The O-ring is a kind of birth control ring shaped like the letter O, belonging to the metal ring, which is a simple, safe and effective contraceptive device.The O-ring is a kind of traditional birth control ring, which can be placed in a woman’s uterus until amenorrhea, and it is more convenient to wear it and the price is more moderate, which doesn’t affect the whole body’s function, and doesn’t influence the sex life either. However, the disadvantage is that for some people it is easy to embedded not secure, so before wearing the IUD must first do a checkup to understand their own physical condition, wear it to pay attention to the size of the IUD and the uterine cavity to match, to avoid because of the IUD downward or out of the ring, and lead to unwanted pregnancy. In addition, the best time to place the IUD is within 3-7 days after the menstrual period is cleared. Sexual intercourse should be prohibited for 2 weeks after the IUD is placed, and the position of the IUD should be rechecked after the menstrual period is cleared to make sure that it is in a normal position. 3-6 months after the IUD is placed, there may be symptoms of increased menstrual flow and lower abdominal pain, if rest does not alleviate the symptoms, you need to follow the doctor’s instructions to take medication to stop bleeding for relief.