Expectant mothers in the U.S. remain at a high risk for pregnancy-related death. (iStock)

Around the globe, statistics show that as education levels for women rise, fertility levels drop. Sociologist Philip Cohen puts it this way: “Women with more education have more opportunities for productive lives doing work other than childbearing.” Some conservative writers and politicians have warned ominously that this presents a “reverse Darwinism,” and a survival of the weakest.

But a new report by the Pew Research Center has found something surprising: more highly educated women in the United States are becoming mothers than ever before. And they’re having bigger families.

Childlessness among women age 40 to 44 is at its lowest point in a decade. And among the most highly educated -- women with medical degrees or PhDs -- the share of childless women has dropped from 35 percent in 1994 to 20 percent.


“That’s a stunning turnaround,” said report author Gretchen Livingston, a senior researcher at the Pew Research Center, who analyzed fertility over a woman’s lifetime in the Census Bureau’s Current Population Survey data. “It was a most surprising finding.”

Livingston attributed said the drop in childlessness was likely due to the fact that more women are highly educated than in the past and  more of them are likely to be married (since married women are more likely to become mothers). Plus, she said, advances in reproductive technology have helped the trend too.

Not only are a greater share of educated women becoming mothers, they’re also having larger families than before. The share of mothers with at least a master’s degree who have just one child fell from 28 percent to 23 percent. While those having three or more children rose from 22 percent to 27 percent.

“Of all educational groups, this was the only one that showed clear declines in small families and increases in multi-child families,” Livingston said. “I wasn’t expecting to see that at all.”

Overall, the average family size is smaller now than in the 1970s. In 1976, four in 10 mothers had had four or more children by the time they reached 40 to 44. Now, 41 percent of mothers have two children by the time they hit 44, and only 14 percent have four or more.

Women with less education, Hispanic and African American women are still less likely to be childless and more likely to have larger families than mothers with more education and white and Asian mothers.

But the childless gap between educational groups has narrowed significantly, Livingston said. Not only are highly educated women having more children, but for mothers with a high school diploma, the share having two children dropped, while those having just one child increased. Fertility patterns remain unchanged for women with bachelor’s degrees.

On the surface, the numbers may seem to contradict widely-reported data from the National Center for Health Statistics  showing that the U.S. fertility rate in 2013 was an all-time low?

But that general fertility rate, of births per 1,000 women between the ages of 15 and 44, reflects the fact that women in their 20s and 30s have delayed childbearing and there's been a slight decline in recent years in the share of women who are in their peak childbearing years.

The surprising findings could signal that as more women have become educated, workplaces are getting more used to accommodating working mothers, or that by delaying childbirth, older women have established their reputations as good workers and have more control over their schedules.

“If there are women benefitting from changing work policies, I’m guessing it would be highly educated women,” Livingston said, “And not women with less education.”

Which could explain why women with less education, who work in hourly jobs with little power or control over their schedules, are having fewer children.