Admission test as predictor of intrauterine fetal asphyxia.

This study determined the accuracy of the admission test in predicting intrauterine fetal asphyxia. A total of 229 subjects were included. The admission test, a short continuous electronic fetal monitoring recording, was made immediately on admission, on all patients in labor, and was categorized as "reassuring", "equivocal", or "ominous". Intrauterine fetal asphyxia was considered to be present when the umbilical cord blood pH was 7.2 and/or the Apgar score was 7 at 1 minute; an "ominous" admission test has a high accuracy (LR = 8.54) in predicting intrauterine fetal asphyxia, while a "reassuring" admission test does not rule out the possibility of asphyxia (LR = 0.39). "Reassuring" tracing is associated with low risk (6.5%) for asphyxia as measured by Apgar score and umbilical cord pH, while "ominous" tracing is associated with high risk (50%) for asphyxia. In detecting an umbilical cord pH of 7.2, fetal heart rate variability is the most specific (98%), while absence of acceleration is the most sensitive (50%).