TY - JOUR T1 - Does antiviral medication for treating herpes simplex during pregnancy increase the risk of birth defects in offspring? JF - Evidence Based Medicine JO - Evid Based Med SP - 30 LP - 30 DO - 10.1136/ebm1157 VL - 16 IS - 1 AU - De-Kun Li Y1 - 2011/02/01 UR - http://ebm.bmj.com/content/16/1/30.abstract N2 - Commentary on: Pasternak B, Hviid A. Use of acyclovir, valacyclovir, and famciclovir in the first trimester of pregnancy and the risk of birth defects. JAMA. 2010;304:859–66.OpenUrlCrossRefPubMed The teratogenic effect of antiviral medication use during pregnancy has not been well evaluated in the human population. Among the currently used antiviral medications, those used to treat herpes simplex such as acyclovir, valacyclovir and famciclovir are most common, although overall usage of antiviral medication in pregnant women remains low. This was a data linkage study based on Danish national registries for both prescription drugs and birth defects registration data. Despite a study period covering close to 13 years of data with 837 795 births, only 1804 pregnant women used any of these three antiviral medications during the first trimester, an exposure frequency of 2/1000. Any … ER -