11 Monitoring FHR and FMP Using Ultrasound
Maternal-Switching (Maternal Insertion)
Noisy/Erratic Signal and Dropout
Selection of Literature References on Artifacts
Fetal Monitoring, A Multidisciplinary Approach, Seventh edition
Susan M. Tucker, Lisa A. Miller, David A. Miller
Mosby Inc. 2009, ISBN 978-0-323-08352-2
170 - Tachycardia
Unable to determine
Maternal insertion, noise
The fetus has an elevated baseline rate of about 170 bpm with minimal to moderate
variability. The ability to assess fetal status is limited because about half of the tracing
displays the maternal heart rate.
The application of a maternal transducer (ECG or pulse oximeter) will likely resolve any
possible confusion with the tracing. Repositioning the transducer may produce a more
reliable tracing. Consideration must also be given to applying a fetal scalp electrode.
Noisy signal, drop-out
Reassuring tracing. Note that there is episodic drop out of the signal with discontinuity of the
Either improving the position of the transducer or the application of a fetal scalp electrode
will reduce the amount of artifact in the tracing.