The main contraceptive principle is to change the thickness of the endometrium in order to reduce the symptoms of excessive menstruation, or dysmenorrhea. Therefore, irregular menstruation and irregular vaginal bleeding may occur when the Mannorrhoea IUD is placed, which will usually turn to normal after about 3 months. If the condition persists for more than 3 months and the symptomatic treatment does not improve, it is recommended to remove the IUD. The IUD can be replaced once every 5 years, so if you wish to get pregnant while using the IUD, you can remove it at any time.