OBJECTIVE: The APEX-IUD study evaluated the association of postpartum timing of intrauterine device (IUD) insertion, breastfeeding, heavy menstrual bleeding (HMB), and IUD type (levonorgestrel-releasing vs. copper) with risks of uterine perforation and IUD expulsion in usual clinical practice. We summarize the clinically important findings to inform counseling and shared decision-making.
METHODS: APEX-IUD was a real-world (using US healthcare data) retrospective cohort study of individuals aged ≤50 years with IUD insertions between 2001 and 2018 and with electronic health record data. Cumulative incidences of uterine perforation and IUD expulsion were calculated. Adjusted hazard ratios (aHRs) and 95% CIs were estimated from proportional hazards models with control of confounding.
RESULTS: Among the study population of 326,658, the absolute risk of uterine perforation was low overall but was elevated for IUD insertions within a year postpartum, and particularly among those between 4 days and 6 weeks postpartum (aHR=6.71, 95% CI=4.80-9.38), relative to nonpostpartum insertions. Among postpartum insertions, IUD expulsion risk was greatest for insertions in the immediate postpartum period (0-3 days after delivery) versus nonpostpartum (aHR=5.34, 95% CI=4.47-6.39). Postpartum individuals who were breastfeeding had a slightly elevated risk of perforation and lowered risk of expulsion than those not breastfeeding. Among nonpostpartum individuals, those with an HMB diagnosis were at greater risk of expulsion than those without (aHR=2.84, 95% CI=2.66-3.03); HMB was also associated with a slightly elevated perforation risk. There was a slightly elevated perforation risk and slightly lower expulsion risk associated with levonorgestrel-releasing IUDs versus copper IUDs.
CONCLUSION: Absolute risk of adverse outcomes with IUD insertion is low. Clinicians should be aware of the differences in risks of uterine perforation and expulsion associated with IUD insertion during specific postpartum time periods and with an HMB diagnosis. This information should be incorporated into counseling and decision-making for patients considering IUD insertion.
