In endometriosis, tissue similar to the endometrium (the uterine lining) grows where it shouldn't — on the ovaries, the tubes, or the pelvic lining. It responds to the hormonal cycle just as the real lining does, which causes inflammation, scarring, and the condition's hallmark: periods painful enough to interfere with life. It can also cause pain during intercourse and, on the ovary, fluid-filled cysts called endometriomas ("chocolate cysts").
Endometriosis and fertility
The inflammation and scarring can distort the tubes and ovaries, and endometriomas can affect ovarian reserve. Many women with endometriosis conceive without help; for others, treatment ranges from laparoscopic surgery to IUI or IVF depending on severity, age, and reserve. Because surgery on the ovaries can itself reduce reserve, the sequencing of surgery versus IVF is an individualized decision worth discussing carefully.