A verdict on the twenties

Six percent. Four percent. Those are the one-year drops in the birth rate for American women aged 20 to 24 and 25 to 29 in final 2025 data from the CDC, both to record lows. Then the sign flips: up 3% for women 30 to 34, 2% for 35 to 39, 1% for 40 to 44. Net it out and the general fertility rate fell 1%, to 53.2 births per 1,000 women aged 15 to 44, the lowest ever recorded and the number NPR led with on Saturday.

NPR's gloss is that the drop would have been greater if women over 30 weren't having more children. That reads as a cushion. It's closer to the mechanism. The record low isn't a turn away from children. It's a shift in when American women start, and the start age, more than the wish, sets how many children fit.

Demographers have a name for half of this. When births move later, a one-year rate falls even if no family ends up smaller, because the child a 24-year-old doesn't have this year isn't counted until she has it at 32. It's called a tempo effect, and it's why a period measure like the general fertility rate overstates a decline while the shift is under way. Some of 2025's record low is births that weren't cancelled, only rescheduled. The 30-to-34 rate, now 96.3 per 1,000 and the highest of any age group, is where they're arriving.

The other half is arithmetic about the calendar. Sum the CDC's age-specific rates and the 2025 total fertility rate comes to about 1.58 children per woman, down from 1.60. More than half of it, 52%, now comes from women 30 and older, up from 51% a year earlier. That's the part that should worry anyone reading the rising 30s as reassurance, because the curve past 35 drops fast: 55.2 births per 1,000 at 35 to 39, 12.8 at 40 to 44. A family that starts at 25 has fifteen years to grow. One that starts at 37 has a handful.

A family that starts at 25 has fifteen years to grow. One that starts at 37 has a handful.

NPR's own subjects show what that does to a family. Sarah Harris had her daughter at 37, was laid off four months later, and says the cost of raising a child convinced her one is enough.

Tanise Branche, medical director of labor and delivery at Temple Health, started at 37 and will be 43 at her fourth delivery. She's the exception, and she is using most of the window to be one.

The strongest objection is that this isn't about timing at all. The Atlanta Fed study NPR cites finds Gen Z women are dramatically less likely to want children than earlier generations, and if the wish is fading, the decline in the twenties is refusal, not delay. That's real, and a single year of period data can't separate the two; the number that can, completed fertility, arrives when today's 25-year-olds turn 45. But the paper's own title warns against stopping there: it's not only about preferences. And the same CDC report that set the record shows women 30 to 44 having children at higher rates than women the same age a year earlier. Delay is in the data. Whether it ends in a smaller family depends on how late it runs.

That changes what a pro-family policy would have to move. A payment at delivery arrives after the decision that's shifting. The decision happens years earlier, when a 26-year-old weighs whether her job and her rent can carry a child. That's the margin the 2025 numbers say is moving.

A birth rate that falls only below 30 isn't a verdict on children. It's a verdict on the twenties, and the twenties are the years a family has the most room to grow.