Can I take Mercaptopurine when pregnant or breastfeeding?
Mercaptopurine is classed as Pregnancy Category D by the FDA, which means it can potentially harm an unborn baby. Inform your doctor immediately if you are pregnant or become pregnant during treatment with Mercaptopurine. Also use an adequate form of contraception while using Mercaptopurine.
It is not yet known if Mercaptopurine passes into breast milk. Talk to your doctor before breast feeding when you are using Mercaptopurine.