A report by the Centers for Disease Control and Prevention in Atlanta also found the birth rates for younger and older teenagers and for all race/ethnic groups reached historic lows in 2010.
However, the total number of U.S. births declined 3 percent, from 4,130,665 in 2009 to 4,000,279 in 2010 -- similar to the 4 million births at the peak of the baby boom in 1957, CDC statistician Bradley Hamilton told UPI.
In 17 of the past 19 years, the teen birth rate fell to 34.3 births per 1,000 teenagers in 2010 -- a 9 percent decline from 2009 and the lowest rate in nearly seven decades of collecting data, the report said.
The report also found in 2010, the Caesarean section rate was 32.8 per 100 births down slightly from 32.9 per 100 births in 2009 -- the first decline in the rate of Caesarean deliveries since 1996.
The overall fertility rate also fell by 3 percent from 66.2 births per 1,000 females ages 15-44 in 2009 to 64.1 in 2010. This is the third straight decline for the overall U.S. fertility rate, officials said.
The total number of births to unmarried mothers declined for the second year in a row to 1,633,785, down from 1,693,658 in 2009, while the percentage of births to unmarried mothers also declined slightly in 2010 to 40.8 percent compared with 41 percent in 2009, the report said.