First-time mothers are older than ever, new federal data has revealed. Since 2000, the average mother’s age at the birth of her first child has increased in every state in the nation, rising 1.9 years or more in D.C., California, Oregon, and Utah, while increasing by less than a year in Connecticut, Michigan, New Hampshire, and West Virginia. Overall, the average age of mothers has increased from 2000 to 2014 for all birth orders, with age at first birth having the largest increase, up from 24.9 years old in 2000 to 26.3 years in 2014, according to newly released data compiled by the Centers for Disease Control and Prevention. Connecticut is among a dozen states with the smallest increases in the average age of first-time mothers.
The federal agency points out that “a mother's age at birth, and particularly the average age when a mother has her first child, is of interest to researchers and the public. Mean age can affect the total number of births a mother has over a lifetime, which in turn impacts the composition and growth of the U.S. population. Age of mother is associated with a range of birth outcomes, such as multiple births and birth defects, the agency noted.
The largest factor in the rise a mother’s average age when her first child is born is the decline in the proportion of first births to mothers under age 20, down 42 percent from 2000 to 2014, or from approximately 1 in 4 births to 1 in 7.
Increases in the average age for all birth orders were most pronounced from 2009 to 2014, according to the data. While the average age at the birth of a mother’s first child was fairly stable for the first half of this time period, greater increases were observed from 2009 (25.2 years) to 2014 (26.3 years).
Increases from 2000 to 2014 in average age for higher birth orders were less than those for first births, rising 1.4 years for first births, 1.0 years for second births, 0.8 years for third- and fourth-order births, and 0.5 years for fifth- and higher-order births. As a result of the different rate of increases by birth order, the gap in the average age between sequential birth orders is less than previously. For example, the difference in a mother’s average age at first birth compared with the mean age at second birth was 2.8 years in 2000 and fell to 2.4 years in 2014.
States with larger increases (1.7 years or more) in the average age at first birth tended to be in the western United States (California, Oregon, Washington, Utah, and Colorado), the data indicated. Greater increases were also seen in Illinois, Arkansas, and D.C.
The report emphasized that over the past several decades, the United States continued to have a larger number of first births to older women along with fewer births to mothers under age 20. “This trend and the more recent uptick in delayed initial childbearing can affect the number of children a typical woman will have in her lifetime, family size, and for the overall population change in the United States,” the federal agency pointed out.
This report contains data from the birth data set, which is part of the National Vital Statistics System (NVSS). NVSS contains all live births reported in the United States. The birth data set is the primary data set for analyzing birth trends and patterns in the United States.