Short Interpregnancy Intervals in 2014: Differences by Maternal Demographic Characteristics.

KEY FINDINGS: Data from the National Vital Statistics System •Nearly 29.0% of U.S. mothers who had a second or higher-order birth in 2014 had a short interpregnancy interval of less than 18 months. •Short intervals (i.e., less than 6 months, 6-11 months, and 12-17 months) were more common for mothers aged 35 and over (5.7%, 16.3%, and 22.1%, respectively) than mothers who were under age 20 at their previous birth (5.1%, 8.8%, and 8.4%). •Short intervals of less than 6 months and 6-11 months were more common among non-Hispanic black mothers (7.1% and 11.7%, respectively) than non-Hispanic white mothers (4.1% and 11.2%) and Hispanic mothers (5.0% and 9.3%). •The percentage of births to mothers with intervals less than 6 months decreased as education level increased, from 4.3% (no high school diploma) to 1.8% (doctorate or professional degree).