Yes! It causes complications. When I was having my first child I was in a ward with a lady who got pregnant whils using a coil. It took a session in a surgery for a doctor to remove it without removing the baby. She was much distraught because, although she would have avoided pregnancy, once she was then she decided that she wanted the baby. The other question was if the baby would be affected, but they said that the worst deformity would be a hare-lip, which they could fix. We were discharged on the same day and I hope all went well for her.