The most suitable time for IUD placement is within 3-7 days after menstruation. 1. 3-7 days after menstruation, the ovaries have not yet started ovulation, so there is no possibility of pregnancy after IUD placement. 2. 3-7 days after menstruation, the cervical area is soft and the cervical opening is loose, so it is easy to enter the uterine cavity during IUD placement and reduce the pain caused by IUD placement. 3, before the preparation of the IUD within 3 days before sex can not occur. After the IUD is placed, you should take proper rest, no strenuous exercise and heavy physical labor for a short time, and no sexual intercourse within two weeks. The first 3 months after IUD placement should be reviewed regularly to avoid displacement of the IUD.