But the percentages of premature and low birth weight babies climbed, continuing the rise of recent years.
The birth rate was 13.9 per 1,000 persons in 2002, the Health and Human Services Department announced. That compares with 14.1 a year ago. The most recent high was 16.7 in 1990.
The latest figure is the lowest in government records that go back to the turn of the 20th century, according to Brady Hamilton, a demographer at the National Center for Health Statistics.
A major factor in the decline has been the reduction in births to teenagers in recent years, Health and Human Services Secretary Tommy Thompson said. He called that "a significant accomplishment."
Other factors also play a part, including the aging of the population, added Hamilton.
Hamilton noted that women in their prime childbearing years have been choosing to have fewer children and, as the population ages, there are fewer women in their 20s and 30s.
Overall, there were 4,019,280 births in the United States in 2002, down from 4,025,933 the year before.
Some 12 percent of last year's births were premature, compared with 11.9 percent in 2001. In addition, 7.8 percent were listed as low birth weight, which the center said was at the highest level in more than 30 years. Last year's rate was 7.7 percent.
Those increases came despite greater access to prenatal care. The center said 83.8 percent of women began receiving care in the first trimester of pregnancy last year, compared with 83.4 percent in 2001 and 75.8 percent in 1990.
The birth rate for unmarried women declined last year to 43.6 per 1,000 unmarried women, but this group still accounted for more than one-third of all births.
Other findings in the study of births in 2002 included:
By Randolph E. Schmid