Shimoni N, et al. - In this observational study, researchers investigated how early vs late menstrual cycle insertion influence bleeding/spotting in the 90 days following levonorgestrel (LNG) 13.5 mg intrauterine system (IUS) insertion. Participants (n=125) received a LNG 13.5 mg IUS and provided 90 days of bleeding/spotting data. The 90-day dichotomous analysis showed that the early and late insertion groups were not different regarding the number of days of bleeding/spotting, bleeding, or spotting. However, they noted decreased 30-day bleeding in correlation with early cycle insertion and recent hormonal contraceptive use. These findings support insertion of LNG 13.5 mg IUS throughout the menstrual cycle with small differences in bleeding patterns in the 30 but not the 90 days following insertion.