Postpartum Levonorgestrel-releasing Intrauterine System and Breastfeeding

1. Women ages 18-45 2. Pregnant and equal to or more than 24 weeks of estimated gestational age 3. States an intent to breastfeed for at least 6 months 4. States a plan to use the LNG-IUS postpartum 5. Anticipates a vaginal delivery 6. HIV negative 7. Intend to stay in the Chapel Hill area for at least 6 months after birth 8. No medical or personal conditions which in the judgment of study staff preclude participation in the study 9. Have no allergies to any component of the LNG-IUS 10. No known uterine anomalies 11. Fluent in English 12. No history of ectopic pregnancy 13. No known or suspected carcinoma of the breast 14. No known acute liver disease or liver tumor (benign or malignant) 15. No known or suspected uterine or cervical neoplasia or unresolved abnormal pap smear 16. No active pelvic inflammatory disease 17. No known hypersensitivity to any component of the LNG-IUS 18. No genital bleeding of unknown etiology 19. No history of solid organ transplantation Additional eligibility criteria for entry into the randomized trial, as assessed postpartum 1. No endometritis or chorioamnionitis 2. Membranes ruptured for less than 24 hours prior to delivery (O'Hanley, Hayes) 3. No fever greater than or equal to 38°C during the intrapartum or postpartum period 4. Did not receive medications other than pitocin and/or misoprostol to control postpartum bleeding 5. Did not have a documented estimated blood loss of greater than 750mL intrapartum 6. Did not receive a blood transfusion for a diagnosis of postpartum hemorrhage 7. Did not have a third or fourth degree laceration at delivery. 8. The infant must be greater than 35 weeks EGA at birth as determined by physical exam at birth 9. The infant must weigh at least 2727 grams 10. Must have been a singleton birth 11. Infant not in the intensive care nursery 12. The infant has not been diagnosed with a condition which would preclude long term feeding