On opposite ends of Greater Houston, women in two of the region’s two largest suburban counties are taking different approaches to childbearing.
In Fort Bend County, women were on track to have an average of 1.5 children during their lifetimes as of 2024, a total fertility rate well under the state average and the lowest in the Houston region. Most children in Fort Bend County are born to mothers in their 30s, as women increasingly delay having children.
To the north, in Montgomery County, the total fertility rate stands at 1.9 children per woman, down from two decades ago but still above the state average and the highest rate in the region. A slight majority of women in the county are giving birth in their 20s.
These dynamics, outlined in a new Kinder Institute for Urban Research report documenting 20 years of regional fertility trends, figure to shape growth in two of the region’s booming suburban counties for years to come. The difference in fertility rates equates to tens of thousands more children born in Montgomery County compared to Fort Bend County over the course of decades, with numerous implications for civic life.
“While the difference between 1.5 and 1.9 might not look dramatic at first glance, over the long term, Fort Bend will experience much slower natural growth — or a faster shift toward overall contraction — because 1.5 is significantly lower,” said Karen Goolsby, a researcher in the Kinder Institute’s Houston Population Research Center.
To date, the divergent fertility rates haven’t stopped rapid growth in either county, both of which have seen their population more than double over the past two decades. Tens of thousands more people continue to move into Fort Bend and Montgomery counties than move out each year, with many drawn to the allure of lower-cost housing and a suburban lifestyle.
But if movement into either county significantly slows, population growth could taper off or the resident count could decline. To keep populations stable in the absence of net-positive migration, total fertility rates must stay above 2.1 births per woman, a figure known as the fertility replacement rate.
Already, lower fertility is also beginning to factor into decisions about how fast-growing communities plan for the future. Fort Bend ISD, for example, voted in March to close seven elementary schools amid declining enrollment, which district leaders partially attributed to falling birth rates.
Differences behind the declines
Fertility rates in the U.S. have been falling for nearly two decades, a phenomenon that researchers attribute to multiple factors. They include changing cultural priorities, a sharp decline in teenage pregnancy, affordability concerns and burdensome student debt.
Those trends held true in five Houston-area counties analyzed by the Kinder Institute: Brazoria, Fort Bend, Galveston, Harris and Montgomery. Total fertility rates, which measure the average number of children a woman would have over her lifetime if current age-specific fertility rates remained constant, fell from roughly 2.3 in 2003 to 1.7 in 2024.
But while fertility rates declined across the region, the pace varied by county.
In Fort Bend County, the fertility rate fell 28.6%, from about 2.1 to 1.5 births per woman. Montgomery County recorded the smallest decline in the region at 17.4%, dropping from 2.3 to 1.9 births per woman.
Kinder Institute researchers said differences in age structure, migrant population composition and racial and ethnic demographics, among other factors, can contribute to variations in fertility patterns.
“It depends heavily on each county’s local characteristics, economy and healthcare infrastructure,” Goolsby said.
In Fort Bend and Montgomery counties, some of the clearest differences emerged when analyzing fertility by age.
Fertility rates plummeted in Fort Bend County among women in their 20s, with 53 fewer births per 1,000 women in 2024 compared to 2003 among women ages 20 to 24 and 60 fewer births per 1,000 women ages 25 to 29. At the same time, fertility rates ticked higher among Fort Bend County women in their 30s and early 40s.
Montgomery County also saw a steep decline in women in their 20s having children, but the rate only fell by 20 births per 1,000 women ages 25 to 29. Fertility among Montgomery County women in their 30s and early 40s grew at a roughly similar pace as Fort Bend County.
Kinder Institute researchers could not determine from the data whether women giving birth at older ages were having their first child or an additional child, Goolsby said. But delaying childbearing leaves less time to have subsequent children.
What fewer births could mean
For now, Houston remains in growth mode.
While fertility has fallen below the replacement rate in both counties, migration has driven population booms. Fort Bend County has added about 560,000 residents since 2003, while Montgomery County’s population is up about 440,000.
The two counties each saw about 8,000 to 9,000 children born annually over the past several years, while net migration totaled about 20,000 to 30,000 annually.
Still, continued declines in fertility would have multiple consequences for the region, potentially slowing population growth and resulting in an older average population.
Such changes would affect school enrollment, particularly in Fort Bend and Montgomery County districts that have rapidly built over the past few decades to accommodate tens of thousands of additional children. Already, several large districts have seen notable slowdowns in student population growth over the past few years, including Katy, Fort Bend and Tomball ISDs.
Demand for maternal and pediatric healthcare services would shift, prompting a reallocation of resources by medical providers.
Goolsby said continued declines in fertility rates could impact the need for services at both ends of the age spectrum.
“Houston may need to plan for increased demand for geriatric medicine, chronic disease management, home healthcare, rehab, assisted living and long-term care,” she said.
“At the same time, if policymakers want Houston to attract young families, affordable childcare that allows women to have the same opportunities in the labor force becomes important. These are details that affect the decision to become parents.”
