The birth rate among unmarried women has increased since 1980; recent increases, however, are attributable primarily to increased births to cohabitating mothers rather than to single, unpartnered mothers.⁷ 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.⁸ However, it is important to continue to track outcomes of unmarried births as differences in racial and ethnic, economic, and other key demographic factors between births to unmarried compared with married women persist. 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.^7,9

Indicator FAM2.A: Birth rates for unmarried women by age of mother, 2011–2021

• In 2021, the birth rate for unmarried women ages 15–44 was 38 births for every 1,000 unmarried women. The rate was highest for unmarried women ages 25–29 (63 per 1,000), followed by women ages 30–34 (59 per 1,000), 20–24 (47 per 1,000), 35–39 (38 per 1,000), 18–19 (24 per 1,000), 40–44 (11 per 1,000), and 15–17 (6 per 1,000).
• From 2011 to 2021, birth rates for unmarried women under age 30 decreased, whereas birth rates for unmarried women age 30 and over increased.

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.¹⁰

Indicator FAM2.B: Percentage of all births to unmarried women by age of mother, 2011 and 2021

• The percentage of births to unmarried women of all ages decreased from 41% in 2011 to 40% in 2018 and then remained stable through 2021 at 41%.
• The percentage of births to unmarried women among adolescents ages 15–17 increased from 95% in 2011 to 98% in 2021; this percentage increased from 86% in 2011 to 90% in 2021 among women ages 18–19.
• Among women in their 20s, the percentage of births to unmarried women increased during the period. This percentage increased from 64% in 2011 to 68% in 2021 among women ages 20–24. For unmarried women ages 25–29, the percentage of births increased from 34% in 2011 to 41% in 2021.
• Among women age 30 and over, the percentage of births to unmarried women increased during the period. This percentage increased from 22% in 2011 to 26% in 2021 among women ages 30–34. For unmarried women ages 35–39, the percentage of births increased from 20% in 2011 to 24% in 2021. For unmarried women age 40 and over, the percentage of births increased from 22% in 2011 to 28% in 2021.

 FAM2A HTML Table FAM2B HTML Table