The birth rate among unmarried women has increased since 1980; however, more recently, this increase is largely due to the rise in births to cohabitating mothers rather than an increase in births 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, 10}

Indicator FAM2.A: Birth rates for unmarried women by age of mother, 2009–2019

• In 2019, the birth rate for unmarried women ages 15–44 was 40 births for every 1,000 unmarried women. The rate was highest for unmarried women ages 25–29 (62 per 1,000), followed by women ages 30–34 (61 per 1,000), 20–24 (52 per 1,000), 35–39 (36 per 1,000), 18–19 (28 per 1,000), and 40–44 (11 per 1,000).
• The birth rate for unmarried women was lowest among adolescents ages 15–17 (7 per 1,000).to 40 per 1,000. During the period, birth rates for unmarried women ages 15–17, 18–19, 20–24, and 25– 29 declined, whereas birth rates for unmarried women ages 30–34, 35–39, and 40–44 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, 11}

Indicator FAM2.B: Percentage of all births to unmarried women by age of mother, 2009 and 2019

• The percentage of all births to unmarried women declined slightly from 41% in 2009 to 40% in 2019.
• Between 2009 and 2019, the percentage of births to unmarried women among adolescents ages 15–17 increased from 94% in 2009 to 97% in 2019; among women ages 18–19, the percentage increased from 84% in 2009 to 88% in 2019.
• Among women in their 20s, the percentage of births to unmarried women increased during the period. For women ages 20–24, the percentage of births increased from 62% in 2009 to 67% in 2019. For women ages 25–29, the percentage of births increased from 34% in 2009 to 40% in 2019.
• Among women age 30 and over, the percentage of births to unmarried women increased during the period. For women ages 30–34, the percentage of births increased from 21% in 2009 to 25% in 2019. For women ages 35–39, the percentage of births increased from 19% in 2009 to 23% in 2019. For women age 40 and over, the percentage of births increased from 21% in 2009 to 26% in 2019.

 FAM2A HTML Table FAM2B HTML Table