Predictive factors for survival for out-born infants born between 23 and 24 weeks of gestation in the post-surfactant era: fourteen years' experience in a single neonatal care unit, 1987-2000.

Background: The purpose of the present paper was to identify the predictive factors for survival for out-born infants born between 23 and 24 weeks of gestation.

Methods: Ninety-two infants born between 23 and 24 weeks' gestation who were admitted to a level III neonatal intensive care unit from 1987 to 2000, were retrospectively studied. Survival was defined as discharge from the neonatal intensive care unit. Logistic regression was done to determine which clinical factors were most predictive of survival. The independent variables that were entered into the models were determined by preliminary univariate analysis.

Results: Ninety-two infants were enrolled in the present study, 49 of whom survived in the surfactant era. The four variables that were found to be most predictive for survival on logistic regression were systolic blood pressure at 6 h (odds ratio [OR], 1.3; 95% confidence interval [CI]: 1.11-1.44 1 mmHg), ventilatory index < 0.047 (OR, 4.8; 95%CI: 1.07-21.65), initial hemoglobin value (OR, 1.6; 95%CI: 1.09-2.34/1 g/dL), and base excess at 6 h (OR, 2.1; 95%CI: 1.08-1.84/5 mEq/L).

Conclusions: A total of 53.2% of infants delivered between 23 and 24 weeks of gestation survived at discharge after introduction of surfactant replacement therapy. Early cardiopulmonary adaptation and initial hemoglobin value are key factors for survival in infants born at 23-24 weeks of gestation.