OBJECTIVE: This study compares the neonatal morbidity and mortality of the smallest twins of monochorionic diamniotic (MCDA) pregnancies complicated with selective intrauterine growth restriction (sIUGR) with newborns from singleton pregnancies with intrauterine growth restriction (IUGR). METHODS: We conducted a retrospective cohort study of patients managed at the prenatal diagnosis center in a single tertiary care hospital between 2012 and 2019. MCDA twin pregnancies complicated with sIUGR (sIUGR group) were compared with singleton pregnancies with IUGR (IUGR group). The primary outcome was the comparison in neonatal morbidity and mortality between the two groups. RESULTS: The analysis included 251 patients: 67 in the sIUGR group and 184 in the IUGR group. The two groups were comparable in gestational age and birth weight (p \textgreater 0.05). Multivariate analysis controlling for factors that may influence neonatal status showed no significant difference between the two groups in any of the neonatal morbidity criteria or the composite morbidity-mortality endpoint (adjusted OR = 0.946 [95% CI = 0.317-2.827]; p = 0.921). CONCLUSION: Despite supposedly different pathophysiological mechanisms, neonates from MCDA pregnancies complicated with sIUGR and those from singleton pregnancies with IUGR appear to have identical neonatal morbidity and mortality .