Fetal Heart Rate Signal Ambiguity

During labor and delivery, the fetal heart rate may be monitored through the use of an external monitor, known as a transducer, that is held to the maternal abdomen with an elastic strap.  The transducer is to be placed in a location where the device records the fetal heart rate which, in turn, is "traced" on paper or displayed on a computer screen for obstetric personnel to review when assessing fetal well-being.

If the transducer is not properly placed, fetal hart rate surveillance may be compromised by "signal ambiguity."  Signal ambiguity occurs when providers believe that the transducer is monitoring the fetal heart rate but it is actually monitoring the maternal heart rate.  While the maternal heart rate is being monitored, the fetal heart rate is not being monitored and, if there is fetal distress due to hypoxia, the warning signs will not be visible and the fetus may sustain permanent injury.

A failure to properly monitor the fetal heart rate may  be medical negligence.  Experienced obstetrical providers know that there are ways to distinguish between the fetal heart rate and maternal heart rate.  Distinguishing characteristics include:
  • maternal heart rate typically is slower than fetal heart rate;
  • maternal heart rate accelerates during contractions;
  • maternal heart rate does not decelerate;
  • fetal heart rate decelerates during contractions; and
  • fetal heart rate rarely has repeated accelerations.
Maternal pulse oximetry, especially in second stage, is a tool available to help eliminate the risk of confusion caused by signal ambiguity, but it is not foolproof as the pulse rate printout from the pulse oximeter is affected by maternal movement and other factors.

Finally, placement of a fetal scalp electrode eliminates the possibility of any confusion when conducting fetal heart rate surveillance, as the electrode is manually attached to the fetal scalp and cannot record maternal tones.

The trial lawyers at Bottar Leone, PLLC, have decades of experience investigating, prosecuting and trying to verdict medical malpractice and birth injury cases.  If you or your baby have been injured due to medical malpractice, you, your child and your family may be entitled to compensation for lifelong health care, medical expenses, special education, medical bills, loss of income, and pain and suffering. 

To discuss your case or concerns with an experienced Central New York medical malpractice and birth injury attorney, contact us now at (315) 422-3466, (800) 336-LAWS, or by e-mail at info@bottarleone.com.