Researchers from the US Centers for Disease Control and Prevention revealed in a newly released report that the national total fertility rate (TFR), an estimate of how many babies the average American woman will have, dropped for the seventh year in a row in 2017, the most recent year for which data is available.
The report, which was published Thursday, indicated that the 2017 TFR rate of 1,765.5 births per 1,000 women was 16 percent below the number needed to keep the population stable without additions through immigration. The population needs to have a TFR of 2,100 births per 1,000 women to reproduce itself without other input.
Even more concerning for researchers is that the US' total fertility rates have been steadily declining since 2010, with numbers from 2017 representing the biggest drop in recent history. In 2014, the TFR rate stood at 1,862.5; in 2015, 1,843.5; and in 2016, 1,820.5.
In reviewing data from birth certificates of all 50 US states and those of Washington, DC, researchers found that procreative habits of Americans varied across the Land of the Free. The highest TFR was detected in South Dakota, with a rate of 2,227.5 births per 1,000 women. The lowest was from the nation's capital, which averaged a TFR of 1,421.0.
When it comes to race, the highest rates were among Hispanic woman, with a TFR of 2,006.5, which was followed by black women with a rate of 1,824.5. For white women, it was 1,666.5.
Researchers also found that South Dakota and Utah, in 2017, were the only US states with a TFR that was above the 2,100 births per 1,000 women replacement level. More than 60 percent to the population of Utah are members of the Church of Jesus Christ of Latter Day Saints. A Pew Research poll from 2015 found that members of that church were more likely to be married and to have children than any other US religious group. Utah had a TFR of 2,120.5.
Although the report didn't offer an explanation for the declining numbers, experts have noted that various factors, such as increased access to birth control and women delaying having children to pursue job opportunities, are playing a role in the matter.
A July 2018 survey conducted by the Morning Consult for the New York Times found that many women put off having kids because they simply weren't able to afford child-care costs. Others surveyed noted that they just preferred having more personal freedom.
"In general, women are getting married later in life," John Rowe, a public health researcher at Columbia University, told NBC News. "They are leaving the home and launching their families later."
Another factor that has played a role in dropped fertility rates is teenage pregnancies, or lack thereof. According to the CDC, from 2006 to 2014, the teen birth rate for those aged between 15 and 19 dropped by 40 percent in that period, with teen birth rates among Hispanic and black teens falling most dramatically.
"We've been seeing, year after year, a precipitous drop in the number of births to teenage girls," Rowe said. "That's good news. Not only are these children not having children, but they're also getting a chance to finish high school. And that makes a huge difference to their lives."
This latest report comes months after the CDC published a report in May 2018 that indicated the 2017 numbers marked the lowest rate since 1978.