Contraindications include the following: Anatomic abnormalities that distort the uterine cavity Current pelvic infection, usually pelvic inflammatory disease (PID), mucopurulent cervicitis with a suspected STI, pelvic tuberculosis, septic abortion, or puerperal endometritis or sepsis within the past 3 months Unexplained vaginal bleeding Pregnancy Gestational trophoblastic disease with persistently elevated serum beta - human chorionic gonadotropin (beta-hCG) levels (a relative contraindication because supporting data are lacking) Known cervical cancer or endometrial cancer For levonorgestrel - releasing IUDs, breast cancer or allergy to levonorgestrel For copper - bearing T380 IUDs, Wilson disease or allergy to copper Conditions that do not contraindicate IUDs include the following: Contraindications to contraceptives that contain estrogen (eg, history of venous thromboembolism, smoking > 15 cigarettes / day in women > 35, migraine with aura, migraine of any type in women > 35) A history of PID, STIs, or ectopic pregnancy Breastfeeding Adolescence The patient's personal beliefs about abortion because IUDs are not abortifacients (however, a copper or 52-mg levonorgestrel - releasing IUD used for emergency contraception may prevent implantation of the blastocyst, possibly terminating a viable pregnancy) Adverse effects Vaginal bleeding is often irregular in the first several months after insertion of a levonorgestrel - releasing IUD.