Our friend adopted her husbands sisters daughter as our friends in early 40's had not been able to conceive, she was told to stimulate her nipples & the baby was fed formula through a tube which was strapped to her chest & the baby suckled the tube taped to her nipple, I never asked, but maybe she took drugs also, but she fed (not exclusively) there was formula top ups, but she definately had breastmilk & they did that for 8 months! (once the breasts produced milk, the tube was removed).