MONDAY, March 18 (HealthDay News) -- Nurse understaffing is widespread in U.S. neonatal intensive care units (NICUs) and linked with higher rates of infection, a new study indicates.

Researchers looked at data from more than 11,000 infants with very low birth weights who spent at least three days in NICUs in the United States in 2008 and 2009. They also examined data on NICU staffing levels of registered nurses.

Nurse understaffing occurred for 32 percent of all infants in NICUs and for 85 percent of infants who required higher levels of care, according to the study published online March 18 in the journal JAMA Pediatrics.

On average, meeting minimum national staffing guidelines would require an additional 0.11 of a nurse per infant overall and an additional 0.39 of a nurse for each infant requiring a higher level of care, said Jeannette Rogowski, of the University of Medicine and Dentistry of New Jersey, Piscataway, and colleagues in a journal news release.

The study also found that infection rates for very low birth weight infants in NICUs were 16.5 percent in 2008 and 13.9 percent in 2009. The higher the levels of understaffing, the greater the risk of infection. While this study showed an association between nurse staffing in NICUs and infant infections, it did not prove a cause-and-effect link.

More information

The Nemours Foundation has more about neonatal intensive care units.