👉 A knockup is a medical procedure in which a woman's ovaries are surgically removed, typically after ovulation has occurred. This involves removing all of the follicles from her uterus and replacing them with healthy, mature eggs or sperm. The purpose of this procedure is to prevent pregnancy by preventing the development of the egg or sperm in the fallopian tubes. Knockups have been used as a treatment option for various fertility issues such as endometriosis, polycystic ovary