The American baby bust

The U.S. fertility rate has reached a record low, and the total number of births in 2018 was the lowest it has been in more than 30 years, according to new data from the Centers for Disease Control.

Why it matters: The long-term economic implications of a shrinking future workforce could be dire, as Axios has reported. It's important to remember, however, these trends are also a result of progress — a falling number of teenage pregnancies, the education and empowerment of women, more accessible birth control, and lower child mortality rates, demographers say.

By the numbers: While birth rates fell for younger women in 2018, they rose slightly for women in their late 30s and early 40s, according to the newest CDC data. Women waiting longer to start their families has been a growing, global trend.

• The total fertility rate, the number of babies a woman of childbearing age is expected to have over her lifetime, is currently at 1.72 — 2% lower than in 2017. It's also notably below the 2.1 fertility rate required for one generation to perfectly replace the next.

Between the lines: The U.S.' high levels of immigration have helped buoy the population. It's a key reason the U.S. is in a better place than other nations with falling fertility rates that are beginning to see the impact on their societies and economies, such as Japan, Hungary and Spain.

• But immigration might not always be enough to fully compensate for low fertility rates, Global Aging Institute president Richard Jackson and sociology professor Irene Bloemraad from University of California Berkeley told Axios last year.

The big picture People are living longer, growing up slower and delaying marriage, but when it comes to fertility, there is a biological clock. As women wait longer to have kids, they tend to have fewer of them, demographers have told Axios. These demographic realities are changing the way we live our lives and could ultimately lead to slowed economic growth as the costs for caring for a large, elderly generation fall on a smaller young workforce.

Go deeper:

• How we arrived at a aging, childless future
• Special report: The aging, childless future
• People around the world are waiting longer to have kids
• The new rite of passage: Young, busy and still single