'amniocentesis' originates from Greek, specifically the words 'amnion' meaning 'membrane around the fetus' and 'kentesis' meaning 'pricking' or 'puncture.'

'amniocentesis' was formed in modern medical English by combining the Greek roots 'amnion' and 'kentesis' to describe the procedure of puncturing the amniotic sac.

Initially, it referred specifically to the act of puncturing the amniotic sac, but now it is used to describe the medical procedure for extracting amniotic fluid for testing.