The pace of babies born each year in the U.S. has slowed to a new record low, according to an analysis of 2023 birth certificate data published Thursday by the Centers for Disease Control and Prevention. 

Last year’s slowdown marks an official end to the uptick in new babies that began during the COVID-19 pandemic. At least 3,591,328 babies were born in the U.S. in 2023, down 2% from the 3,667,758 born in 2022. 

This is on par with annual declines seen before the pandemic, the report said, which averaged around 2% fewer babies each year.

There were already signs in the year before that a pandemic surge in births was coming to an end. There were slightly fewer babies born in 2022 compared to 2021, though agency officials said at the time that this drop was not large enough to be considered a statistically significant decline.

“Last year, the difference was very small. This year, it’s something on the order of 74,000 or thereabouts. So it’s fairly large,” the CDC’s Brady Hamilton, one of the report’s authors, told CBS News. 

While records for nearly 100% of registered births have already been reported to the agency, the report’s estimates remain “provisional estimates” until the last remaining data is reported in. 

Thursday’s new report by CDC’s National Center for Health Statistics comes from closely watched data on birth certificates that the agency collects from state and local authorities throughout the year. The report was released earlier this year. Last year’s provisional report did not come out until June.

“We got started early and kept up the momentum, and this is how we managed to get this early release,” said Hamilton.

Total fertility rate falls

Last year’s total of new births adds up to a rate of 1,616.5 births per 1,000 women in the U.S. This figure, called the total fertility rate, calculates the average number of births that women will have over their lifetimes if current rates stay the same.

Unless the U.S. reaches 2,100 births per 1,000 — which works out to an average of 2.1 children per woman — the total population could shrink without other influxes of people. U.S. Census Bureau estimates have chalked up recent population growth to rebounding immigration and a drop in deaths. 

The U.S. total fertility rate has been below what is needed to replace deaths of previous generations since 1971. 

“Think about that in terms of the woman and her partner. So if you have a total fertility rate of two, you’re replacing him and you’re replacing her in the population. It has to be 2.1 to compensate for mortality,” said Hamilton.

The number of new births in 2023 was flat or declined from 2022 for most groups except Hispanic women, who saw an increase of 1%. 

Teen birth rates plateau

Birth rates by age group were also down or unchanged from 2022 to 2023 for virtually all women, young and old. This includes women ages 40 to 44 years old, who had previously seen the pace of new babies born rise for almost every year since 1985.

However, a once plummeting rate of teen births has gradually flattened in recent years, falling 3% from 2022 to 2023. For every 1,000 female teens ages 15 to 19 years old, 13.2 births were reported. 

“It’s important to remember that if you look at the years prior to that, 2007 to 2022, the rate for teen births 15 to 19 was declining by 7% on average. And now it’s declining by 2 and 3%. So the question is why,” said Hamilton.

“We need to look into finding out why it’s only declining half of what it has been doing, and it could be a number of factors. There’s a lot to be investigated and pieced out.”

The decline was smallest among younger teens, ages 15 to 17 years old, whose birth rate was virtually unchanged from 2022.

Cesarean deliveries increase again

According to the CDC’s new report, 32.4% of new births were cesarean deliveries in 2023, up from 32.1% in 2022’s figures. 

This marks the fourth increase in a row in the rate of C-sections in the wake of the pandemic, after rates had slowed from 2009 through 2019.

Cesarean delivery rates are highest among Black moms, climbing to 37% last year. Rates also inched up for Asian, White and Hispanic women. 

Among low-risk births, cesarean deliveries have climbed to 26.6%. Low-risk deliveries are defined as head-first births of single babies at full term, at least 37 weeks in, to moms who have never had children before. 

This is the highest rate since 2013, the report says.