Low Birth Weight in Birth Outcomes: Measures and Data
Why is low birth weight a public health issue?Low birth weight is a risk factor for infant death, and is associated with a higher risk of health problems throughout life, including chronic diseases like asthma and high blood pressure. States and local governments all over the world monitor low birth weight rates as a marker of overall population health and as a marker of disparities between sub-populations.
The cost of caring for low birth weight babies and treating the long term health consequences of low birth weight likely outweigh the costs of prevention, making reduction of low birth weight a sensible and common public health objective. In Washington, the overall singleton (one baby) low birth weight rate has increased since 1990, although the LBW rate has declined for some sub-populations. The Maternal and Child Health Data Report and the Perinatal Indicators Report for Washington Residents provide more detailed statistics on these trends.
How is low birth weight defined and tracked?Low birth weight (LBW) is defined as any live birth under 2500 grams (5 lbs 8 oz). The rate of low birth weight in a population depends on whether the indicator includes or excludes multiple births, and whether the count includes only full-term births or also includes pre-term births. Total LBW usually refers to all live singleton and multiple births under 2500 grams, per 100 live births, including both pre-term babies and term babies that had low weight. By contrast, Environmental Public Health Tracking uses “term LBW” which counts only those babies born at 37 weeks or later, as described in the Query System data notes. LBW indicators are calculated using birth certificate data.
In Washington, the state Department of Health (DOH) Center for Health Statistics collects birth data through the Vital Registration System. The State Registrar reports birth data to CDC National Center for Health Statistics, which maintains files on all births in the United States and its territories. Data are standardized among all jurisdictions and are generally available one year later than state data.
What is being done to prevent low birth weights? In Washington, the State Department of Health and Department of Social and Health Services (DSHS) work with a variety of partners in the state to carry out programs that work to prevent low birth weight and promote healthy births, including:
These services address issues that promote healthy birth outcomes such as birth spacing, prenatal medical care access, smoking cessation, alcohol and drug use prevention, healthy weight gain, and addressing family violence.
- State Title X Family Planning Program: family planning and women’s health services
- Special Supplemental Nutrition Program for Women, Infants and Children (WIC): breastfeeding support, nutritious foods, education and referrals to preventive services
- First Steps Program: prenatal medical care, Maternity Support Services, Infant Case Management
- Take Charge Program: family planning services for low income men and women
Other Department of Health activities include data surveillance, perinatal quality improvement projects, and development and dissemination of preconception healthy living messages.
More Information on Specific Birth Outcomes