title: Contraceptive effectiveness of immediate compared with delayed insertion of intrauterine devices after abortion: a decision analysis.
abstract: OBJECTIVE
  To model rates of pregnancy and repeat abortion among women choosing intrauterine contraception after an abortion when the intrauterine device (IUD) is inserted immediately after the procedure or at a follow-up visit.
  
  
  METHODS
  We created an evidence-based decision model of women desiring to avoid pregnancy for the 12 months after an abortion. Base case assumptions were pregnancy rates of 0.5% with an IUD and 20% without an IUD, 1-year IUD continuation rate of 80%, an additional 5% risk of IUD expulsion with immediate insertion, and a 35% risk of not returning for a follow-up visit for IUD insertion. Sensitivity analyses and Monte Carlo simulation were performed.
  
  
  RESULTS
  Immediate IUD insertion after abortion prevented 52 pregnancies over the following year for every 1,000 women modeled by using base case assumptions. Sensitivity analyses show the model to be most dependent on the rate of expulsion in the immediate-insertion group and the proportion not returning in the delayed-insertion group. Monte Carlo analysis showed that immediate insertion resulted in fewer pregnancies than delayed insertion in 91% of scenarios, with an absolute mean difference of 28 pregnancies per 1,000 women in the initial year after abortion. If 20% of U.S. women undergoing abortion opted for immediate insertion, an estimated 20,000 repeat abortions would be prevented in the first year.
  
  
  CONCLUSIONS
  Women who have an IUD inserted immediately after an abortion are expected to have fewer pregnancies and repeat abortions than women scheduled for insertion of an IUD at a follow-up visit.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine and the Magee-Womens Research Institute, Pittsburgh, Pennsylvania 15213-3180, USA mreeves@magee.edu
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Reeves
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Smith
authors.forename: Mitchell D
authors.initials: MD
authors.lastname: Creinin
mesh_terms: D000028:Abortion, Induced / Q000706:statistics & numerical data*; D000328:Adult; D003657:Decision Making; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007433:Intrauterine Device Expulsion; D007434:Intrauterine Devices / Q000592:standards / Q000706:statistics & numerical data; D009010:Monte Carlo Method; D011184:Postoperative Period; D011247:Pregnancy; D018873:Pregnancy Rate; D011275:Pregnancy, Unwanted; D012307:Risk Factors; D013997:Time Factors