Some of the ingredients in cold medications are considered safe for pregnant women, but others should be avoided.
Most cold medicines are multi-symptom remedies that contain two or more drugs (although you can also buy these drugs individually). The drugs include antihistamines for alleviating allergy symptoms and helping you sleep, antitussives for suppressing coughs, expectorants for loosening up mucus, decongestants for relieving stuffiness, and analgesics for easing aches and pains.
Remember that no drug is 100 percent safe for all women, so it's a good idea to check with your doctor or midwife before taking any kind of medicine during pregnancy. Don't take more than the recommended dose and, if possible, avoid taking anything during your first trimester, when your developing baby is most vulnerable.
Here are a few cold medications that are okay to take during pregnancy:
The antihistamines chlorpheniramine, loratadine, doxylamine, brompheniramine, phenindamine, pheniramine, triprolidine, and diphenhydramine are considered low risk during pregnancy, but they can make you sleepy, especially doxylamine and diphenhydramine.
The expectorant guaifenesin thins mucous secretions in the respiratory passages, making it easier to cough them up. While one study found an increased risk of inguinal hernias in babies exposed to this drug, others have not. Although avoiding any drug in pregnancy is the safest course, exposure to guaifenesin does not appear to cause harm to a developing baby.
The cough suppressant dextromethorphan got some bad press after one study found that it caused birth defects in chick embryos, but this study had many flaws. Other good studies of women who took the drug during pregnancy have found that it doesn't raise the risk of birth defects in humans.
The local anesthetic benzocaine is combined with dextromethorphan in one product to treat sore throats. Benzocaine doesn't get into the bloodstream, so it doesn't pose a risk to a developing baby.
The pain reliever and fever reducer acetaminophen has been well studied. It's considered safe to take during pregnancy as long as you take no more than the dose recommended on the label.
Here are some cold medications to avoid:
It's best to avoid the decongestants pseudoephedrine and phenylephrine, especially in the first 13 weeks of pregnancy, since there have been some reports of related birth defects. Although the risk appears to be low, it could be higher if you're a smoker. After the first trimester, occasional use of these medications (for example, once or twice daily for no more than a day or two) is probably safe. More frequent use, however, can reduce blood flow to the placenta.
You'll also need to avoid the pain relievers aspirin, ibuprofen, naproxen, sodium salicylate, and other nonsteroidal anti-inflammatory drugs (NSAIDs), especially in the third trimester.
One final caution: Some liquid cold medicines contain alcohol in concentrations as high as 4.75 percent. Look for products that are labeled "alcohol-free."
Read more about over-the-counter medications during pregnancy.
Erebara A, et al. 2008. Treating the common cold during pregnancy. Canadian Family Physician h54(5):687-9. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2377219/ [Accessed June 2016]
Mayo Clinic. 2014. Drugs and supplements, cough and cold combinations (oral route): Pregnancy. http://www.mayoclinic.org/drugs-supplements/cough-and-cold-combinations-oral-route/before-using/drg-20061164
Medscape. 2013. Drugs in pregnancy. http://www.medscape.com/viewarticle/813743_3
Silva R, et al. 2007. Clinical inquiries. Is guaifenesin safe during pregnancy? Journal of Family Practice 56(8):669-70. http://www.ncbi.nlm.nih.gov/pubmed/17669294 [Accessed June 2016]
Wigle PR, et al. 2006. Pregnancy and OTC cough, cold, and analgesic preparations. US Pharmacist 3:33-47. http://www.uspharmacist.com/content/d/featured_articles/c/11693/ [Accessed June 2016]
UpToDate. 2014. Treatment of respiratory infections in pregnant women. http://www.uptodate.com/contents/treatment-of-respiratory-infections-in-pregnant-women?source=search_result&search=cold+treatment+pregnancy&selectedTitle=1~115#H6