Dear Jo

I know only one study about the passage in milk of methotrexate. The mother
was taking 22,5 mg/day for a cancer. The maximum level in milk was 2,7 µg/l,
with a ratio milk/plasma of 0,08. So, methotrexate passes very very few in
breast mil. It is told here than when a mother takes methotrexate in little
doses, she can breastfeed. Better to look at the baby (hematology), and give
folic acid to the baby and to the mother (done systematically for the
mother).

Hope this help
Françoise Railhet
LLL France Medical Associates Program