Advertisement

Did the maternal pulse mask the fetal heart rate of acidemic infants with no explanatory features?

Published:April 26, 2018DOI:https://doi.org/10.1016/j.ajog.2018.04.036
      To the Editors:
      I read the study by Clark et al
      • Clark S.L.
      • Hamilton E.F.
      • Garite T.J.
      • Timmins A.
      • Warrick P.A.
      • Smith S.
      The limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia.
      that evaluated an algorithm to manage category II fetal tracings with great interest and admiration. Regarding the 18% of infants with acidemia with no explanatory features on review of the fetal heart rate tracing, is it possible that the maternal pulse was mistaken for the fetal heart rate (also known as signal ambiguity)?
      • Neilson D.R.
      • Freeman R.K.
      • Mangan S.
      Signal ambiguity resulting in unexpected outcome with external fetal heart rate monitoring.
      • Freeman R.K.
      • Garite T.J.
      • Nageotte M.P.
      • Miller L.A.
      Fetal heart rate monitoring.
      Certain fetal monitors are reported to be more susceptible to subtle transitions from the fetal heart rate to the maternal pulse and, as has been described, monitoring the maternal pulse may look similar to a category I fetal heart rate tracing, especially in the active second stage.
      • Neilson D.R.
      • Freeman R.K.
      • Mangan S.
      Signal ambiguity resulting in unexpected outcome with external fetal heart rate monitoring.
      • Freeman R.K.
      • Garite T.J.
      • Nageotte M.P.
      • Miller L.A.
      Fetal heart rate monitoring.
      • Kiely D.J.
      The incidence of maternal artefact during intrapartum fetal heart rate monitoring.
      It may, thereby, also be of interest to know which fetal monitors were used in the study.

      References

        • Clark S.L.
        • Hamilton E.F.
        • Garite T.J.
        • Timmins A.
        • Warrick P.A.
        • Smith S.
        The limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia.
        Am J Obstet Gynecol. 2017; 216: 163.e1-163.e6
        • Neilson D.R.
        • Freeman R.K.
        • Mangan S.
        Signal ambiguity resulting in unexpected outcome with external fetal heart rate monitoring.
        Am J Obstet Gynecol. 2008; 198: 717-724
        • Freeman R.K.
        • Garite T.J.
        • Nageotte M.P.
        • Miller L.A.
        Fetal heart rate monitoring.
        4th ed. Lippincott Williams & Wilkins, Philadelphia2012: 59-61
        • Kiely D.J.
        The incidence of maternal artefact during intrapartum fetal heart rate monitoring.
        J Obstet Gynaecol Can. 2015; 37: 205-206

      Linked Article

      • The limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia
        American Journal of Obstetrics & GynecologyVol. 216Issue 2
        • Preview
          Despite intensive efforts directed at initial training in fetal heart rate interpretation, continuing medical education, board certification/recertification, team training, and the development of specific protocols for the management of abnormal fetal heart rate patterns, the goals of consistently preventing hypoxia-induced fetal metabolic acidemia and neurologic injury remain elusive.
        • Full-Text
        • PDF
      • Reply
        American Journal of Obstetrics & GynecologyVol. 219Issue 3
        • Preview
          We thank Dr Keily for his interest in our article. The heart rate tracings in question were not maternal, for the following reasons: (1) We are aware of that phenomenon and the characteristic signs such as broad “accelerations” coinciding with contractions. This was not observed in this series where we reviewed every case of failed identification by the algorithm. (2) Newer fetal heart rate sensors will search automatically for maternal fetal coincidence (same heart rates) and warn clinicians of its existence.
        • Full-Text
        • PDF