Considered one of the most effective forms of reversible birth control[15] Can be used while breastfeeding[16] (see also nursing mothers) No preparations needed before sex,[17] though routine checking of the device strings by patient and physician is advised to ensure proper placement remains intact[18] 90% of users who wish to become pregnant do so within 24 months of removal.[19] May experience lighter periods (some women stop having periods completely, see also amenorrhea)[20] Effective for up to three to five years (depending on the IUD)[21]