Disparities exist in how babies of different racial and ethnic origins are treated in California’s neonatal intensive care units, but this could be changed, say Stanford researchers.

Infants’ racial and ethnic identities influence the quality of medical care they receive in California’s neonatal intensive care units, a study from the Stanford University School of Medicine has found.

The study, which examined medical care of more than 18,000 of the state’s smallest babies at 134 California hospitals, was published Aug. 28 in the journal Pediatrics.

The disparities were not uniform: At some California hospitals, infants from vulnerable populations received worse care than white infants, while at others, they received better care than whites. In general, however, the hospitals with the best outcomes for their patients also delivered better care to white infants. In addition, the study found that black and Hispanic infants were more likely than white infants to receive care in poor-quality NICUs.

“There’s a long history of disparity in health care delivery, and our study shows that the NICU is really no different,” said the study’s senior author, Jochen Profit, MD, associate professor of pediatrics. “Unconscious social biases that we all have can make their way into the NICU. We would like to encourage NICU caregivers to think about how these disparities play out in their own units and how they can be reduced.”

The study used data from the California Perinatal Quality Care Collaborative, which has collected information on 95 percent of premature births in the state. The study included 18,616 babies whose birth weights were less than 3.3 pounds, a category known as very low birth weight, and who were born between the beginning of 2010 and the end 2014. The research excluded infants born extremely premature (before 24 weeks of pregnancy), those who died before 12 hours of age and those with severe congenital abnormalities.

Profit and his colleagues used an index they had previously developed and validated to measure NICU care. To use the index, called Baby-MONITOR, each infant’s medical records are evaluated and scored on nine yes-or-no questions, all of which have been shown in prior research to reflect the quality of medical care. Some questions assess whether patients received aspects of NICU care that are in keeping with standard medical practices for premature babies, such as being examined for an eye disease called retinopathy of prematurity, or receiving steroids before birth to help mature their lungs. Other questions assess specific medical outcomes, such as experiencing a hospital-acquired infection or growing at a healthy rate. All questions are worded such that better outcomes produce higher scores.

The analysis then adjusts scores to account for the length of the mother’s pregnancy, whether the mother received prenatal care, whether the baby was from a single or multiple birth, the baby’s 5-minute Apgar score (a quick assessment of the infant’s physical health at birth) and whether delivery was by cesarean section.

Scores were also statistically adjusted to reflect the fact that some hospitals cared for sicker babies, on average, than others. The final score for each hospital, and for each group of patients within a hospital, reflects whether the hospital did the same, better or worse than would be expected in addressing their patients’ medical problems. Scores were calculated separately for white, black, Hispanic, Asian and “other” infants and referenced for each subgroup against whites.

When researchers analyzed the population of very low birth weight infants in their study, Hispanic infants and those with “other” ethnicity had lower Baby-MONITOR scores than white infants, while black and Asian infants did not have significantly different scores than whites. However, across the state, white infants scored higher on measures of whether sta