Warfarin has been shown to cause birth defects in the first trimester of pregnancy so must be avoided early in pregnancy. In some women, it may be used later in pregnancy, however alternate anti-clotting medication is usually prescribed during pregnancy, such as heparin injections. It is important that you do not become pregnant while taking warfarin. If you wish to become pregnant you should discuss this with your doctor first. There are other options available. They will decide what alternative option is best for your situation.

Should you become pregnant while taking warfarin you should notify your doctor as soon as possible.

Although warfarin must be avoided during pregnancy, it is safe to take warfarin while breastfeeding. This is because very little of the medication gets into the breast milk, and is unable to affect your baby.