Significant advances in perinatology and neonatology in recent decades have resulted in higher survival rates for extremely premature infants, i.e., those born at a gestational age of less than 26 weeks or weighing 750 grams or less at birth. Studies published during the last 5 years report survival rates ranging from 33% to 62% for extremely premature infants. The variance in the reported prevalence of major complications of prematurity among the hsurvivors is also considerable. Bronchopulmonary dysplasia is the most prevalent complication (35–80% of surviving infants born before reaching a gestational age of 26 weeks are affected), followed by severe intraventricular hemorrhage and retinopathy of prematurity (17–36% and 9–18% of surviving infants born at 26 weeks of gestation or earlier, respectively, are affected). These differences in survival and complication rates depend among other things on the study design and on the policy for initiation of neonatal intensive care. Mortality and major neonatal morbidity in survivors are consistently shown to decrease with increasing gestational age and birth weight.