The number of births in the United States fell by 2% in 2023, driven in part by a marked birth rate decline among older teenagers and women aged 20-24. The birth rate in 2022 was flat with the prior year. Among women aged 25-34 years, who accounted for more than 2 million births in 2023, the birth rate fell about 2.5%, while births among women aged 20-24 years fell by 4% to a record low rate. U.S. birth rates for teenagers aged 18-19 years fell 3%, also a record low, while the rate among teenagers aged 15-17 years was flat. Teen births have been falling since 2007. Births declined for all races except Native Hawaiian and Pacific Islander women, for whom the number of births was basically flat. Black and Native American women experienced the largest birth declines, by 4% and 5%, respectively. For women of Hispanic origin, births rose by 1%. There was an uptick in deliveries by cesarean section last year, tracking with the rising average age of mothers. The rate of infants delivered by cesarean section rose moderately for the fourth-consecutive year to 32.4%, the highest since 2013, up from 32.1% in 2022.