Maternal or Fetal Heart Rate? Avoiding Intrapartum Misidentification Michelle L. Murray, PhD, RNC, CNS  Journal of Obstetric, Gynecologic & Neonatal Nursing  Volume 33, Issue 1, Pages 93-104 (January 2004) DOI: 10.1177/0884217503261161 Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 1 Tracing of MHR near 87 bpm and doubling of the MHR near 174 bpm, which was erroneously interpreted as the FHR. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 2 Spiral electrode tracing of a flat MHR baseline at 140 bpm with artifact, in a patient with preeclampsia, diabetes, and severe hypoglycemia (22 mg/dl). The baby was stillborn. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 3 Second-stage MHR of 90–95 bpm with accelerations, and FHR of 150 bpm with tachycardia, absent short-term variability, and variable decelerations. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 4 Maternal decelerations. Top tracing is the FHR between 130 and 140 bpm. Bottom tracing reflects a maternal baseline near 95 to 108 bpm with decelerations that mimic fetal variable decelerations. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 5 Tracing from patient attempting trial of labor after cesarean, when pushing began, approximately 30 minutes after a complaint of sharp abdominal pain. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 6 Tracing from TOLAC patient after 2 Vi hours of pushing, in which maternal heart rate rather than FHR was now being recorded. Note maternal uniform accelerations with each contraction. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 7 Terminal fetal bradycardia in a patient with chorioamnionitis. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 8 Maternal tachycardia mistaken for FHR in patient with chorioamnionitis, 30 minutes after fetal bradycardia was noted and intrauterine resuscitation was attempted using terbutaline and knee-chest position. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 9 Tracing from patient at 25 weeks gestation with past history of substance abuse, with a closed cervix, when she began thrashing and asking for pain medication. The recording is of the MHR with occasional doubling. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 10 FHR tracing from patient at 25 weeks gestation with abdominal pain and history of substance use, showing brief variable decelerations typical of FHR rather than MHR, and continued uterine hyperactivity after one dose of terbutaline. MHR at this time was 86 bpm. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions

FIGURE 11 Tracing from patient at 25 weeks gestation with history of substance abuse and abdominal pain, after second dose of terbutaline. In retrospect, this tracing was probably the MHR. Journal of Obstetric, Gynecologic & Neonatal Nursing 2004 33, 93-104DOI: (10.1177/0884217503261161) Copyright © 2004 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses Terms and Conditions