34 per 1,000 live births…the absolute risk [after exposure to phenylephrine exposure] would be small [at] 2.7 per 1,000.”

Previous studies found an increased risk of clubfoot and facial/eye defects associated with over-the-counter decongestants, but this study showed no such risk. The real threat is in the fact that over-the-counter decongestants are widely available and do not require a prescription. Pregnant patients should never take over-the-counter medications of any kind without first consulting their attending physician or medical professional as the list of approved medications that can be safely taken during pregnancy is constantly changing.
Mitchell suggests further research be completed to pinpoint risks associated with specific ingredients in over-the-counter medications like decongestants. With additional research, a current, up-to-date list of safe medications can be developed to optimize safety during pregnancy.

Source: Wai-Ping Yau, Allen A. Mitchell, Kueiyu Joshua Lin, Martha M. Werler, Sonia Hernandez-Diaz. Use of Decongestants During Pregnancy and the Risk of Birth Defects. Am. J. Epidemiol. (2013) doi: 10.1093/aje/kws427.