To determine whether the increase in the rate of labor induction at term is significantly different among women of different races.
Data from the National Center for Health Statistics were used to identify pregnant women with singletons at 37–41 weeks gestation from 1991 to 2003 in Illinois. The independent association between the induction rate at term and maternal race was evaluated using longitudinal regression. Covariates considered were maternal demographic and obstetrical characteristics; those that changed the estimated association between race and induction of labor
by at least 20% were included in the final model.
The mean annual induction rates rose significantly during the study period both for the entire population and for each racial group. After adjusting for maternal demographic characteristics, obstetrical risk factors for medically-indicated induction, and for county-level malpractice premium charges, each 1% increase in the proportion of the white and non-white/non-African American populations within a county was associated with significantly higher induction rates (74% and 92%, respectively) in the county.
Although induction rates have increased for all women, the rate of rise has increased disproportionately among women of non-African American race.