Adolescent Interpregnancy Interval in Colorado Among Women With a Last Live Birth Between 2004 and 2013

The purpose of the article was to determine risk factors associated with interpregnancy interval (IPI) and how IPI is associated with subsequent pregnancy outcomes.

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.

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].

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.