COMPARISON OF INTRAPARTUM ELECTRONIC FETAL HEART-RATE MONITORING VERSUS INTERMITTENT AUSCULTATION IN DETECTING FETAL ACIDEMIA AT BIRTH

OBJECTIVE: Our purpose was to compare continuous intrapartum electroni c fetal heart rate monitoring with intermittent auscultation for detec ting fetal acidemia at birth. STUDY DESIGN: Data from a previously pub lished randomized trial of electronic fetal heart rate monitoring vers us intermittent auscultation were analyzed to identify any differences between the two methods in detecting fetal acidemia at birth. Fetal a cidemia at birth was defined as the presence of cord blood arterial pH < 7.15. RESULTS: A total of 1419 patients with umbilical cord blood a cid-base measurements were identified, 739 in the electronic FHR monit oring group and 680 in the auscultation group. Electronic FHR monitori ng had significantly better sensitivity (97% vs 34%, p < 0.001), lower specificity (84% vs 91%, p < 0.001), higher positive predictive value (37% vs 22%, p < 0.05), and higher negative predictive value (99.5% v s 95%, p < 0.001) in detecting fetal acidemia at birth. in addition, e lectronic FHR monitoring was significantly better in detecting all typ es of acidemia: metabolic (95.5% vs 26.5%, p < 0.001), mixed (95% vs 3 7.5%, p < 0.001), and respiratory (100% vs 41.5%, p < 0.001). CONCLUSI ON: These data suggest that electronic FHR monitoring is superior to i ntermittent auscultation in detecting fetal acidemia at birth.