For women who have already had children and do not want to have children at the moment, they can often consider placing an intrauterine device for contraception. This is because the IUD is a foreign body in the uterine cavity and can affect the fertilization of the egg, as well as the entry of sperm and even the killing of sperm, so that it can be used as a contraceptive. However, it is not true that all women will not get pregnant after having an IUD. This is because after having an IUD, if the ring moves down or falls off, it may lead to conception with the ring, and conception with the ring is mostly ectopic pregnancy, because the ring affects the fertilized egg’s implantation in the uterine cavity, and then the fertilized egg may implant in other places outside the uterine cavity, resulting in ectopic pregnancy. However, in a very small percentage of women, the fertilized egg will be laid in the upper part of the uterine cavity after the ring has moved down, resulting in an intrauterine pregnancy with the ring. Whether the pregnancy is intrauterine or ectopic with the ring, the pregnancy often cannot continue and must be terminated. In the case of ectopic pregnancy caused by the IUD, laparoscopic surgery is often required and the ring has to be removed. In conclusion, no method of contraception is 100% effective. The IUD is very effective, but there is still a possibility of pregnancy with the device.