Americans are having fewer babies. There were 3,605,201 births in the U.S. last year, the lowest number since 1979.

On Wednesday, the Center for Disease Control and Prevention also announced that the birth rate fell 4% in 2020 – the sixth straight year a decline was reported.

The national birth rate is so low, that the U.S. is “below replacement levels,” meaning more people die every year than are being born, the CDC said.

“The rate dropped for moms of every major race and ethnicity, and in nearly every age group, falling to the lowest point since federal health officials started tracking it more than a century ago,” reports the Associated Press.

The decline in birth rate was particularly sharp among teens aged 15-19 – a 8% decreased from 2019.

More from the Associated Press:

The pandemic no doubt contributed to last year’s big decline, experts say. Anxiety about COVID-19 and its impact on the economy likely caused many couples to think that having a baby right then was a bad idea. But many of the 2020 pregnancies began well before the U.S. epidemic.

Indeed, December 2020 births (or March 2020 conceptions, when the pandemic began) were down 8% from the year before, suggesting that COVID-19’s impact on births has not fully manifested itself.

More context from The New York Times:

The declining birthrate is just one piece of America’s shifting demographic picture. Combined with a substantial leveling-off of immigration, and rising deaths, the country’s population over the past decade expanded at the second-slowest rate since the government started counting in the 18th century. The pandemic, which pushed the death rate higher and the birthrate even lower, appears to have deepened that trend.

The New York Times also provides insight from Caroline Sten Hartnett, a sociologist at the University of South Carolina:

That the rate has gone down is not necessarily bad, Dr. Hartnett said. One factor driving the decline is a drop in unintended pregnancies, and some people may simply be delaying childbearing to older ages. In other words, some share of American women may eventually have the number of children they want, but simply at later ages.

But Business Insider highlights the economic concerns of a low birth rate:

A decline in birth rates has sparked worries that the US may be headed for what’s known as a “demographic time bomb,” in which an aging population isn’t replaced by enough young workers. 

This could slow the economy in the long term by creating higher government costs and a smaller workforce, who will  have to front the care costs for aging populations. It could also create a shortage of pension and social security-type funds and impact things like school enrollment and college demand.