It is not patently obvious that this medication is contraindicated during breastfeeding.  Azathioprine
is an antimetabolite, and can have serious side effects.  The amount that gets into the milk, however,
is very low.  Presumably, from what you have said, the mother has been on it during pregnancy.
This may be unavoidable, but it remains that the baby is likely to have had much greater effects in
utero than if the mother breastfed.

In addition, everything has to be taken into consideration, including the risks of formula for mother
and baby, and the mothers desires in all this.  It cannot be assumed that breastfeeding is
automatically contraindicated.

This is a tough one.  But the mother, and father, have the right to make the final decision.  Not us.

Jack Newman, MD, FRCPC