| ||Maternal age is a risk factor for preterm birth, with higher preterm birth rates found among the youngest and oldest mothers in the U.S. |
| ||During 2008-2010 (average) in Chicago, late preterm birth rates were highest for women ages 40 and older (12.8%), followed by women under age 20 (10.0%), ages 20-29 (9.0%) and ages 30-39 (8.6%). |
| ||Of all infants born during 2008-2010 (average), 12.1% were to mothers under the age of 20, 46.1% were to mothers ages 20-29 years, 38.5% were to mothers ages 30-39 years, and 3.3% were to mothers ages 40 and older. |
National Center for Health Statistics, final natality data.
Retrieved June 19, 2013, from www.marchofdimes.com/peristats.