What Are the Risks of Taking Prednisone in Pregnancy?

Prednisone is a corticosteroid that is often prescribed to treat inflammation, but it is generally not recommended for pregnant women unless there are no alternate medications available. While it has not been officially assigned to a category by the U.S. Food and Drug Administration (FDA), most sources list it as category B or C, meaning it may pose a danger to the fetus. The most common risks of this drug include cleft palate or lip, low birth weight and premature birth. Conflicting reports of prednisone in pregnancy have resulted in it being advised that pregnant patients only use this drug when no other anti-inflammatory medication will treat their condition.

While the FDA has not formally categorized prednisone, its active ingredient, prednisolone, has been assigned to category C. In small studies, it has been shown to result in cleft palate or lip, along with other birth defects. Premature delivery and low birth weight are also suggested to have occurred when mothers took this drug in the first trimester. These studies were small, however, and did not provide enough controls to determine whether the birth defects were truly caused by the prednisone instead of an underlying condition. For this reason, prednisone in pregnancy is only classed as a category C drug according to some sources.

The fact that the only studies of prednisone in pregnancy involving humans were not scientific means this drug also is sometimes put into category B. Medications in this category are often considered safe to take in moderation because studies in either animals or humans have shown no ill effects. Unlike category A drugs, which are considered perfectly safe to take during pregnancy, medications in category B are only to be used in moderation. In general, women are advised to use prednisone in pregnancy only when necessary, such as when the positive effects outweigh the slim possibility of birth defects. When safer medications can obtain the same results as prednisone, though, pregnant women are advised to take those instead.

Taking prednisone while breastfeeding is considered slightly safer than taking prednisone in pregnancy, because only a small percentage of the drug transfers to breast milk. To be on the safe side, nursing mothers are advised to take the lowest dose possible while still treating their condition. When high doses are necessary, nursing mothers are advised to wait to breastfeed at least four hours after taking the drug.