The birth rate among married women has increased overall since 1980. Recent increases are primarily due to increased births to mothers living with a partner rather than to single, unpartnered mothers.¹ Moreover, the demography of unmarried births has changed over the past 40 years. Unmarried births to younger mothers, particularly teens, have declined, whereas births to older mothers, including first births, have increased.² However, it is important to continue to track outcomes of unmarried births as differences persist in racial and ethnic, economic, and other key demographic factors between births to unmarried women and those to married women. Historically, children of unmarried mothers are at a higher risk of adverse birth outcomes, such as low birthweight, preterm birth, and infant mortality, compared with children of married mothers.^{1, 3}

Indicator FAM1.A Birth rates for unmarried women by age of mother, 2013–2023

• In 2023, the birth rate for unmarried females ages 15–44 was 36 births for every 1,000 unmarried females.
• The birth rate was highest for unmarried women ages 30–34 (58 per 1,000) and 25–29 (57 per 1,000), followed by women ages 20–24 (45 per 1,000), 35–39 (39 per 1,000), 18–19 (23 per 1,000), 40–44 (12 per 1,000), and 15–17 (5 per 1,000).
• From 2013 to 2023, birth rates decreased for unmarried women under age 30, whereas birth rates varied for unmarried women age 30 and over. Birth rates did not significantly change for unmarried women ages 30–34 and increased for unmarried women ages 35–39. For unmarried women ages 40–44, birth rates increased from 2013 to 2019 and then remained stable year to year through 2023.

The proportion of births to unmarried women is useful for understanding the extent to which children born in a given year may be affected by any disadvantage—social, financial, or health—associated with being born outside of marriage. The change in the percentage of births to unmarried women reflects both changes in the birth rate for unmarried women relative to the birth rate for married women and changes in the percentage of women of childbearing age who are unmarried.⁴

Indicator FAM1.B Percentage of all births to unmarried women by age of mother, 2013 and 2023

• The percentage of births to unmarried females of all ages did not significantly change from 2013 to 2023. In 2023, 40% of births were to unmarried females.
• Among females under age 20, the percentage of births to unmarried females increased from 2013 to 2023. For females ages 15–17, the percentage of births to unmarried females increased from 95% in 2013 to 98% in 2021 and then remained stable through 2023. For women ages 18–19, the percentage of births to unmarried women increased from 86% in 2013 to 90% in 2023.
• Among women in their 20s, the percentage of births to unmarried women generally increased during this time period. For women ages 20–24, the percentage of births to unmarried women increased from 65% in 2013 to 68% in 2023. For women ages 25–29, the percentage of births to unmarried women increased from 36% in 2013 to 41% in 2020 and then remained stable through 2023.
• Among women in their 30s, the percentage of births to unmarried women increased during this time period. For women ages 30–34, the percentage of births to unmarried women increased from 22% in 2013 to 27% in 2023. For women ages 35–39, the percentage of births to unmarried women increased from 21% in 2013 to 25% in 2023.
• Among women age 40 and over, the percentage of births to unmarried women increased from 24% in 2013 to 28% in 2021 and then remained stable through 2023 (27% in 2023).

 FAM1A HTML Table | FAM1B HTML Table