SALT LAKE CITY — Call them the wed states: Utah, Idaho and Colorado.
These are the states that, in 2018, had the fewest babies born to unwed mothers — or, as the National Center for Health Statistics calls them, nonmarital births.
Utah, Idaho and Colorado are anomalies in a nation where the number of out-of-wedlock births hovers around 40%.

In every other state, 30% or more of babies born in 2018 had unwed mothers; in some states, more than half did. Mississippi, for example, leads the nation in births to unmarried women with 54%.
In contrast, 19.2% of births in Utah were to unmarried women, with 23.2% in Colorado and 27% in Idaho.
The numbers in Utah and Idaho can be partially explained by religious faith. Both states are heavily populated by members of The Church of Jesus Christ of Latter-day Saints, which emphasizes the importance and sanctity of marriage.
But what’s going on in Colorado? In 2016, a Pew Research Center report ranked Colorado among the 10 least religious states.
While there are no definitive answers, Colorado’s numbers likely derive from multiple moving parts, including a significant reduction in teen pregnancy over the past 10 years and a trend of educated women delaying childbirth, sociologists said.
States with the highest numbers of married moms also follow established demographic trends, said W. Bradford Wilcox, a sociologist at the University of Virginia and director of the National Marriage Project. “Both culture and class account for these state differences in nonmarital childbearing,” Wilcox said.
Regardless of the cause, the government’s report provides the latest evidence of a significant reshaping of child bearing in the U.S., as the birth rate continues to fall. The birth rate fell 2% in 2018 and has declined every year but one since 2004, the NCHS said. So even as Americans are having fewer children, more than a third of them are born to parents who aren’t married, which some researchers say gives children a disadvantage.
‘Family-planning miracle’?
A 2% decline doesn’t sound like much, but in a nation as big as the U.S, that number represents a lot of lives; 63,788 fewer babies were born in 2018 than in 2017, the government report said.
Part of the reason for the overall decline is a marked drop in births to teens, which is also a factor in nonmarital birth numbers, said Anne Driscoll, a demographer with the federal Division of Vital Statistics and co-author of the report.
“Almost all teen births now are nonmarital births. That didn’t use to be true in the past” because of changing cultural norms that frown on teen marriage, Driscoll said. “Because teen births, over time, are down pretty drastically and pretty steadily, they’re a smaller and smaller proportion of births and therefore have a smaller and smaller effect on the overall birth rate. It’s two moving pieces together, in a sense.”
Since the National Campaign to Prevent Teen Pregnancy began in the 1990s, teen pregnancy has fallen by more than 70%, and those numbers are still in decline.
They also help to explain why the number of children born to unmarried women has marginally declined each year since its peak at 41% in 2009. The percentage of all nonmarital births was 39.6% in 2018, down from 39.8 % in 2017.
The numbers are intertwined, Driscoll said, but don’t account for all of the changes. Even as fewer teens are having babies, many young women are waiting to have children until they are economically and professionally secure, and they are more likely to be married in their 30s than at younger ages, she said.
Colorado, specifically, had one of the largest declines in teen pregnancies in the U.S. beginning in 2009, according to Elizabeth Garner, Colorado’s state demographer. That year, she said, 3,300 unmarried teens in Colorado got pregnant; the number was 1,874 in 2017.
One reason could be Colorado’s pioneering program that provides low- or no-cost, long-acting contraception, aided in part by a $28 million gift by an anonymous donor in 2008. The state saw not only a decline in teen births, but also in abortion, in what the nonprofit Sightline Institute called a “family-planning miracle.”
Money matters
However, there’s more going on here besides improved access to birth control. Education, income disparity and demographics also help to explain the findings.
Karen Benjamin Guzzo, a demographer and sociology professor at Bowling Green State University in Ohio, said that Colorado’s position between Utah and Idaho is likely a reflection of economics, since money, or lack thereof, is a driver in decisions about when to get married or have a child.
“Colorado is a state that tends to be well-off and more educated, and people are waiting until their late 20s, on average, to have kids, whereas people in the deep South tend to have kids earlier,” she said. “All things being equal, the earlier you have your kids, the less likely you’re going to be married when you have your kids.”
New Mexico, conversely, which is among three states where more than half of births are to unwed mothers (51.2%), has a smaller percentage of residents (27%) with a bachelor’s degree or higher than the national average. And nearly 20% of its residents live in poverty, compared to fewer than 10% in Colorado.
“When states do not have great economies, people don’t get married but they also don’t see a lot of reason to hold off on having kids,” Guzzo said. “In places where things look pretty bleak, people tend to think, ‘Well, at least I can have kids.’ They’re not waiting for the mythical finish college, get my degree, get a great job, get a great house; those things materialize less often. So there’s less reason to hold off.”
At the same time, states with the highest rates of children born to unmarried women tend to have greater populations of African Americans, Hispanics and Native Americans, said Wilcox with the National Marriage Project. Nonmarital births are generally less frequent among whites, Asians and immigrants.
Because data about ethnicity, income and access to education is often interrelated, it is difficult to isolate the role each factor plays.
Colorado was 87% white in 2018, according to the U.S. Census Bureau, and nearly 40% of its residents had a bachelor’s degree or higher, compared to 33% of Americans nationwide.
Disadvantaged from birth?
Diverse research has shown that children of married parents fare better than those living in single-parent homes. “That’s because marriage itself fosters higher income and better parenting among today’s parents,” Wilcox has written. “For instance, men who get and stay married work longer hours and make more money than their unmarried peers. And fathers and mothers who are in an intact marriage tend to engage in more involved, affectionate, and consistent parenting than their peers in single- or step-families.”
However, Guzzo notes that the government only knows if parents are married or unmarried, not if the parents are in a committed relationship.
And cohabitation is on the rise; in fact, for those ages 18-24, it’s now more prevalent than living with a spouse, according to the Census Bureau.
“Now, we know that (cohabitating relationships) are less stable, but it doesn’t mean it’s a teenage mom coming home and living by herself or with her parents. It’s often a 22-year-old living with her boyfriend. Nonmarital or unwed doesn’t mean unpartnered or totally single,” Guzzo said.
But, Wilcox at the University of Virginia noted, the numbers show more than a third of the nation’s babies — more than half in New Mexico, Louisiana and Mississippi — are at risk for unstable home lives.
“It’s true that a majority of kids born outside of marriage are born to cohabiting couples, but they’re less likely to be planned, and they’re twice as likely to break up than married relationships. It’s still the case that they are more likely to experience instability and single parenthood than kids born to married parents,” he said.