What are the disadvantages of Mirena® as a method of contraception? Insertion and removal of the device requires a procedure that is a little uncomfortable and can only be performed by a trained doctor or nurse after the insertion there may be irregular light spotting for 2 weeks to 6 months while the IUD settles in. After this most women have light regular periods, no periods, or infrequent bleeding. Uncommonly, the bleeding may be unacceptable to some women Does not protect against sexually transmitted infections (STIs)