Side effects include irregular periods, benign ovarian cysts, pelvic pain, and depression.[2] Rarely uterine perforation may occur.[2] Use is not recommended during pregnancy but is safe with breastfeeding.[2] The IUD with progestogen is a type of long-acting reversible birth control.[4] It works by making the mucus at the opening to the cervix thick, stopping the buildup of the lining of the uterus, and occasionally preventing ovulation.[2]