According to 2019 data from the Centers for Disease Control and Prevention the preterm birth rate in the United States was approximately 10.23%. This means that about 1 in 10 babies in the U.S. was born prematurely, before completing 37 weeks of gestation. The average age of USA women when they deliver their first baby is 27 years old. Twenty seven years ago the average age of first-time mothers in the USA was 24 years old.