Final answer:
The diaphragm is a birth control device that is placed surrounding the cervix to prevent sperm from entering the uterus. It requires correct placement and use for effectiveness and should be used in conjunction with spermicide.
Step-by-step explanation:
The diaphragm, a form of female birth control barrier, is placed surrounding the opening of the cervix. The diaphragm is a flexible cup that is inserted vaginally before sexual intercourse and functions by covering the cervix to block sperm from entering the cervical canal and the uterus. To enhance effectiveness against pregnancy, it is recommended that the diaphragm be used with spermicide. After intercourse, the diaphragm should be left in place for at least six hours to ensure its contraceptive effectiveness. While it helps to prevent pregnancy, it must be noted that the diaphragm does not prevent the spread of sexually transmitted infections (STIs) and may lead to an increase in urinary tract infections when used.