Which of the following is a risk factor for endometriosis?

• A. Late menarche
• B. Early menarche
• C. Retroverted uterus
• D. Family history

Answer: (B)

Early onset of menstruation increases a person’s lifetime estrogen exposure and the number of menstrual cycles. This extends the window during which endometrial tissue can shed and retrograde flow can seed ectopic cells in the pelvic cavity. The more cycles and estrogen exposure, the greater the chance that endometrial tissue implants outside the uterus and grows, leading to endometriosis. So starting periods earlier is a recognized risk factor. Late menarche would shorten exposure and reduce risk. A retroverted uterus isn’t a firmly established risk factor, and family history can be associated with risk, but the clearest and most consistent factor among the options is early menarche.