Monitoring FHR Using DECG
This chapter describes how to monitor a single fetal heart rate via direct ECG (DECG), using a spiral
fetal scalp electrode in the intrapartum period.
Read and adhere to the instructions that accompany the fetal scalp electrode, the DECG
adapter cable, and the attachment electrode. Pay attention to all the contraindications,
warnings, and for the DECG adapter cable, the cleaning and disinfection procedures.
Before starting to monitor, first define the fetal position, and ensure that it is suitable for DECG
Misidentification of MHR as FHR
Confirm fetal life before monitoring, and continue to confirm that the fetus is the signal source for the
FHR during monitoring. Here are two examples where the MHR can be misidentified as the FHR
when using a fetal scalp electrode:
Electrical impulses from the maternal heart can sometimes be transmitted to the fetal monitor
through a recently deceased fetus via the spiral scalp electrode, appearing to be a fetal signal
The recorded MHR, and any artifact, can be misinterpreted as a FHR especially when it is over
To reduce the possibility of mistaking the MHR for FHR, monitor both maternal and fetal heart rates
(see "Monitoring Maternal Heart / Pulse Rate" on page 213). The monitor's cross-channel verification
(CCV) facility can help by automatically detecting when the same heart rate is being recorded by
different transducers. See "Confirm Fetal Life Before Using the Monitor" on page 10 and "Cross-
Channel Verification (CCV)" on page 135.
Confirm that the scalp electrode is placed correctly.
Confirm fetal life by palpation of fetal movement or auscultation of fetal heart sounds using a
fetoscope, stethoscope, or Pinard stethoscope.
If you cannot hear the fetal heart sounds, and you cannot confirm fetal movement by palpation,
confirm fetal life using obstetric ultrasonography.
In case of difficulties deriving a stable maternal pulse reading using the Toco MP or CL Toco
transducer, use SpO
use MECG instead. Reasons to switch the method for deriving a maternal pulse or heart rate
INOP is issued at the fetal monitor if you are measuring FHR with DECG:
instead. In case of similar problems with the pulse measurement from SpO