Over the last 30 years, U.S. growth in neonatal intensive care unit (NICU) capacity was not associated with lower infant mortality.
Total adjusted neonatologists and NICU beds per 1,000 live births increased 227% and 48%, respectively, while neonatal mortality (<28 days) and 180-day mortality decreased.
However, there was no meaningful correlation between change in regional capacity and change in neonatal mortality.
Rising neonatal intensive care unit (NICU) capacity was not tied to lower infant mortality, a large cross-sectional study in the U.S. suggested.
From 1991 to 2020, total adjusted neonatologists per 1,000 live births increased 227%, from 0.44 to 1.44, while NICU beds per 1,000 live births rose 48%, from 5.43 to 8.02, respectively, reported researchers led by Gwenyth Gasper, MS, of the Geisel School of Medicine at Dartmouth in Hanover, New Hampshire.
Over the same period, neonatal mortality before 28 days of age and 180-day mortality decreased 43% (from 3.87 to 2.21) and 49% (from 6.27 to 3.19), respectively, the group noted in JAMA Pediatrics.
However, there was no meaningful correlation between change in neonatal mortality and change in regional capacity, whether measured by number of neonatologists available (r −0.12, 95% CI −0.25 to 0.00) or NICU beds (r −0.07, 95% CI −0.19 to 0.06).
"Despite the number of practicing neonatologists almost doubling and a nearly 50% increase in the total number of available NICU beds from 1991 to 2020, newborn mortality was not lower in regions with higher growth of NICUs," Gasper told MedPage Today in an email. "That is, increased numbers of NICU beds and NICU doctors over the past 30 years had no effect on the risk of newborn death."
"During this period, newborn mortality did decrease, but this was likely due to better care, not greater NICU supply," Gasper added.
Raising NICU capacity has been presumed to improve outcomes by increasing NICU admissions and NICU days and boosting specialized hospital resources and clinician time for seriously ill infants, her group noted.
However, given the findings suggesting that the increase has not been driven by need, there could be actually negative impacts ranging from misallocation of resources to "providing newborns with more intensive care than they need," the researchers added.
"Competition between a higher number of NICUs concurrent with a constant or declining birth population increases the chance of overuse, particularly when there is substantial scientific uncertainty in what constitutes effective care in newborns with greater than 32 weeks' gestation," Gasper and colleagues wrote. "Given the potential adverse effects of unnecessary NICU admissions to newborns and parents, slowing NICU expansion and using NICUs more selectively may be an important frontier of improving newborn care, requiring collaboration between clinicians, health systems, training programs, and healthcare regulators."
Further growth in capacity likely wouldn't do as much good as "alternative strategies, such as the development of new technologies and more complete implementation of care models known to be highly effective," the group noted.
For the study, the researchers looked at a 25% sample of all U.S. infants born live with a birthweight of at least 400 grams and gestational age of between 22 and 45 weeks. The association between change in regional capacity and mortality was estimated in the years 1991, 2003, 2007, 2012, 2017, 2018, 2019, and 2020 using designations of 246 NICU regions that didn't change over this period.
The primary finding was also true for newborns of higher health risk, including those born preterm, at a very low birthweight, or to mothers of a racial or ethnic minority.
Additionally, in multilevel models adjusted for maternal and newborn characteristics, neonatal mortality was not associated with changes in capacity in terms of either number of available neonatologists (adjusted relative rate [aRR] 1.02, 95% CI 0.94-1.10) or NICU beds (aRR 0.99, 95% CI 0.987-1.004).
Nor was 180-day mortality meaningfully associated with changes in capacity in terms of neonatologists (aRR 1.00, 95% CI 0.94-1.07) or NICU beds (aRR 0.99, 95% CI 0.98-0.99).
Limitations included that "accurate measurement of NICU capacity at a national scale is imperfect," Gasper and colleagues noted, and that there was likely an underestimation of NICU providers nationwide.
Furthermore, there were differences in the methods used to determine gestational age from 1991 to 2020, they added. And the study only assessed newborn mortality.
"While studies are also needed to examine the association between capacity and utilization with outcomes other than death, we should also take a critical look at the direction of NICU investments," Gasper said. "It appears that better newborn outcomes will come from better care, but perhaps not from more NICUs and more NICU doctors than we have today."
author['full_name']
Jennifer Henderson joined MedPage Today as an enterprise and investigative writer in Jan. 2021. She has covered the healthcare industry in NYC, life sciences and the business of law, among other areas.
Disclosures
The Kettering Family Foundation and the U.S. National Institute for Child Health and Human Development (NICHD) provided study funding. A co-author reported receiving grants from the NICHD during the conduct of the study.
Primary Source
JAMA Pediatrics
Source Reference: Gasper GM, et al "Regional growth in US neonatal intensive care capacity and mortality, 1991-2020" JAMA Pediatr 2025; DOI: 10.1001/jamapediatrics.2024.7133.