About 18% of hysterectomies in the U.S. are performed due to endometriosis -- and it doesn't necessarily cure the problem. As many as 13% of women see their endometriosis return within three years if their ovaries are intact; the number climbs to 40% in five years. Since endometriosis often affects young women, with an average age of about 27, surgery that means no possibility of pregnancy isn't a good option for many.