Kelley's infertility is caused by blocked fallopian tubes. she has no history of pelvic infections or sexually transmitted infections. what is the most likely cause of the blockage?

One of the most common causes of blocked fallopian tubes is endometriosis (after pelvic inflammatory disease and sexually transmitted diseases). Uterine infection caused by an abortion or abdominal surgery can also cause blocked fallopian tubes. If fallopian tubes are blocked, the egg can't reach the uterus, and the sperm can't reach the egg which prevents fertilization and pregnancy.