The safety and efficacy of hepatitis B virus vaccines during pregnancy has not been formally studied. However, there is no reason to suspect any risk to the fetus since both plasma-derived and genetically engineered vaccines do not contain complete or live virus (they have surface subunits only). Therefore, if a woman is clearly at risk of acquiring HBV then pregnancy should bot be a contraindication to vaccination. On the other hand, if vaccination is simply routine and part of a universal program then administration can be deferred until after delivery. DM