Abstract
The neonatal intensive care unit (NICU) is a specialized unit that provides neonates with appropriate medical care. The length of stay (LOS) in the NICU is a crucial index for determining the efficiency of the quality of care provided to neonates. Longer stay is associated with several consequences, including mortality. Longer stays and neonatal mortality in NICU can be reduced by the identification of risk factors to provide timely treatment. This review was conducted to assess determinants of LOS and mortality in NICU by reviewing the previous research that investigated such factors. Scientific terms were used to search through scientific databases for related studies. Eligible studies were original English studies that reported risk factors of LOS and/or mortality in NICU with the availability of full-text and full data. Eleven studies with 28,327 neonates were included; the findings included the risk factors of LOS, rates of mortality, and risk factors. The major determinants of NICU LOS included low birth weight, low gestational age, and several neonatal complications. The mortality rates in NICU were high and the major risk factors of neonatal mortality in NICU, included infection, asphyxia, sepsis, low birth weight, obstetric and maternal complications, and neonatal complications.

Key words: NICU, mortality, LOS, determinants, risk factors