“…Perinatal outcomes included GA at birth, fetal gender, birth weight, presence or absence of growth restriction with birth weight <3%, presence or absence of respiratory distress syndrome (RDS), bronchopulmonary dysplasia, intraventricular hemorrhage (IVH), periventricular leukomalacia, necrotizing enterocolitis, retinopathy of prematurity (ROP), neonatal sepsis, perinatal death and neonatal stay in the Neonatal Intensive Care Unit (NICU) as defined by accepted international classifications. [19][20][21] Adverse neonatal outcomes were additionally combined in a moderate morbidity index defined as one or more of the following outcomes: RDS, IVH grades 1 or 2, ROP grades 1 or 2 or neonatal sepsis and a severe morbidity index defined as one or more of IVH grades 3 or 4, periventricular leukomalacia, necrotizing enterocolitis, ROP grades 3 or 4, bronchopulmonary dysplasia or perinatal death. These morbidity indices were designed to address the clinical impact of a neonatal outcome that either has a major effect on infant health (severe morbidity index), or a minor effect with less impact on long-term health (moderate morbidity index).…”