placenta praevia
Concise Oxford English Dictionary © 2008 Oxford University Press:
placenta praevia /ˈpriːvɪə/ (US placenta previa)
▶noun Medicine a condition in which the placenta partially or wholly blocks the neck of the uterus, so interfering with normal delivery of a baby.
– origin C19: from L. praevia ‘going before’, fem. of praevius.
'placenta praevia' also found in these Oxford entries:

