The number of babies born in the U.S. in 2018 fell to the lowest level in 32 years, according to a government report released Wednesday.

The numbers are part of a decadeslong trend toward fewer and fewer babies being born each year — which means we’re getting further away from the possibility of having enough children to replace ourselves, according to the report from the Centers for Disease Control and Prevention.

“The major finding is that the fertility rates are reaching record lows,” said the report’s lead author, Brady Hamilton, a statistician and demographer at the CDC’s National Center for Health Statistics. “There have been record lows in the teenage birth rate, which fell 7 percent compared to 2017.”

Hamilton and his colleagues found that the total number of births in 2018, at 3,788,235, was down 2 percent from 2017. The general fertility rate for 2018 was 59.0 births per 1,000 women aged 15 to 44, another record low for the U.S.

For perspective, it’s lower than in the years after the Great Depression. In 1936, for example, the general fertility rate was 75.6.

More telling, perhaps, is the drop in the “total fertility rate,” which also fell 2 percent compared to 2017 figures, to 1,728 births per 1,000 women of childbearing age.

For the nation’s population to reproduce itself at current numbers and remain stable, the total fertility rate would need to be at least 2,100 births per 1,000 women. So, essentially, for the population to remain stable, each woman needs to have at least two babies. At 2,000 there would be enough children to replace fathers and mothers. The extra 100 is to account for deaths.

Teen births at record low

The CDC research doesn't explain why birth rates are declining, Hamilton said.

There was some good news in the new report: Fewer babies are being born to teens. In fact, “these are record lows for teenage birth rates,” Hamilton said. “This year’s rate is 7 percent lower than in 2017.”

Overall, the report finds that younger women are having fewer babies, with the only demographic seeing an increase in birth rates is women in their late 30s and early 40s.

The patterns seen in the U.S. echo what’s been happening in many developed countries, said Dr. John W. Rowe, a professor at Columbia University Mailman School of Public Health. “For comparison, the total fertility rate in Europe is 1.58, in Southern Europe, meaning Spain and Italy, it’s 1.3, and in Japan, it’s 1.44,” Rowe said. “So this is not unprecedented.”

There are some serious implications that could result from the declining birth rates, Rowe said. “Long term it means we’re going to have an increasing proportion of older people,” he added. “All the projections about what percent of the population will be elderly in 5, 10, 20 years from now were made with the assumption that the birth rate would be stable.”

The lowered birthrate will “have a significant impact on the labor force,” Rowe said.

Delaying marriage and childbirth

Japan in particular is having issues related to declining birthrates because of its immigration policies, Rowe said. “They don’t have an adequate workforce to take care of a very large elderly population,” he explained. “It’s a real challenge for them.”

Studies have shown that women are delaying both marriage and childbirth, said Donna Strobino, professor and chair of education, population, family and reproductive health at the Johns Hopkins Bloomberg School of Public Health. “We’re clearly in the throes of major social change with regard to women getting married and choosing to have children,” she added. “There’s no question that part of the explanation for that is economic. It’s very expensive to raise children these days. And in part it’s social — all the changes in women’s roles.”

Still, there are hints in the new report that the current trend could at least partially reverse itself, said Strobino. “It’s perhaps not as gloom and doom as some think it is,” Strobino said.

She points to the increase in the number of babies being born to women in their late 30s and early 40s, which she sees as a possible sign that the fertility rate could recover eventually. It's possible that women who have been postponing pregnancy may have the babies they were planning to have and that could reverse the trend.

Maybe, says Dr. Helen Kim. But maybe not.

“As a fertility specialist, I worry that delaying childbearing will result in more fertility problems,” said Kim, an associate professor at Northwestern University’s Feinberg School of Medicine.

Fertility — particularly women’s fertility — declines with age.

"I have seen numerous couples who have waited too long," said Kim. "Some have been married for more than 10 years before they think about having kids. There have been many advances in fertility treatment, but there is still no treatment for reproductive aging.”