Fertility rates for white women were down in every US state in 2017 - below the rate needed for the population to replace itself, a new report from the Centers for Disease Control and Prevention (CDC) reveals.
However, among black and Hispanic women, fertility rates were up in 12 and 29 states, respectively.
When researchers looked at fertility rates for women of all age groups and races, they found that the nationwide rate was 16 percent lower than what is considered the level for a population to replace itself.
Experts say this is likely due to the fact that the large proportion of native-born women are having fewer children than before, while the much smaller proportion of immigrant-born women are having more children.
Additionally, the US white population has been hit hard by the Great Recession of 08-09, and is aging.
The overall fertility rate was only above the level in two states: South Dakota (with a boom in jobs for white Americans in the energy industry) and Utah (home to a high concentration of Mormons).
Demographers and public policy experts say if the rate continues to decline, there will not be enough healthy, young workers to keep the economy going and replace an aging population.
The highest total fertility rate was in South Dakota, 57 percent greater than the lowest rate in Washington, DC. But the nationwide fertility rate was 16 percent lower than what is considered the level for a population to replace itself
Researchers looked at the birth certificates from all 50 states, including the District of Columbia and self-reported data on the mother's race from the certificate.
The highest total fertility rate was found to be in South Dakota, which was 57 percent greater than the lowest rate in Washington, DC.
No state in 2017 had a total fertility rate for white women that was above the population replacement level - what the population needs to exactly replace itself from one generation to the next.
Meanwhile, black women had a rate higher than the population replacement level in 12 states and Hispanic women had a rate that was higher in 29 states.
However across all age groups and races, the total fertility rate for the US in 2017 was 1,765.5 per 1,000 women - 16 percent below the level of a population to replace itself.
There were only two states that had rates above the population level, South Dakota and Utah.
For Utah, the answer as to why is easy: its Mormon population.
'It's certainly from Mormonism,' Dr Kenneth Johnson, a professor of sociology at the University of New Hampshire, told DailyMail.com
'The concentration for so many Mormons in a state is why the fertility tends to be higher.'
Currently, nearly 63 percent of all Utahans identify as Mormon in comparison with two percent of the US population.
According to a 2014 Pew Research Center survey, Mormons were found to have more children than other US religious groups.
Mormons between ages 40 and 59 had an average of 3.4 children in their lifetime, compared to the national average of 2.1 among all Americans
