Births: final data for 1999.

OBJECTIVES This report presents 1999 data on U.S. births according to a wide variety of characteristics. Data are presented for maternal demographic characteristics including age, live-birth order, race, Hispanic origin, marital status, and educational attainment; maternal characteristics (medical risk factors, weight gain, tobacco and alcohol use); medical care utilization by pregnant women (prenatal care, obstetric procedures, complications of labor and/or delivery, attendant at birth, and method of delivery); and infant characteristics (period of gestation, birthweight, Apgar score, abnormal conditions, congenital anomalies, and multiple births). Also presented are birth and fertility rates by age, live-birth order, race, Hispanic origin, and marital status. Selected data by mother's State of residence are shown, as well as data on month and day of birth, sex ratio, and age of father. Trends in fertility patterns and maternal and infant characteristics are described and interpreted. METHODS Descriptive tabulations of data reported on the birth certificates of the 3.96 million births that occurred in 1999 are presented. RESULTS Overall birth and fertility rates changed less than 1 percent in 1999. Teenage birth rates fell 2 to 6 percent. The rate for women aged 20-24 years declined slightly, while rates for women in their late twenties and their thirties rose 2 to 3 percent each. The number of births to unmarried women, the birth rate, and the percent of births that were to unmarried women each rose 1 percent or less. Smoking by pregnant women overall dropped again, but rose among women aged 18-24 years. Improvements in prenatal care utilization continued. The cesarean delivery rate increased for the third year after declining for 7 consecutive years. The proportion of multiple births continued to rise; however, higher order multiple births (e.g., triplets, quadruplets) declined for the first time in over a decade, following increases of 13 percent per year during 1990-98. The percent low birthweight remained at 7.6 percent, while preterm births rose to 11.8 percent. These trends are in large part the result of increases in multiple births.