Amid growing evidence of slowing fertility rates in the United States, a new report contained a pair of surprising details from two divergent age groups: A growing number of women older than 40 are having children and a record low number of teenagers are giving birth.
The report, released earlier this month by the National Center for Health Statistics (NCHS), showed that the U.S. fertility rate — the average number of children born to a woman during her reproductive years — continued its decadeslong slide through 2023, with American women having an average of 1.62 children, compared to 1.66 in 2021 and 2022.
Overall, the rate has declined 14% since 1990, driven largely by younger women under the age of 30 who are having fewer children.
For the first time in 2023, there were more births among women 40 and older than there were to teenage girls, a trend which aligns with both long-sought public health goals of decreasing teen births, while reflecting medical advancements which have allowed older women to have healthy pregnancies.
“There’s a flip in the age distribution,” said Elizabeth Wildsmith, a family demographer and sociologist at Child Trends, a nonpartisan research group.
In 1990, adolescents accounted for almost 13% of all births; in 2023, they made up 4%. And most critically, the fertility rate for girls ages 10 to 14 dropped from 1.4 to almost zero, something Wildsmith called “a success story” from a public health perspective.
At the same time, demographers are still trying to discern why women are choosing to become pregnant and give birth later. The most recent data show that most births now occur to women ages 30 to 34, while a decade ago the cohort that was most likely to give birth was 25 to 29.
As the average maternal age has increased, far more women ages 35 and older are also having children, according to the NCHS, part of the Centers for Disease Control and Prevention which tallies all known births in the U.S. From 1990 to 2023, the fertility rate for women ages 35 to 39 increased 71%, and for women ages 40 to 44, the rate increased 127%.
Researchers say that there are a number of possible explanations for the gradual increase in the age of new mothers, including evolving social expectations and values; changes in technology and dating behavior; the economic burden of child rearing; and increasing college enrollment among women.
“All of those conditions shape when people want to start having children,” said Wildsmith, who also noted that when “women are able to control their fertility,” other opportunities — including professional, political and economic — become easier to access.
