Clinical Trial to Decrease Length of Stay in Infants With Neonatal Abstinence Syndrome With an Exclusive Human Milk Diet

Inclusion Criteria: 1. Term infants (≥37 and 0/7 weeks gestational age) ≤ 2 days old with a diagnosis or at risk for neonatal abstinence syndrome. Can be enrolled ante-natally. 2. Infant feeding was NPO (nil per os) or consisted of 100% human milk diet prior to randomization. 3. Parent(s) willing to sign informed consent. 4. Parent(s) willing to comply with study follow-up procedures. Exclusion Criteria: 1. Term infants \>2 days old at the time of evaluation for NAS. 2. \<37 weeks gestation. 3. Outborn infants who received enteral nutrition at the other institution prior to transfer. If it is uncertain if infant received even 1 bottle or a small amount of formula, infants will be excluded. 4. Major congenital abnormalities: 1. Confirmed or suspected major genetic abnormalities (lethal or with extremely low probability for survival). 2. Chromosomal abnormalities: Trisomies (13, 18, 21 etc.) deletions or translocations (Turner/Williams Syndrome, DiGeorge, to name a few). 3. Major organ system abnormalities not related to a genetic syndrome that are lethal or have extremely low probability for survival (i.e, bilateral kidney intrinsic disease, pulmonary hypoplasia, CNS (central nervous system) malformations: Arnold Chiari, myelomengoceles, hydranencephaly, squizencephaly, holoprocencephaly). 5. Any comorbidity or significant clinical event prior to enrollment, deemed by the Investigator as likely to affect survival or intestinal health. 6. Legally Authorized Representative(s) unwilling to comply with an exclusive human milk diet either in the form of mother's milk, human milk-based human milk fortifier, human milk based caloric fortifier or donor human milk during the initial hospitalization period and through the 28 day feeding period or hospital discharge, whichever comes first.