Outcomes and Milestone Achievement Differences for Very Low-birth-weight Multiples Compared with Singleton Infants

We examined if very low-birth-weight (VLBW) infants of multiple gestation pregnancies experience more complications and take longer to achieve clinical milestones compared with similar singletons. We performed a retrospective analysis of all infants less than 1500 g at birth in a large neonatal database. Singletons were compared with twins and higher-order multiples for demographic, morbidities, and process milestones including feeding, respiratory, thermoregulation, and length of stay. Multivariable regression analyses were performed to control for potential confounding variables. A total of 5507 infants were included: 3792 singletons, 1391 twins, and 324 higher-order multiples. There were no differences in Apgar scores, small for gestational age status, and incidence of necrotizing enterocolitis, severe retinopathy of prematurity, severe intraventricular hemorrhage, sepsis, bronchopulmonary dysplasia, or the need for surgery. Multiples had higher rates of apnea and patent ductus arteriosus than singletons. VLBW multiples achieved milestones at similar rates in most areas compared with singletons except for the achievement of full oral feedings. Length of stay, after controlling for confounding variables, did not differ between the groups. Compared with singletons, VLBW multiples had similar morbidity and achieved most feeding and thermoregulation milestones at similar rates.