A new study shows that neonatal abstinence syndrome (NAS) – the addiction and withdrawal that typically comes as a result of a pregnant mother’s use of opiate medications during pregnancy – has increased over the past decade and, that this increase is responsible for a striking rise in the health care burden of infants with the syndrome, including admission rates, length of stay in hospitals and use of resources.
The results were recently published in the New England Journal of Medicine. Karna Murthy, MD, ’11 MSCI, assistant professor in Pediatrics-Neonatology, and his team, including first author of the paper, Veeral N. Tolia, MD, ’10 GME, observed that incidence of the NAS seemed to be increasing and conducted the study to validate their clinical observations. Some of the symptoms of the syndrome in infants include damage to the spasticity of muscles, irritability, poor sucking reflexes and impaired weight gain.
“The goal of the study was to understand if the burden of NAS continued to rise even after other studies demonstrated that NAS has become a public health emergency,” Dr. Murthy said. “This issue is important because in the 1970s and 80s, this disease was thought to occur mostly in women who used illicit drugs, such as heroin, yet this disease seems to be a growing burden from women receiving prescription medication.”
The researchers analyzed data from infants with the syndrome from 2004 to 2013 in nearly 300 neonatal intensive care units (NICU) across the United States and evaluated trends in incidence and health care utilization, in addition to changes in infant and maternal clinical characteristics.
“Our data set that encompasses about 20 percent of all neonatal intensive care unit cases and admissions in the United States,” Dr. Murthy said. “One of the strengths of this study is that it represents a large portion of infants in NICUs in the United States and isn’t limited to one geographical area.”
They found the rate of NICU admissions for the syndrome rose from seven cases to 27 cases per 1000 admissions and the median length of stay in the NICU lengthened by six days. The scientists also found the total percentage of NICU days nationwide that were attributed to the syndrome increased, with eight centers reporting more than 20 percent of all NICU days were attributed to the care of infants with neonatal abstinence syndrome in 2013. The use of morphine, the most commonly administered drug for therapy for this syndrome, also increased over this time period.
“Based on our clinical observations, we were not surprised that the incidence in population and its burden in the neonatal intensive care unit was increasing, however, we were alarmed on how large these burdens on the population have risen,” Dr. Murthy said.
The authors stressed that effective strategies are needed for primary prevention of this syndrome, particularly to provide greater oversight on the misuse of the prescription medications, and postnatal treatment of infants.
“Providers and legislators have the responsibility to understand the effects of prescribing opiates in order to limit the misuse of these medications antenatally,” he said.
Next, they plan to explore the variability in NICU sites and understand why those sites have higher burdens.
“In this study we found preliminary findings to suggest that variability in the both incidence and treatment incidence between centers or NICU was striking,” Dr. Murthy said. “Some centers had more than 40 percent of their NICU days burdened by this disease and by these patients.”
