Births: preliminary data for 2004.

OBJECTIVES This report presents preliminary data for 2004 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, tobacco use, prenatal care, cesarean delivery, preterm births, and low birthweight (LBW) are also presented. METHODS Data in this report are based on 99.1 percent of births for 2004. The records are weighted to independent control counts of all births received in State vital statistics offices in 2004. Comparisons are made with 2003 data. RESULTS The crude birth rate declined 1 percent to 14.0 births per 1,000 population. The fertility rate, however, rose slightly to 66.3 births per 1,000 women aged 15-44 years. Birth rates for teenagers 15-19 years declined modestly. The rate in 2004 was 41.2 births per 1,000 females aged 15-19 years, 1 percent lower than in 2003. Rates declined 1 percent each for teenagers 15-17 and 18-19 years. The rate for 10-14 year-olds increased slightly. The birth rate for women aged 20-24 years declined 1 percent to 101.8, a record low for the Nation. The rate for women aged 25-29 years remained essentially unchanged at 115.5 per 1,000. The birth rate for women aged 30-34 years rose less than 1 percent to 95.5 per 1,000, whereas the rates for women aged 35-39 and 40-44 years increased 3 to 4 percent each. The rate for women aged 45-49 years rose to 0.6 per 1,000. Childbearing by unmarried women rose to a record high of almost 1.5 million births in 2004, a 4-percent increase from 2003. The proportion of all births to unmarried women increased to 35.7 percent. Smoking during pregnancy declined slightly in 2004, to 10.2 percent of mothers in the 40-State reporting area. There was no improvement in timely receipt of prenatal care. In 2004, 83.9 percent of mothers in the 41-State reporting area began care in the first trimester. A record high cesarean delivery rate was reported in 2004, at 29.1 percent of all births, a 6-percent increase from 2003. The primary cesarean rate rose 8 percent, whereas the rate of vaginal birth after cesarean delivery declined 13 percent. Preterm and LBW rates each increased in 2004. More than 500,000 infants were born preterm, a rate of 12.5 percent. The LBW rate increased to 8.1 percent.