Low birthweight (less than 5.5 pounds) is strongly associated with poor developmental outcomes, beginning in infancy but extending into adult life. Low weight is often associated with pre-term delivery, but can occur also with full-term births. Research points to a number of factors that can contribute to the likelihood of low weight at birth, including smoking during pregnancy; low weight gain during pregnancy, or low pre-pregnancy weight; and the pregnant parent’s stress during pregnancy. The National Center for Health Statistics defines low birth weight as a weight of less than 2,500 grams, or 5 pounds and 8 ounces. Data for the State of Babies Yearbook: 2022 were calculated using data from CDC Wonder. The denominator is the total number of all births whose weight is known, and the numerator is the number of those babies with low birthweight.This indicator can be disaggregated by race/ethnicity and urbanicity. Race/ethnicity: CDC Wonder contains very detailed information on the pregnant parent’s race/ethnicity. After examining sample sizes, we are presenting the following subgroups: non-Hispanic American Indian or Alaska Native, non-Hispanic Asian, non-Hispanic Black, non-Hispanic more than one race, non-Hispanic native Hawaiian or other Pacific islander, non-Hispanic White, and Hispanic of all races. The Division of Vital Statistics of the National Center for Health Statistics includes births with origin of the pregnant parent not stated with non-Hispanic births, according to the race of the pregnant parent in their reported statistics. We have excluded births with unknown Hispanic origins. Urbanicity: CDC Wonder classifies the pregnant parent as living in a metro (urban) or non-metro (rural) area according to 2013 designations. The metro group includes counties in these categories: large central metro, large fringe metro, medium metro, and small metro. The non-metro group includes counties in these categories: micropolitan (non-metro) and noncore (non-metro). For the subgroups, the total/national average is out of states whose data is presented for that subgroup, rather than all states.
Reichman, N. (2005). Low birth weight and school readiness. In School readiness: Closing racial and ethnic gaps. The Future of Children, 15(1), 91-116. https://doi.org/10.1353/foc.2005.0008 Ricketts, S. A., Murray, E. K., & Schwalberg, R. (2005). Reducing low birthweight by resolving risks: Results from Colorado’s Prenatal Plus Program. American Journal Public Health, 57(11),1952-1957. https://doi.org/10.2105/AJPH.2004.047068
United States Department of Health and Human Services (US DHHS), Centers for Disease Control and Prevention (CDC), National Center for Health Statistics (NCHS), Division of Vital Statistics. (2020). Natality public-use data 2019, on CDC WONDER Online Database, October 2020. http://wonder.cdc.gov/natality-expanded-current.html