The fertility rate in the United States fell to an all-time low last year. Americans' average life expectancy, meanwhile, sits at a relatively high 78.7 years.
Many experts say the 2008 economic recession and high college tuition are contributing to this trend.
According to a 2018 survey in The New York Times, however, adults who want kids say they sometimes end up having few, or zero, kids due to the high cost of childcare. The average cost of full-time childcare exceeds $10,000 a year in several states, according to Child Care Aware of America.
The US birth rate has remained below "replacement level" since the 1970s, which means not enough children are being born to keep the population at a steady level.
Last year, the US Census Bureau wrote in a paper that women who have kids between the ages of 25 and 35 have more difficulty in getting fair pay than women who give birth outside of that range. American women are now having children older than ever.
The ratio of retired citizens to working Americans keeps increasing, though the number of immigrant workers is going up as well.