Objectives: To assess risk factors and develop a simple estimate method for poor neonatal outcomes for specific groups of extremely premature infants at birth.
Design: Population-based study.
Setting: Israel National Very Low Birth Weight Infant Database.
Participants: Infants born at 23 to 26 weeks' gestation between January 1, 1995, and December 31, 2008.
Intervention: We developed a tool to estimate poor neonatal outcomes for infants born at 24 to 26 weeks' gestation (n=2544) that incorporated factors at birth significantly associated with poor outcomes into a linear regression model.
Main outcome measures: Poor neonatal outcomes defined as the composite of mortality or severe neurologic or pulmonary morbidity at discharge from the hospital.
Results: Major factors associated with poor outcomes at 24 to 26 weeks' gestation were gestational age, male sex, sex-specific birth weight percentile, and lack of prenatal steroid therapy. Estimated poor outcomes for January 1, 2000, to December 31, 2008, were calculated as the sum of the percentages determined for each of the 4 parameters: (1) gestational age (26, 25, and 24 weeks; 0%, 17%, and 34%, respectively), (2) birth weight percentile (>75th, 25th-75th, and < 25th percentiles; 0%,13%, and 26%, respectively), (3) lack of prenatal steroids (16%), and (4) male sex (7%). There was also an intercept value of 25%. Estimated poor outcome rates for the 36 subgroups of infants ranged from 25% to 100%and correlated well with observed rates (intraclass correlation coefficient, 0.93).
Conclusions: The combined outcomes of deaths or severe morbidities in the neonatal period of infants born at 24 to 26 weeks' gestation could be simply estimated at birth. The provision of an appropriate and up-to-date estimate of poor neonatal outcomes for specific infants may be useful in counseling families on treatment options for these infants.