Decision analysis of immediate vs. delayed insertion of intrauterine devices after abortion to prevent pregnancy

Abstract

Introduction: Immediate postabortal intrauterine device (IUD) insertion has been shown to be safe and effective, yet it is not commonly available. Materials and Methods: We performed a decision analysis to examine pregnancy rates at 1 year following abortion with immediate or delayed IUD insertion. The base case assumed an 80% 1-year continuation rate for both groups, an additional 10% expulsion risk with immediate insertion, a 30% risk for not returning for delayed insertion, and pregnancy rates of 8% without an IUD and 0.5% with an IUD. Pregnancy between abortion and delayed IUD insertion was not considered. One-way, two-way and Monte Carlo sensitivity analyses were performed. Results: In the decision model, the 12-month pregnancy rate was 20 per 1000 women in the immediate-insertion group and 33 per 1000 women in the delayed-insertion group. Sensitivity analyses show the model to be dependent on the expulsion rate in the immediate-insertion group (varied up to 30%) and the rate of not returning in the delayed-insertion group. Analysis of multiple scenarios showed that immediate insertion results in fewer pregnancies 83% of the time, with an absolute difference in pregnancy rate of 1%. If the expulsion rate is less than 10%, immediate insertion is favored in 99.5% of scenarios. Conclusion: Despite assumptions in the model heavily favoring delayed insertion, immediate postabortal IUD insertion is predicted to result in 13 fewer pregnancies per 1000 women in the following year than delayed insertion. Future research should examine cost-effectiveness and nonpregnancy outcomes.