Abstract
Objective Advances in neonatology have made possible the survival of neonates with lower gestational
ages and birth weights. Nevertheless, findings remain of a sex difference in mortality
for premature and low birth weight (LBW) neonates with male sex often associated with
poorer outcome (the “male disadvantage”). Through literature review, this article
will seek clarification of the existing evidence regarding the association between
sex and mortality at discharge from neonatal intensive care units (NICUs) for premature
and LBW neonates.
Methods A systematic review was conducted in Medline and Google Scholar with subsequent search
of study reference lists.
Results The database search yielded 349 articles and an additional 11 were identified from
study reference lists. A final 32 studies were reviewed. Of these, 26 studies demonstrated
worse male mortality outcome and 6 studies reported no sex difference in mortality.
Conclusion The majority of reviewed studies found poorer male mortality outcome. A small number
of studies maintained a null association between sex and mortality. This indicates
male premature and LBW neonates experience higher risk of mortality by discharge compared
with females, an observation which may inform clinical decision making in the NICU.
Keywords
mortality - survival - sex difference - neonate - premature - low birth weight
