We sought to determine the one-year probability of pregnancy following intended postplacental intrauterine device (IUD) insertion compared with intended insertion at a postpartum visit (interval insertion), using decision analysis methodology.METHODS:
We developed an evidence-based decision model comparing one-year probability of pregnancy following intended postplacental or intended interval IUD placement. We obtained proportion estimates from the literature for mode of delivery, successful IUD placement, IUD type, postpartum visit attendance, IUD expulsion and discontinuation, and contraceptive use, choice, and efficacy after IUD discontinuation. We performed a sensitivity analysis and a Monte Carlo simulation to account for variations in proportion estimates.RESULTS:
The one-year probabilities of pregnancy among women intending to receive a postplacental IUD following vaginal or Cesarean delivery are 94/1,000 and 68/1,000 respectively; one-year probability of pregnancy is 174/1,000 for women intending to receive an interval IUD. For interval IUD placement to have effectiveness equal to postplacental placement, 94.0% of women delivering vaginally and 97.2% of women delivering by Cesarean would need to attend postpartum care. Once placed, postplacental IUDs have effectiveness lower than interval IUDs: one-year probabilities of pregnancy following IUD placement at a vaginal delivery, Cesarean delivery, and an interval visit are 88/1,000, 51/1,000, and 24/1,000, respectively.CONCLUSION:
After accounting for barriers to successful placement and retention, intended postplacental IUD insertion results in a lower 1-year probability of pregnancy as compared with intended interval IUD insertion.