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

Low Birth Weight

Narrative

Infants born at low birth weight (less than 2,500 grams or 5.5 pounds) and especially very low birth weight (less than 1,500 grams or 3.25 pounds) are more likely than infants of normal birth weight to die in the first year of life and to experience long-range physical and developmental health problems. The majority of very low birth weight infants are born prematurely, whereas those born at moderately low birth weight include a mix of prematurity as well as fetal growth restriction, which may be related to factors such as maternal hypertension, tobacco smoke exposure, or inadequate weight gain during pregnancy.1

According to preliminary data for 2012, 7.99 percent of infants were born at low birth weight, including 1.42 percent who were born at very low birth weight. After steady increases, rates of low and very low birth weight peaked in 2006 at 8.26 and 1.49 percent, respectively, and have declined only slightly since then. Reasons for the increase in low birth weight may mirror those behind increases in prematurity, including increases in obstetric interventions, maternal age, and fertility treatments.2 A rise in multiple births, which increase with maternal age and fertility treatments and are at high risk of low birth weight, has strongly influenced the rise in low birth weight; however, rates of low birth weight have also increased for singleton births.3

Infants born to non-Hispanic Black women have the highest rates of low and very low birth weight (13.18 and 2.94 percent, respectively), levels that are about two or more times greater than for infants born to women of other race and ethnic groups. For example, low and very low birth weight rates among non-Hispanic Whites were 6.97 and 1.13 percent, respectively. Given their heightened risk of death, the large disparity in very low birth weight is a major contributor to the mortality gap between non-Hispanic Black and White infants.4 In 2009, 23.1 percent of very low birth weight infants died in the first year of life, compared to 5.3 percent of all low birth weight infants and 0.2 percent of normal birth weight infants.5

1 March of Dimes . Low Birth Weight. Accessed: 04/08/13.

2 Martin JA, Hamilton BE, Sutton PD, Ventura SJ, et al. Births: Final data for 2006. National vital statistics reports; vol 57 no 7. Hyattsville, MD: National Center for Health Statistics. 2009.

3 Martin JA, Hamilton BE, Sutton PD, Ventura SJ, et al. Births: Final data for 2006. National vital statistics reports; vol 57 no 7. Hyattsville, MD: National Center for Health Statistics. 2009.

4 Wise PH. The anatomy of a disparity in infant mortality. Annu Rev Public Health. 2003;24:341-62.

5 Mathews TJ, MacDorman, MF. Infant Mortality Statistics from the 2009 Period Linked Birth/Infant Death Data Set. National Vital Statistics Reports; vol 61 no 8. Hyattsville, MD: National Center for Health Statistics. 2013.

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Graphs

This image is described in the Data section.

infant low birthweight graph

This image is described in the Data section.

infant low birthweight by maternal race graph

Data

Low and Very Low Birth Weight, 1990–2012 (Data are preliminary)
Year Percent of Live Births with Low Birth Weight of Fewer Than 2,500 grams

Percent of Live Births with Very Low Birth Weight of Fewer

Than 1,500 grams

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 6.97 1.27
1995 7.32 1.35
2000 7.57 1.43
2005 8.19 1.49
2012 7.99 1.42
Low and Very Low Birth Weight, by Maternal Race/Ethnicity, 2012 (Data are preliminary)
Race/Ethnicity Percent of Live Births with Low Birth Weight of Fewer Than 2,500 grams Percent of Live Births with Very Low Birth Weight of Fewer Than 1,500 grams
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.
Non-Hispanic White 6.97 1.13
Non-Hispanic Black 13.18 2.94
Hispanic 6.96 1.22
American Indian/Alaska Native (Includes Hispanics) 7.61 1.33
Asian/Pacific Islander (Includes Hispanics. Separate data for Asians, Native Hawaiians, and Other Pacific Islanders is not available.) 8.21 1.13