A new report published by the New England Journal of Medicine reveals that an increasing number of infants suffering with neonatal abstinence syndrome are being admitted to neonatal intensive care units in the US.

According to the study's authors, neonatal abstinence syndrome is "a drug-withdrawal syndrome that most commonly occurs after in utero exposure to opioids."

The researchers found that:

"In this cohort of infants admitted to nearly 300
NICUs, we found large increases from 2004
through 2013 in the health care burden of infants
with the neonatal abstinence syndrome,
including rising admission rates for this diagnosis
and increasing length of stay. In 2013, a total
of 4% of all NICU hospital days nationwide were
attributed to the care of infants with the neonatal
abstinence syndrome, representing an increase of
6 to 7 times from 2004. This increase in NICU
utilization is consistent with multiple reports2-4
of the increasing incidence of the neonatal abstinence
syndrome in the United States. In this
large study, 23 of 213 centers reported that more
than 10% of their NICU days were attributable
to these infants in 2013, as compared with 1 of
157 centers in 2004."

Regarding the use of pharmaco-therapies for the treatment of neonatal abstinence syndrome, they report that:

"We also found that the use of pharmacotherapy
overall in these infants increased over time, with
changes in the frequencies of the use of specific
medications. In the absence of large, randomized
trials comparing medical therapies for the
neonatal abstinence syndrome, consensus is lacking regarding effective regimens; none of the medications used or recommended for use in the
management of the neonatal abstinence syndrome
are approved by the Food and Drug Administration
for this indication. Our results in this national
sample show increases in the use of clonidine
and decreases in the use of methadone; in
small studies, both agents have been associated
with a shorter length of stay than that associated
with the use of morphine."

They also found that:

"The increase in the use of the mother’s breast
milk over time in infants with the neonatal abstinence
syndrome may have occurred in response
to updated guidelines from the American College
of Obstetricians and Gynecologists, the American
Academy of Pediatrics, and the Academy of
Breastfeeding Medicine. These guidelines encourage
the selective use of breast milk in some
infants because of growing evidence that breast
milk can reduce infants’ symptoms and minimize
pharmacologic treatment, outweighing the
harm of some drug transmission, which is typically
minimal when mothers are in treatment
programs. Still, only approximately one third of
the infants in our study received breast milk in
the period from 2012 through 2013, an observation
that supports the notion that breast-feeding
remains an important target for intervention. As
in most studies of the neonatal abstinence syndrome,
we do not have information on the use
of nonpharmacologic measures to care for these

The study, published online April 26, 2015 in the New England Journal of Medicine, is titled "Increasing Incidence of the Neonatal Abstinence Syndrome in U.S. Neonatal ICUs."