In the early 19th century, gynecologists would treat women by placing leeches "on the vulva or neck of the uterus," and some "adventurous" leeches would "advance into the cervical cavity of the uterus itself," causing the woman terrible pain.
Info Source: Wood, Ann Douglas. "The Fashionable Diseases." Journal of Interdisciplinary History. 4.1 (Summer, 1973). Thanks to (WinniethePooja)