- The average age of first-time mothers increased by 3.6 years from 21.4 in 1970 to 25.0 in 2006. These increases were more dramatic during the first two decades (1970 and 1980).

- The average age of first-time mothers increased for all states and the District of Columbia between 1970 and 2006.

- Between 1990 and 2006, the average age at first-birth increased for all racial and ethnic groups, from 0.6 years for American Indian and Alaska Native women to 1.7 years for Asian and Pacific Islander women.

- The average age at first birth has steadily increased among developed nations, and in 2006, the average age of first birth ranged from 25.0 in the United States to 29.4 in Switzerland (other selected countries are featured in Figure 5 in the report).

- Generally, age of first-time mothers was greater on the East and West coasts and in northern state, and increased less in the mid-west and central southern states.

http://www.cdc.gov/nchs/pressroom/data/DB21.pdf