Most first-time mothers in the United States are in their late 20s, with the average age at first birth reaching 27.5 years in 2023. That number has climbed steadily from 21.4 in 1970, reflecting one of the most dramatic demographic shifts in modern family life. The age people have kids varies widely by country, income, education, and geography, but nearly everywhere the trend points in the same direction: older.
The Current Average in the U.S.
CDC data shows the mean age of first-time mothers rose from 26.6 in 2016 to 27.5 in 2023, gaining nearly a full year in just seven years. For all births (not just first children), the average maternal age is 29.6. Second children arrive around age 30, and third or later children around 31.9.
The highest birth rates in 2024 belonged to women ages 30 to 34, at 93.7 births per 1,000 women in that age group. Women 25 to 29 were close behind at 89.5 per 1,000. This marks a notable reversal from past decades, when the 25-to-29 bracket consistently led. Birth rates for women in their early 20s continue to fall, dropping 3% from 2023 to 2024 alone. Meanwhile, the birth rate for women 40 to 44 actually rose 2% in that same year, to 12.7 per 1,000.
How This Has Changed Over Time
In 1970, the average American woman had her first child at 21.4. By 2017, that figure had jumped to 26.8, and it has continued climbing since. That’s more than six years of shift in roughly two generations. The change hasn’t been uniform across states. By 2010, the gap between the youngest and oldest state-level averages for first birth had widened to 5.6 years, with some states averaging around 24 and others closer to 30.
Why People Are Waiting Longer
The reasons are layered and reinforce each other. Effective contraception gave people the ability to choose timing. Rising educational attainment, especially among women, pushed parenthood later because balancing student life and motherhood is extremely difficult in practice. People who pursue higher degrees tend to delay children until they’re established in a career, partly because they want financial stability and partly because their earning potential rises steeply with age, making it rational to wait.
Housing costs play a real role too. The housing market acts as an unintentional gate on family formation: when people can’t secure stable housing, they’re less likely to start families. Economic uncertainty more broadly, including temporary contracts and unstable job markets, makes it hard for people to commit to the long-term financial obligations that come with raising a child. These pressures hit younger adults hardest, which helps explain why birth rates among women under 25 keep declining.
There’s also a strong connection between early parenthood and financial hardship. Research has consistently found that having a first child at a younger age is associated with higher rates of poverty by the late 20s, across all racial groups. The relationship works through several channels: more total children over time, lower personal earnings, and reduced household income.
How Other Countries Compare
The trend toward older parenthood is global across wealthy nations, but the range is wide. In Turkey, the average age at first birth is around 26.6, similar to where the U.S. was a few years ago. In South Korea, it’s 32.6, the highest among OECD countries. Every OECD nation with available data has seen the average age at first birth rise since 2000, with most recording an increase of at least two years. In Estonia, South Korea, and Lithuania, the jump has been over four years in that period.
Fertility and Age: What Biology Allows
While social and economic factors push the timing of parenthood later, biology sets limits. Fertility begins declining gradually in the early 30s and drops more noticeably after 35. By the early 40s, natural pregnancies become uncommon. Miscarriage rates also rise with maternal age, climbing significantly after 35 and more steeply after 40.
This creates a real tension for many people. The ages that make the most sense financially and professionally for starting a family often overlap with the years when conceiving becomes harder. For women in their late 30s and early 40s, each year of delay carries more biological weight than it did in their 20s.
Age Matters for Fathers Too
Paternal age gets less attention, but it carries its own risks. Researchers generally define “older fathers” as those 40 and above. A large meta-analysis found that compared to fathers aged 25 to 29, men 40 and older had a modestly increased risk of having children with heart abnormalities, urogenital issues, and chromosomal disorders. Very young fathers (under 20) also showed elevated risks for some of the same conditions. The 25-to-29 range consistently showed the lowest risk profile for offspring health.
The increases in risk are small in absolute terms, but they’re statistically consistent across multiple studies. Unlike maternal age, which affects the ability to conceive as well as pregnancy outcomes, paternal age primarily shows up in slightly higher rates of certain birth differences rather than in difficulty conceiving.
Assisted Reproduction and Later Parenthood
IVF and other fertility treatments have expanded the window for parenthood, but they don’t eliminate the age factor. Success rates for IVF decline with age in a pattern that roughly mirrors natural fertility. The CDC tracks outcomes from fertility clinics nationwide, and the data consistently shows that live birth rates per cycle are highest for women under 35 and fall progressively with each additional year. By the early 40s, multiple cycles are often needed, and success rates drop substantially. The technology helps, but it works best when started earlier rather than later.
The Practical Picture
If you’re wondering where you fall in all of this, the short answer is that most Americans now have their first child somewhere between 25 and 34, with the center of gravity sitting right around 28. Having kids in your early 20s is increasingly uncommon but still happens. Having kids after 35 is increasingly common and continues to rise. Having kids after 40 remains relatively rare but is the only age group where birth rates are actually growing.
The “right” time depends on a collision of personal, financial, and biological factors that look different for everyone. What the data makes clear is that the social norm has shifted dramatically. A first-time parent at 30 today is squarely in the mainstream, while the same would have been considered late a generation ago.