Abstract
PURPOSE: The purpose of the article was to determine risk factors associated with interpregnancy interval (IPI) and how IPI is associated with subsequent pregnancy outcomes. METHODS: We performed bivariate and multivariable analyses of the Colorado Birth Certificate Registry data from women with a last live birth from 2004 to 2013, among Coloradan women aged 19 years and younger. RESULTS: Our multivariate analysis found that older adolescents aged 17-19 years had a reduced likelihood of an IPI >18 months (odds ratio [OR] .8; confidence interval [CI] .7-.9). Self-identifying as Hispanic increased the likelihood of an IPI <18 months, whereas delivering during or after 2009 or having Medicaid insurance significantly increased the odds that an adolescent would have an IPI >18 months (OR 1.5 [CI: 1.4-1.6]; OR 1.2 [CI: 1.1-1.2]; OR 1.5 [CI: 1.4-1.6], respectively). We found that an IPI >18 months was associated with the following dependent variables in unique logistic regressions adjusted for age, ethnicity, year of last live birth, and insurance status: reduced risk of neonatal complications (OR .9 [CI: .8-.9]), reduced risk of overweight/obesity (OR .9 [CI: .8-.9]), and an increased likelihood of normal birthweight (OR 1.2 [CI: 1.1-1.4]), term birth (OR 1.3 [CI: 1.1-1.4]), and attending 14 or more prenatal visits (OR 1.3 [CI: 1.2-1.4]. CONCLUSIONS: Having an IPI >18 months in adolescent Coloradan women is associated with an increased likelihood of prenatal care attendance, term birth, and normal birthweight and with a reduced likelihood of neonatal complications.