Washington: Low birth weight babies Note: A "low" birthweight is below 2,500 grams, or roughly 5 lbs 8 oz. Percent low birth weight babies is calculated by dividing the number of low birth weight babies by the number of live births. It is presented on a "per 100" basis. NA = Not Reported or Not Available. Source: 1997-2018: Idaho Department of Health and Welfare (http://www.healthandwelfare.idaho.gov/Health/HealthStatistics/tabid/102/Default.aspx); 1997-2018: National Center for Health Statistics, Birth Data (http://www.cdc.gov/nchs/births.htm); DATE LAST UPDATED: November 30, 2020.