The share of American mothers who reach the end of their childbearing years with only one child has more than doubled over the past four decades, and federal data released in the past year shows the forces behind that shift are still pushing in the same direction. A Pew Research Center analysis of government fertility data found that just 11% of mothers ages 40 to 44 had only one child in 1976; by 2014, that share had climbed to 22%, a record high in the tracked data and roughly double where it started.
- Record share: 22% of mothers finishing their childbearing years now have only one child, up from 11% in 1976, per Pew’s analysis of federal data.
- Fertility still falling: the CDC’s National Center for Health Statistics confirmed the 2024 U.S. fertility rate fell another 1% from 2023, even as total births ticked up slightly to 3,628,934.
- Births shifting older: the same CDC data shows birth rates fell for women under 35 in 2024 but rose for women ages 40 to 44 — a pattern consistent with more parents having children later and stopping sooner.
- Families with kids shrinking overall: the U.S. Census Bureau reported that just 39% of families now include their own children under 18, down from 54% in 1975.
The trend isn’t limited to any one group of women, though the newest breakdown adds nuance. A 2025 family profile from Bowling Green State University’s National Center for Family & Marriage Research, built on Current Population Survey data through 2024, found the share of never-married women ages 40-44 who are mothers at all jumped from 39% in 2000 to 52% in 2024. Within that same group, though, the share who stopped at exactly one child actually slipped slightly, from 29% to 24% — a reminder that the one-child pattern isn’t uniform across every household type even as it climbs in the aggregate.
Delayed marriage plays a role too. Census data shows the median age at first marriage has climbed to 30.8 for men and 28.4 for women in 2025, up from 23.5 and 21.1 in 1975 — a five-to-seven-year shift that compresses the biological window couples have to have more than one child even when they’d like to. Cost is a factor researchers and family demographers point to consistently as well, alongside greater workforce participation among mothers and wider access to family planning than existed in the 1970s.
None of the newest releases from Pew, the CDC, or the Census Bureau show the one-child trend reversing. If anything, the 2024 and 2025 data points reinforce the same direction Pew first flagged: fewer children per family, later first births, and a growing share of American parents who have one child and stop there — a shift with obvious implications for classroom sizes, extended-family gatherings, and the sibling relationships an entire generation of only children is growing up without.
