contraceptive diaphragm, a contraceptive device consisting of a hemisphere of thin rubber bonded to a flexible ring, inserted into the vagina together with spermicidal jelly or cream up to 2 hours before coitus. Fitted between the pubic symphysis and the posterior fornix of the vagina, the diaphragm cups the cervix in a pool of spermicide so that spermatozoa encounter a physical barrier, thus preventing conception. The rate of failure of the diaphragm method of contraception is approximately 2 unplanned pregnancies in 100 women using the method properly for 1 year. The principal advantage of the diaphragm is that it has no systemic effects. Diaphragms are manufactured in seven standard sizes from 55 to 100 mm in diameter. Also called diaphragm. Kinds include arcing spring contraceptive diaphragm, coil spring contraceptive diaphragm, flat spring contraceptive diaphragm.
