How have US fertility and birth rates changed over time?

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Women are giving birth to fewer children on average and increasingly opting to start their families later in life. These evolving patterns carry implications for the demographic makeup of the United States, including, potentially, an aging population and a diminishing workforce. To understand these transformations, governmental agencies rely on such metrics as fertility and birth rates.

State and federal agencies collect this fertility data in different ways and at different times, making for data that covers diverse but often overlapping periods. Looking at this data together creates a picture of changing trends.

How are fertility rates calculated?

The Centers for Disease Control and Prevention (CDC), defines the general fertility rate as the number of births per 1,000 women ages 15–44. This measure differs from age-specific birth rate, which the CDC defines as the number of live births per 1,000 women in a specified age group.

Measuring a nation’s fertility and birth rates creates a greater understanding of demographic shifts over time.

How has the fertility rate changed over time?

The nation’s fertility rate has generally declined since 1957 when there were 122.9 births per 1,000 women ages 15–44. Preliminary 2022 data shows the fertility rate was less than half this, at 56.1.

Line graph showing the US fertility rate over time. Besides a spike in the 1950's, the fertility rate has mostly decreased.

How have birth rates changed by age?

Women are having children later in life. From 2006 to 2019, birth rates for women ages 29 and younger decreased but rose for women 30 and older. Rates dropped the most — by 38% —for women ages 20–24, dropping from 92.3 to 57.2.

How do fertility rates vary by state?

In 2021, the fertility rate was highest in South Dakota (68.6 births) and lowest in Vermont (44.9 births).

Overall, the fertility rate remains lowest in the West Coast and Northeast and highest in the Midwest and South.

How do fertility rates vary by state over time?

North Dakota and Louisiana are the only states that increased their fertility rates between 2005 and 2021. North Dakota had the greatest increase, 2.93%, while Louisiana’s rose 1.13%.

The fertility rate particularly dropped in Southwestern states between 2005 and 2021. Utah and Arizona were neck and neck at a 31.47% decrease and 31.14% decrease, respectively.