Columbia subject headings:
Childbirth--Psychological aspects.
Childbirth--United States--History--20th century.
Natural childbirth--United States--History--20th century.
Pain.
Harvard subject headings:
Childbirth--Psychological aspects.
Childbirth--United States--History--20th century.
Natural childbirth--United States--History--20th century.
Pain.
Princeton subject headings:
Childbirth--Psychological aspects.
Childbirth--United States--History--20th century.
Natural childbirth--United States--History--20th century.
Pain.