This part of algorithm outlines the insertion procedures of Mirena. Mirena should be inserted by a well-trained doctor who is familiar with insertion instructions. The best time for insertion is any of the seven days during the onset of menstruation, or right after first trimester post abortion/miscarriage because the uterine lining is thinned and the patient is at no risk of being pregnant. In addition, during menstrual period, the cervix is dilated and it is easier to insert Mirena. 

Prior to the insertion, medical tests are needed for excluding contraindications to the use of Mirena. The tests may include a urine pregnancy test, a lithotomy position, and a bimanual exam. After thorough cleansing, the patient should also prepare for sounding the uterine cavity. The uterine sound is used for checking the patency of the cervix and measuring the depth of the uterine cavity. Ideal sounded depth is 6 to 10 cm, otherwise insertion may cause expulsion, bleeding, pain, perforation, and pregnancy. To begin inserting, the doctor needs to load Mirena into an insertion tube, and set the flange according to the uterine depth measured during uterine sound. The doctor will advance the insertion tube into the uterine cavity and keep 1.5 to 2 cm length of the flange from the external cervical os so that enough space is left for the arms to open within the uterine cavity. After the doctor releases the arms of Mirena, the inserter needs to be advanced to fundal position. The patient can inform doctor to release Mirena from the inserter once she feels fundal resistance. After the doctor withdraws the inserter and cuts the threads of Mirena, the Mirena insertion is completed.