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
NOTE: Rates for women ages 40–44 are computed by dividing the number of births to unmarried women age 40 and over by the population of unmarried women ages 40–44.
SOURCE: National Center for Health Statistics, National Vital Statistics System.
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
SOURCE: National Center for Health Statistics, National Vital Statistics System.
FAM2A HTML Table FAM2B HTML Table
7 Smock, P. J., & Schwartz, C. R. (2020). The demography of families: A review of patterns and change. Journal of Marriage and Family, 82(1), 9–34.
8 Martin, J. A., Hamilton, B. E., Osterman, M. J. K., & Driscoll, A. K. (2021). Births: Final data for 2019. National Vital Statistics Reports, 70(2). National Center for Health Statistics.
9 Livingston, G. (2015). For most highly educated women, motherhood doesn't start until the 30s. Fact Tank: News in the numbers. Pew Research Center.
10 Martin, J. A., Hamilton, B. E., Osterman, M. J. K., & Driscoll, A. K. (2019). Births: Final data for 2018. National Vital Statistics Reports, 68(13). National Center for Health Statistics.
11 The birth rate for unmarried women is the number of births per 1,000 unmarried women in a given age group (e.g., ages 20–24). The percentage of all births to unmarried women is the number of births occurring to unmarried women divided by the total number of births. The percentage of all births to unmarried women is affected by the birth rate for married women, the birth rate for unmarried women (who account for about 40% of all births), and the proportion of women of childbearing age who are unmarried.