The diaphragm is a barrier method of birth control. It is moderately effective, with a one-year failure rate of around 12% with typical use. It is placed over the cervix with spermicide before sex and left in place for at least six hours after sex. Fitting by a healthcare provider is generally required.

The womb veil was a 19th-century American form of barrier contraception consisting of an occlusive pessary, i.e. a device inserted into the vagina to block access of the sperm into the uterus. Made of rubber, it was a forerunner to the modern diaphragm and cervical cap. The name was first used by Edward Bliss Foote in 1863 for the device he designed and marketed. "Womb veil" became the most common 19th-century American term for similar devices, and continued to be used into the early 20th century. Womb veils were among a "range of contraceptive technology of questionable efficacy" available to American women of the 19th century, forms of which began to be advertised in the 1830s and 1840s. They could be bought widely through mail-order catalogues; when induced abortion was criminalized during the 1870s, reliance on birth control increased. Womb veils were touted as a discreet form of contraception, with one catalogue of erotic products from the 1860s promising that they could be "used by the female without danger of detection by the male."