Nearly 10% of infants were admitted to a neonatal intensive care unit in the United States in 2023, according to a report from the National Center for Health Statistics, a 13% increase from admissions in 2016.
The report drew on birth certificate data from the National Vital Statistics System, which includes detailed demographic and health information on mothers and infants for all U.S. births each year.
In 2016, 8.7% of infants were admitted to NICUs, the report said, and that percentage grew to 9.8% in 2023. When babies are born preterm — at less than 37 full weeks of gestation — or low birth weight — under 5½ pounds — they are at least seven times more likely to be admitted to a NICU than those born later and at higher weights.
The data in the report shows that the percentage of infants admitted to a NICU increased for each age range of mothers from 2016 to 2023. Of those, babies born to mothers 40 and older were the most likely to be admitted to a NICU in 2016 (12.5%) and 2023 (13.6%), while those born to mothers 20 to 29 were the least likely to be admitted (increasing from 8 to 9% of births).
Forty states had NICU admission rates that rose from 2016 to 2023. The most marked increases, ranging from 31 to 37%, were in Alabama, Arkansas, Mississippi and New Hampshire.
“The incidence of births to older mothers and those born preterm has risen over the study period — such changes would be expected to increase the overall NICU rate,” according to the report. However, the researchers concluded, the increase was seen in births to women of all ages, not just older mothers.