obstetrics
Concise Oxford English Dictionary © 2008 Oxford University Press:
obstetric/əbˈstetrɪk/
▶adjective relating to childbirth and the processes associated with it.
– derivatives
obstetrical adjective (chiefly N. Amer.),
obstetrically adverb,
obstetrics plural noun.
obstetrical adjective (chiefly N. Amer.),
obstetrically adverb,
obstetrics plural noun.
– origin C18: from mod. L. obstetricus from L. obstetricius (based on obstetrix ‘midwife’), from obstare ‘be present’.
'obstetrics' also found in these Oxford entries:

