Why it matters: The data corroborates previous surveys that predicted a "COVID baby bust," with women reporting they were postponing pregnancy and having fewer children, as well surveys indicating less sexual activity overall. By the numbers: There were 55.8 births per 1,000 women aged 15 to 44 last year. It is the sixth straight year the number of births in the U.S. have fallen, CDC data shows. There was an overall decline in all age groups between 15 to 44. Brady Hamilton, the lead author of the study, called those drops "unusual" and "extraordinary." Births had been rising for women in their 30s, he said. The preterm birth rate declined for the first time since 2014 to about 10% in 2020.