Maternal death rates began to plummet when germ theory became more widely accepted, I believe, but that was prior to industrialized medicine. Hospital births (which had a slightly negative impact on maternal and infant survival) didn't begin to be standardized until the 20th century, though of course I suppose it depends on how you define the start of industrialized medicine.

God I am really just talking out my ass here. Any history of medicine scholars in the house? There's got to be a book on this.