The number of women who are choosing to wait until they are older to start their families has been on the rise over the past three and a half decades. The average age of first-time mothers has increased by 3.6 years over last 36 years, from the age of 21.4 years in 1970 to the age of 25 in 2006.
Researchers T.J. Mathews and Brady E. Hamilton of the Center for Disease Control and Prevention’s (CDC) National Center for Health Statistics, Division of Vital Statistics, Reproductive Statistics Branch, analyzed data from the birth data set to derive the new information. The birth data set is primarily used for analyzing U.S. birth trends and patterns, and is a part of the National Vital Statistics System that contains information on reported live births in the U.S.
The researchers were interested in pinning down the average age of first-time mothers since the age of a woman’s first birth has a bearing on the total number of births she may have within her lifetime. In turn, this has an impact on family size and future increase in the overall population. In addition, a mother’s age, whether younger or older has an effect on outcomes of births including birth weight, multiple births, and birth defects.
Increases were seen in the average age of first-time mothers for all states and the District of Columbia between the years of 1970 and 2006. The rise in average childbearing age for the lower end of the range included 2.0 years in New Mexico, 2.3 years in Mississippi, 2.4 years in Oklahoma, and 2.5 years in Utah. The District of Columbia had the highest age average at 5.5 years, followed by Massachusetts at 5.2 years, New Hampshire at 5.1 years and both Vermont and New Jersey having an average increase in childbearing age of 4.8 years.
The report showed that the most dramatic increases in the average age at first birth were seen during the 1970s and 1980s. In addition, the largest role played in the overall increased average age of new mothers was observed to be in the age range of 35 years and over.
Other evidence supporting the rising average age of first-time mothers can be seen in another recent report released by the CDC revealing that non-marital births to women from 25 to 29 has risen nearly one-third since 2007. On the other hand, a recent CDC Morbidity and Mortality Weekly Report showed that the numbers for teen births in both 2006 and 2007 were on the rise due to lack of better sex education including emphasis on pregnancy prevention as well as sexually transmitted diseases.
The report also reflected that the average age at first birth has increased for all racial and ethnic groups over the 36-year period, with increases ranging from 0.6 years for American Indian or Alaska Native women to 1.7 years for Asian or Pacific Islander women.
In addition to increase in the U.S. average age of first birth, other developed nations have experienced a rise in their averages as well. The average age in Switzerland in 2006 was 29.4 years (compared to 25.0 years in the United States). Since 1970, Sweden’s age of first birth has risen by 2.9 years, while Denmark’s average age for new mothers has increased by 4.6 years. Asian or Pacific Islander women had the oldest average age at first birth in 2006 at 28.5 years, while American Indian or Alaska Native women had the youngest average at 21.9 years.