This metric shows births to mothers who either received no prenatal care or began care after the first trimester (after 12 weeks of gestation). It is presented as a percentage of all live births, reported by single calendar years.

Total births at the ZIP code level were calculated by the Tulsa Health Department (THD) using raw data files from the Oklahoma State Department of Health (OSDH), Center for Health Statistics, Health Care Information.

For county-level data, an alternate source is the Oklahoma State Department of Health (OSDH), Center for Health Statistics, Health Care Information, accessed via Oklahoma Statistics on Health Available for Everyone (OK2SHARE) at http://www.health.ok.gov/ok2share.