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Child Health USA 2013 An illustrated collection of current and historical data, published annually.

Preterm Birth

Narrative

Babies born preterm, before 37 completed weeks of gestation, are at increased risk of immediate life-threatening health problems, as well as long-term complications and developmental delays. Among preterm infants, complications that can occur during the newborn period include respiratory distress, jaundice, anemia, and infection, while long-term complications can include learning and behavioral problems, cerebral palsy, lung problems, and vision and hearing loss. As a result of these risks, preterm birth is a leading cause of infant death and childhood disability. Although the risk of complications is greatest among those babies who are born the earliest, even those babies born “late preterm” (34 to 36 weeks’ gestation) are more likely than full-term babies to experience morbidity and mortality.1

According to preliminary data for 2012, 11.54 percent of infants were born preterm. Overall, 8.13 percent of babies were born at 34 to 36 weeks’ gestation, 1.49 percent were born at 32-33 weeks’ gestation, and 1.93 percent were “very preterm” (less than 32 weeks’ gestation). Between 1990 and 2006, the preterm birth rate increased more than 20 percent from 10.62 to 12.80 percent, but has declined by nearly 10 percent since 2006. Recent declines are greatest among the largest category of late preterm infants born at 34 to 36 weeks’ gestation, which may be linked to practice-based efforts to reduce “elective” deliveries prior to 39 weeks that are not medically necessary.2

The preterm birth rate varies by race and ethnicity. In 2012, according to preliminary data, 16.53 percent of babies born to non-Hispanic Black women were born preterm, compared to 10.29 percent of babies born to non-Hispanic White women, and 10.15 percent of babies born to Asian/Pacific Islander women. Among babies born to Hispanic women, 11.58 percent were born preterm, while the same was true for 13.25 percent of babies born to American Indian/Alaska Native women. The causes of preterm birth are not well understood, but are linked to infection and vascular disease, as well as medical conditions, such as diabetes and hypertension, which may necessitate labor induction or cesarean delivery.3

1 Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Division of Reproductive Health. Prematurity. November 2009. Accessed: 04/23/13.

2 March of Dimes . Less than 39 weeks toolkit. Accessed: 04/23/13.

3 Goldenberg RL, Culhane JF, Iams JD, Romero R. Epidemiology and causes of preterm birth. Lancet. 2008 Jan 5;371(9606):75-84

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Graphs

This image is described in the Data section.

infant preterm by gestation weeks graph

This image is described in the Data section.

preterm infants by maternal race graph

Data

Preterm Birth, by Completed Weeks of Gestation, 1990-2012
Year Percent of Live Births after Less Than 32 Weeks Gestation Percent of Live Births after 32-33 Weeks Gestation Percent of Live Births after 34-36 Weeks Gestation Total
Source: Hamilton BE, Martin JA, Ventura SJ. Births: Preliminary data for 2012. National vital statistics reports; vol 62 no 3. Hyattsville, MD: National Center for Health Statistics. 2013. Source: Martin JA, Hamilton BE, Ventura SJ, et al. Births: Final data for 2011. National vital statistics reports; Vol 61 no 1. Hyattsville, MD: National Center for Health Statistics. 2013.
1990 1.92 1.40 7.30 10.62
1995 1.89 1.42 7.68 10.99
2000 1.93 1.49 8.22 11.64
2006 2.04 1.62 9.15 12.81
2012 (Data are preliminary) 1.93 1.49 8.13 11.54

Preterm Birth Among Infants, by Maternal Race/Ethnicity, 2012 (Data are preliminary)

Percent of Live Births:

  • Non-Hispanic White 10.29
  • Non-Hispanic Black 16.53
  • Hispanic 11.58
  • American Indian/Alaska Native (Includes Hispanics) 13.25
  • Asian/Pacific Islander (Includes Hispanics. Separate data for Asians, Native Hawaiians, and Other Pacific Islanders is not available.) 10.15

Source: Hamilton BE, Martin JA, Ventura SJ. Births: Preliminary data for 2012. National vital statistics reports; vol 62 no 3. Hyattsville, MD: National Center for Health Statistics. 2013.