Comparison of singleton and multiple-birth outcomes of infants born at or before 32 weeks of gestation.

OBJECTIVE: To compare the outcomes of multiple-birth and singleton very preterm infants who were admitted to neonatal intensive care units (NICUs).

METHODS: Three-level hierarchical generalized linear and hierarchical linear model analyses were used to compare the risk-adjusted outcomes of 3,242 infants born at or before 32 weeks of gestational age who were admitted to 24 Canadian NICUs in 2005.

RESULTS: With the exception of respiratory distress syndrome (RDS), multiple-birth infants were not at a higher risk than singleton birth infants for death, patent ductus arteriosus, necrotizing enterocolitis, chronic lung disease, severe intraventricular hemorrhage, severe (stages 3 or higher) retinopathy of prematurity, or nosocomial infection, after adjusting for perinatal risks and neonatal illness severity. In addition, multiple-birth infants did not have a more prolonged duration of neonatal intensive care unit stay, duration of length of continuous positive airway pressure use, duration of ventilation, or duration of oxygen use than did singletons. Multiple-birth infants had a higher incidence of RDS (adjusted odds ratio 1.3, 95% confidence interval 1.0-1.6) and a lower incidence of severe retinopathy of prematurity (adjusted odds ratio 0.5, 95% confidence interval 0.3-0.9) than did singletons.

CONCLUSION: Multiple-birth and singleton very preterm infants had similar outcomes, except for a higher incidence of RDS among multiple-birth infants.

LEVEL OF EVIDENCE: II.