PRETERM BIRTHS

This indicator reports the percentage of total annual births which are preterm. Preterm birth is defined as the delivery of an infant at less than 37 weeks of gestation, the period of time between conception and birth. Late preterm births (occurring between 34 to 36 weeks of gestation), moderate preterm births (occurring between 32 to 33 weeks of gestation), and very preterm births (occurring less than 32 weeks of gestation) are subsets of preterm births. Since 2014, preterm births have been calculated by establishing the gestational age based on the obstetric estimate. For years 2013 and earlier, the gestational age was calculated in the month prenatal care began by recording the date of the last normal menses. This change may lead to a slight discontinuity in prenatal care results between years 2013 and 2014.

Preterm birth is an important public health issue requiring sustained focus on its causes, consequences, and prevention strategies.1 Several factors – economic, personal, medical, and behavioral – may increase the likelihood that a woman has preterm labor and delivers early.2 Compared to infants born at term, preterm infants are more likely to suffer lifelong neurologic, cognitive and behavioral problems.3,4 Preterm births and low birth weight are often, but not always, associated. Preterm births cost the U.S. health care system more than $26 billion each year.5

• Preterm births accounted for 8.0% of the 38,121 births to Orange County residents in 2016. While this is up slightly from 2015 (7.6%), it is down 18.4% from 2007 when preterm births were at 9.8%. By comparison, the rate for the United States was higher at 9.8% (5.8% decrease since 2007) in 2016.

• Disparities persist with preterm births among Black infants at 12.8%, followed by Hispanic (8.8%), White (7.9%), and Asian (7.3%) infants. The percentages decreased for all races and ethnicities, compared to 2007.

• Out of all preterm births, the percentage of preterm births was lowest among women less than 15 years old (0.03%) and highest among women 30 to 34 years old (32.2%).

• Women 40 years and older have the highest percentage of late preterm births (8.9%) compared to teens under 15 years of age who have no late preterm births (0.0%).

Note: Percent calculated from number of births with known obstetric estimate gestational age less than 37 weeks for 2014. Rates prior to 2014 were calculated from last menstrual cycle dates.

Agency; March of Dimes Report Card.

Orange County, 2016

Note: Percent calculated from number of births with known obstetric estimate gestational age less than 37 weeks for 2014. Rates prior to 2014 were calculated from last menstrual cycle dates.