<<A friend of mine, breastfeeding a 2 years old toddler, has suffered two
consecutive miscarriages. Her obstetrician is not sure if bf has a
relationship; but anyway she has decided to wait until complete weaning
before trying again.>>

Although breastfeeding is probably not the problem, more than two spontaneous
miscarriages may be related to antibodies in the mother's system. She might
want to be checked for antiphospholipid antibodies, specifically
anticardiolipin antibody.  This can cause spontaneous abortion and
unexplained stillbirth due to interference with placental development and
function.
Elaine Lukasavitz, CNM.