The term intrauterine refers to occurrences within the uterus. However, since the uterus has a cavity that is accessible through the cervix, the term is often used to mean "within the uterine cavity." Thus, intrauterine development refers to development of the embryo within the uterus (both before and after implantation), while an intrauterine device (IUD) is a contraceptive device inserted into the uterine cavity.