Last fall I had a client who never produced more than about an ounce a day.
She'd had hyperprolactinemia that was controlled by bromocriptine in order
to get pregnant, and she was on thyroid meds.

I think I finally found the reason for her low supply.  During pregnancy,
her prolactin level was tested once and found to be normal... for a
non-pregnant woman.  That fact was brushed off by her endocrinologist, and
I didn't pick up on it either.  But since prolactin (which should
ultimately increase by 20x or so) is needed for full breast development
during pg, I'm guessing that, although her breasts enlarged some, she just
never really finished the job during pregnancy and didn't have enough
alveoli/ducts to work with postpartum.

Had she persisted, maybe she could have increased her milk supply somewhat
the way an adoptive mom does:  by building breast tissue thru the influence
of nipple stimulation alone.

And speaking of prolactin, given the very high levels of prolactin in late
pregnancy, shouldn't moms who get migraines as a result of prolactin be
getting horrific headaches in late pregnancy?

Diane Wiessinger, MS, IBCLC, LLLL  Ithaca, NY