Why when a mother has her last child matters

Bowling Green State researchers look at when women are having their last babies and the challenges, benefits of being an older mom

Talk about pregnancy and fertility often centers on how old a woman is when she begins having children and how many she intends to have. There’s less discussion on the other end of the female reproductive cycle: the age at which a woman has her last child.

Researchers at Bowling Green State University in Ohio decided to take a close look at that, given the falling fertility rate in the United States and much of the rest of the world, which has ramifications beyond an immediate household.

The beginning and the ending of having children are tied together in ways that shape the future economy, a woman’s ability to have the number of children she wants, the coming workforce and even whether neighborhoods build or shutters schools. Questions of maturity and resources — not all financial — come into play. And this particular landscape has been changing for many years.

For individual families, the story is very personal.

“As we shift around when people have kids and under what circumstances, it probably has a big effect on how long people are in their intensive childbearing years and how long they’re parenting and at what point parenting overlaps with other roles that they have,” said Karen Benjamin Guzzo, acting director of the Center for Family & Demographic Research and a sociology professor at Bowling Green State. She conducted the study with graduate research associate Lisa Carlson.

They looked at women nearing the end of their childbearing years, ages 45-49 years old, to see when they last had a child. They found the median age of last birth was 31, though it varied some by race and ethnicity. Hispanic women and those classified as “other” gave birth at the oldest median age, 32, while the youngest median age was 30 for Black women.

They also found that women who had at least a bachelor’s degree were older on average than less educated women when they had their last child — no surprise, as educated women are waiting longer to have a first child, too, compared to those with less schooling.

“This report highlights the age increase shift in the median age of mothers at last birth. We know that women are delaying the age at first birth. This trend results in delays in all subsequent births, including the final one. We also know that women are having fewer children — total fertility rates are declining,” said Pamela S. Perlich, director of demographic research at the University of Utah’s Kem C. Gardner Policy Institute.

“Delays in childbearing generally are also associated with declines in completed fertility. Increases in mothers’ median age at first birth delays the age for all of their subsequent births. This, in turn, results ultimately in smaller family sizes,” she said.

An average age of 32 sounds fairly young, but Guzzo emphasizes that includes women who are pushing the edge of their reproductive years at both the beginning and the end.

“You can push when you start having kids back for a long time, but you have to stop eventually,” Guzzo said. “So if you don’t start having your first kid until 35 or 40, you don’t have a lot of time to have more kids.”

Pandemic decrease

America’s fertility rate is well below the replacement rate of 2.1 children per woman of childbearing years, true even in states with relatively larger families, like Utah. And the decrease in fertility has been happening for a long time, though events like the recession and the pandemic have accelerated the expected decrease in births recently.

Melissa S. Kearney, an economics professor at the University of Maryland, and Phillip B. Levine, an economics professor at Wellesley College, last year predicted a pandemic-related baby bust. And they updated their projection this week in The New York Times: 300,000 fewer births than usual in 2021.

Quora calculates that the average American high school has 752 students, so about 400 fewer high schools would be needed in about 15 years unless the declining birth rate is offset by an increase or a long-held trend reverses. Add a few years and we might need fewer colleges, but more skilled workers, to keep the economy humming. Experts also say if the trend continues, working-age adults could struggle to shoulder the cost of social programs for both young and old alike.

A survey by the Guttmacher Institute found that one-third of women said they decided to delay having children or to have fewer children than they’d planned because of the pandemic and related pressures. That decision was more likely in women who were financially worse off as a result of the pandemic.

What does the declining U.S. fertility rate say about housing sales, Social Security and college?
What does the declining U.S. fertility rate say about housing sales, Social Security and college?

Kearney and Levine wrote their prediction “was based largely on the fact that economic factors affect people’s decisions about whether and when to have a baby.” While the decrease might be temporary, “many of the missing COVID births will be lost forever,” they said.

Changing family life

The story will ultimately unfold differently for every woman, but there are different potential consequences to having children young and to having them when one is older. Guzzo thinks the trend to older moms has pluses and minuses — like more resources and maturity, but greater likelihood of being sandwiched between raising kids and helping older parents.

Kearney and Levine highlight the positive possibility that the smaller cohort from the pandemic will enjoy smaller class sizes and maybe less competition to get into college or find jobs. But they add some of them will grow up without brothers and sisters they might otherwise have had.

Having children when you’re older also means someone pushes back the age when they’re actively raising children. “We are going to see a lot more people who are going to butt up against being in their important career stages,” said Guzzo, who points out many people flourish in careers during their 40s and 50s, which might be harder if they have more child-related needs then, too. And a lot at that stage also juggle responsibility to help their aging parents more.

“So we might start to see more people in that sandwich generation, people who are caring for their parents but still have younger children that they are responsible for,” she said. “And we just don’t really think about the end of the childbearing years very often.”

Guzzo is quick to point out there’s nothing wrong with choosing to be an older parent, but she thinks people should take a look down the road. “You might be a more mature parent at 50 with an 11-year old than you might be at 30 with an 11-year old. The point is there are different life stages — and we haven’t really given a lot of thought to what that means to be parenting at later ages,” she said.

She also notes a difference in what the parents of older parents can do to help out — or in what help they’ll need. A grandparent who’s 50 might be more willing to babysit or more able to provide other resources than a grandparent who’s 70 or older. And, she added, “I think we’ll probably see an increase in people who are having some of those sandwich generation issues where they need to help out their parents.”

Pro-birth policies that make it easier for families to raise children could make a difference, according to Kearney and Levine. And immigration can — and already has — shored up the U.S. population, “which brings its own political and social challenges.”

Lyman Stone, a scholar at the Institute for Family Studies, recently told the Deseret News that immigration is likely to be of limited help, though, since it hinges on people wanting to come here. He asked: What happens if fewer people leave their own countries or if they decide to go somewhere besides the United States?

Many countries face similar issues. A multicountry study in Population and Development Review from investigators at Vienna University of Economics and Business found people worldwide “now challenging the natural fertility barriers, particularly for a first child,” including having babies in their late 40s or even early 50s.