PERINATAL FACTORS INFLUENCING SURVIVAL AT 24 WEEKS GESTATION

OBJECTIVE: Our objective was to identify those obstetric and neonatal factors associated with survival in infants delivered at 24 weeks' ges tation. STUDY DESIGN: The obstetric and pediatric data bases from the two hospitals in our perinatal center were examined to ascertain all i nfants delivered between 1987 and 1989 whose gestational age was 24 we eks to 24 weeks 6 days. This time interval was chosen to coincide with the introduction of prophylactic exogenous surfactant. Data were abst racted from the maternal antepartum and intrapartum records and the ne onatal records, with specific attention to objective risk factors rela ted to survival. RESULTS: Forty-five pregnant patients were identified and delivered of 52 infants. Seventeen newborn infants survived (33%) . Univariate comparisons between survivors and nonsurvivors revealed m ore aggressive intrapartum care in the former cohort as represented by the frequencies of internal fetal heart rate monitoring (p = 0.005), maternal oxygen therapy (p = 0.003), and maternal position change to r emediate decelerations (p = 0.001). Planned exclusion of cesarean deli very was more common in those pregnancies that ended in fetal or neona tal death (29/35 vs 7/17; p = 0.006). Although a greater proportion of infants delivered by cesarean section survived (6/11 vs 11/41), this difference was not significant (p = 0.17). With the use of logistic re gression, the best predictor of survival was gestational age at delive ry. Neonatal care was more aggressive among survivors, as measured by the relative frequencies of resuscitation and surfactant administratio n. Respiratory distress syndrome was either absent (n = 6) or mild (n = 6) in a majority of the survivors, and respiratory insufficiency was the major cause of neonatal death. CONCLUSION: Perinatal outcome at 2 4 weeks' gestation appears most dependent on gestational age at delive ry. The intensity of intrapartum care and neonatal support, as well as clinical biases regarding survivability, may also influence outcome.