Male disadvantage for neonatal complications of term infants, especially in small-for-gestational age neonates.

Objective: Sex differences in long and short-term outcomes for infants are observed. This has also been shown for several neonatal complications in preterm neonates. We aimed to evaluate whether sex impacts neonatal outcome among term neonates. Furthermore, we were interested in whether small-for-gestational age male and female neonates at term presented with different patterns of neonatal complications.

Methods: Data on all term singleton deliveries and respective neonatal outcomes between 2004 and 2008 at a single tertiary medical center were utilized for this retrospective cohort study. Immediate neurological complications were defined as one or more of the following: intraventricular hemorrhage, convulsions, asphyxia and acidosis. Neonatal complications were compared between male and female term infants, as well as male and female term small-for-gestational age (SGA) neonates.

Results: 37,342 singleton neonates were born ≥37 weeks' gestation. 19,112 neonates were males. Birth weight, cesarean sections and operative deliveries were significantly higher for males. Neonatal hypoglycemia and immediate neurological complications were significantly more frequent in males. For term SGA's, low 5-min apgar scores (<7) at 39-40 weeks were 2.65 times higher for males compared with females, as was hypoglycemia.

Conclusions: Male infants at term, especially male SGA infants, are more likely to encounter complications during labor and require special neonatal care due to metabolic and/or neurological complications.