Columbia subject headings:
Childbirth--United States--History.
Maternal health services--United States--History.
Obstetrics--Social aspects--United States.
Obstetrics--United States--History.
Harvard subject headings:
Childbirth--United States--History.
Maternal health services--United States--History.
Obstetrics--Social aspects--United States--History.
Obstetrics--United States--History.
Princeton subject headings:
Childbirth--United States--History.
Maternal health services--United States--History.
Obstetrics--Social aspects--United States--History.
Obstetrics--United States--History.