Diagnosis of an unsuspected maternal hemorrhage via fetal heart rate tracing

Early detection of placental abruption often relies on the observation of vaginal bleeding; however, overt bleeding does not always occur. We report the case of an unsuspected placental abruption diagnosis that was prompted by an internal fetal scalp electrode tracing. The presence of a "normal" fetal heart rate (FHR) of approximately 150 beats per minute with poor variability, which matched the maternal heart rate (MHR), suggested that the tracing was not of fetal origin. An urgent ultrasound examination revealed a fetal demise with a possible concealed abruption, proving that the scalp electrode tracing was actually maternal in origin. Though reports of transmission of MHR via a deceased fetus are not new, it is uncommon for MHR to mimic a normal, reassuring FHR. This report reinforces the need for anesthesiologists to be adept at interpreting and integrating FHR monitors with maternal monitors prior to initiation of epidural analgesia.