656 657 ANTENATAL SONOGRAPHIC PREDICTORS OF NEONATAL SURVIVAL IN EXTREME PREMATURITY JOYCE D. RUBIN, REINALDO FIGUEROA, ANDREW ELIMIAN, PAUL OGBURN JR, J. GERALD QUIRK, DAVID GARRY, State University of New York at Stony Brook, Obstetrics, Gynecology and Reproductive Medicine, Stony Brook, NY OBJECTIVE: The purpose of this study was to determine whether antenatal sonographic biometric measurement(s) could predict survival in extremely premature neonates. STUDY DESIGN: The study population included all live-born babies with a GA 22-25 wk, delivered at our hospital from 1995-2002, and who had prenatal ultrasound < 10 days prior to delivery. GA was based on LMP or sonographic estimates obtained < 14 wk. The maternal charts were reviewed for basic demographic characteristics, which included age, parity, and ethnicity. Sonographic biometric measurements included the BPD, HC, FL, AC, and EFW. The EFW was calculated with the formula of Hadlock et al. Excluded from the study were cases missing any of the biometric data, stillborns, and those cases with a chromosomal or structural anomaly. Neonatal information obtained from the chart included BW, Apgar score, and survival. Survival was defined as discharge of a live infant from the hospital. The study was IRB-approved and statistical analysis considered a P value of < .05 as significant. RESULTS: There were 120 newborns meeting entry criteria with an overall survival of 50%. Neonatal survival rates at 22, 23, 24, and 25 wk were 8%, 23%, 56%, and 69%, respectively. The threshold values for each biometric measurement below which there was no survival were BPD < 4.8 cm, HC < 18.0 cm, AC <16.4 cm, FL < 3.8 cm, and EFW <450 g. The most significant independent sonographic predictors of neonatal survival were the HC (P = .04) and FL (P = .01). The EFW, BPD, and AC were not predictors of survival. The mean difference of EFW from actual BW was -33.7 ± 146 g or a 2.4%. CONCLUSION: Sonographic measurement of the HC or FL can predict Volume 189, Number 6 Am J Obstet Gynecol SMFM Abstracts S237