Gräf·en·berg\ˈgref-ən-ˌberk\ , Ernst(1881–1957), American (German-born) gynecologist. Gräfenberg is credited with the introduction, in 1929, of one of the first intrauterine contraceptive devices. Consisting of a flexible ring of silver wire, it became known as the Gräfenberg ring. He first described a sensitive area of the anterior wall of the vagina in 1944. This area, now called the Grafenberg spot or G-spot, was further described in an article on the role of the urethra in female orgasm in the International Journal of Sexology in 1950.