Physicians' subjectivity in evaluating oxytocin challenge tests

Five physicians subspecializing in maternal-fetal medicine individually evaluated 50 oxytocin challenge tests (OCTs), of which 33 were originally read as positive. There was considerable disagreement among the study physicians (SPs) such that 2 SPs would agree, on the average, only 52% of the time on any one OCT. The SPs were also asked to evaluate fetal heart rate (FHR) reactivity patterns, if present. Again, there was great disagreement. When the majority (3 of 5 or more) of SPs agreed on the OCT result and/or reactivity, there was reasonable correlation with neonatal outcome, indicating the validity of the physiologic premise of the test. In particular, the presence or absence of FHR accelerations with fetal motion, regardless of the OCT reading, correlated extremely well with eventual neonatal outcome. This indicates that the most significant variable in antepartum FHR monitoring is the FHR acceleration pattern.