Characteristics and outcomes of pregnancy with retained intra-uterine device

Abstract

To describe characteristics and outcomes of pregnancy with retained intra-uterine device (IUD). The Healthcare Cost and Utilization Project’s National Inpatient Sample was retrospectively queried. The study population was 14,648,135 deliveries from January 2016 to December 2019. The exposure assignment was per retained IUD status, identified according to the World Health Organization’s International Classification of Disease 10th revision of O26.3. A multivariable binary logistic regression model was used to identify the independent characteristics related to retained IUD. Retained IUD was reported in one in 8,161 patients. Pregnancies with retained IUD were associated with increased risk of preterm premature rupture of membranes (9.5% versus 2.7%), placental abruption (3.6% versus 1.1%), placenta accreta spectrum (0.8% versus 0.1%), fetal anomaly (2.8% vs 1.1%), extremely preterm delivery at < 28 weeks (8.1% versus 1.1%), and early preterm delivery between 28-31 weeks (4.2% versus 0.9%) in a multivariable analysis (all, adjusted-P < 0.05). Patients in the retained IUD group were also associated with high-risk pregnancy profiles including advanced maternal age (21.7% versus 17.8%) and obesity (14.2% versus 10.9%) in a multivariable analysis (both, adjusted-P < 0.05). Last, although it did not maintain independent association in multivariable analysis, intrauterine fetal demise occurred more in the retained IUD pregnancy group (3.3% vs 0.8%; P < 0.001 in univariable analysis). Retained IUD in pregnancy was not associated with intrauterine growth restriction (3.9% versus 3.5%, P = 0.347). The current nationwide analysis suggests that while pregnancy with retained IUD is rare, these pregnancies may be associated with high-risk pregnancy characteristics and outcomes.