Pregnancy and Birth Outcomes in Women with an Intrauterine Device in situ

Background: Pregnancy with an in situ intrauterine device (IUDs) is associated with increased incidence of abortion. However, if abortion does not occur, pregnancy outcomes with IUDs are not well described. Objectives: The objectives of this study is to determine the association between IUDs present during pregnancy and the occurrence of abortion (spontaneous or induced), preterm Delivery (PTD), and small for gestational age (SGA) newborns. Methods: We analyzed the National Inpatient Sample (NIS) database for the years 2010 and 2011. The NIS is a database of all-payer inpatient hospital stays collected from about 1000 hospitals across the United States from different hospital settings, care levels and diverse population. We identified the presence of an in situ IUD during delivery, spontaneous or induced abortion, PTD, and SGA using International Classification of Diseases codes (ICD-9). We used chi square and Fisher\u27s exact tests to calculate odds ratios (ORs) of abortions, PTD and SGA in women with IUDs compared to those without. We repeated the analysis using logistic regression models to control for possible confounders including maternal race, age, hypertension, diabetes, infections, obesity, smoking and many others. Results: We studied 8,597,284 maternal birth records. The prevalence of IUD in situ was 0.02%. Patients with an IUD in situ experienced greater risk for spontaneous abortion (OR= 7.2; CI: 5.1 – 10.1, p \u3c.001) and induced abortion (OR=23.1; CI: 15.6-34.4, p\u3c.001) than patients without an IUD in place. When compared to women without IUDs, women with IUDs in situ had significantly increased risk for PTD (adjusted OR=2.04; CI: 1.7-2.4, P \u3c.001) after adjusting for associated demographic and clinical variables. IUDs were not associated with increased risk to deliver SGA newborns (adjusted OR= 0.56; CI: 0.34-0.92, P = 0.022). Conclusions: Presence of an IUD in situ during pregnancy was associated with increased risk for spontaneous and induced abortions. IUDs were also associated with preterm deliveries but not with small for gestational age infants