When I had my last son, my obgyn did not inform me any negative side effects. I had previously used the copper T, and although I still got my period, mine aren't that bad, but still, my Ob-gyn assured my the progesterone in the Mirena would be limited to that area. Well 3 years later and I have had headaches, never got my libido back (which is hard on a marriage), and have gain about 30 pounds(with no change in diet or activity) from my 6 week post delivery check-up. I only have short spotting with Mirena, but would trade for a monthly period in a heartbeat if I could go back to my post pregnancy weight of 116 and get libido back. It was not until my check-up last week that I was informed it could affect libido. I'm 5'2", so 30+ pounds really shows, my mother and mother-in-law, both had made comments about "hoping I wasn't pregnant again. Its also caused a loss of self esteem and depression over all this. If my insurance will cover it I plan to go back to my old, 10-year copper IUD.