Overview

The diaphragm is a birth control (contraceptive) device that prevents sperm from entering the uterus. The diaphragm is a small, reusable rubber or silicone cup with a flexible rim that covers the cervix. Before sex, the diaphragm is inserted deep into the vagina so that part of the rim fits snugly behind the pubic bone. The diaphragm is effective at preventing pregnancy only when used with spermicide.