Comparing the Fetal ST Segment Acquired Using a
Fetal Scalp Electrode and Abdominal Electrodes

Objective:

To compare fetal ST-segment deviation measured using sensors on the maternal abdomen to the fetal ST-segment deviation acquired using a fetal scalp electrode (FSE).

Methods:

Data were acquired from 27 term
laboring women who had a FSE placed for a clinical indication. 29 channels of abdominal data and one precordial channel were recorded simultaneously with the FSE. The data were preprocessed for removal of interference from maternal ECG as well as power‐line contamination and other sources of background noise, such as muscle artifact.

The median ST level was estimated from 79 10-second segments fro the FSE and abdominal data.

Methods (cont'd):

The statistical comparison was performed to access the accuracy of the ST-segment deviation (elevation or depression) derived from the abdominal sensors compared to the FSE.

IRB approved and informed consent were obtained.

Results:

ST elevation from the isoelectric point ranged from 0-2% of R-wave amplitude. ST depression ranged from 0-1.5% of R-wave amplitude. The route mean square error between the ST deviation calculated by both methods averaged over all processed segments was 0.52%, and the mean absolute difference was 0.29%.

Conclusion:

ST deviation calculated from
ECG acquired from the
maternal abdomen is clinically indistinguishable from ST-segment deviation measured using the fetal scalp electrode (FSE).

Disclosure: The authors, except for Ms. Pettigrew, hold equity in MindChild Medical, Inc., which has licensed intellectual property used to generate results presented in this abstract.