Complications after interval postpartum intrauterine device insertion

Background: In the United States, up to 57% of women report resumption of sexual activity by the 6 week postpartum visit. Effective contraception should be addressed and provided at that time, to avoid unintended pregnancies and optimize interpregnancy intervals. Long-acting reversible contraceptives are the most effective forms of reversible contraception and are increasingly popular during the postpartum period. However, timing of postpartum intrauterine device (IUD) placement varies among providers and many delay insertion due to concerns for uterine perforation or expulsion of the IUD.

Objective: This study aimed to evaluate uterine perforation and expulsion rates with IUD insertion at 4-8 weeks postpartum vs 9-36 weeks postpartum.

Study design: We performed a retrospective cohort study using the Kaiser Permanente Southern California electronic medical record from 2010 to 2016. We calculated the proportion of perforations and expulsions with IUD insertion at 4-8 weeks vs 9-36 weeks postpartum. Our primary outcome was the perforation rate. Secondarily, we evaluated the expulsion rate. For our minimum sample size calculation, to detect a difference of 0.5% in the perforation rate, with a baseline perforation rate of 0.5% for the 9-36 week postpartum IUD placement group, 80% power, and 5% alpha error rate, we would need at least 4221 participants per group, 8442 in total.

Results: A total of 24,959 patients met inclusion criteria (n=13,180 in the 4-8 week group, n=11,777 in the 9-36 week group). Of 430 patients with a confirmed complication, 157 uterine perforations and 273 IUD expulsions were identified. Perforation rates were significantly higher with placement at 4-8 weeks than at 9-36 weeks (0.78% vs 0.46%; P=.001). After adjusting for race and ethnicity, breastfeeding, IUD type, provider type, parity, most recent delivery, and body mass index, the odds of perforation remained higher with placement at 4-8 weeks than at 9-36 weeks (adjusted odds ratio, 1.92; 95% confidence interval, 1.28-2.89). Our Kaplan-Meier survival curve showed that the risk of uterine perforation remained elevated until approximately 22-23 weeks postpartum. Expulsion rates were similar between the 2 groups (1.02 vs 1.17; P=.52).

Conclusion: Uterine perforation after interval postpartum IUD insertion is greater at 4-8 weeks than at 9-36 weeks, although perforation rates remain low at <1%. Expulsion rates did not differ between the groups. Because overall rates of uterine perforation are low, women can safely be offered IUDs at any interval beyond 4 weeks with minimal concern for perforation.