NeoReviews Vol.7 No.5 2006 e272
© 2006 American Academy of Pediatrics
Strip of the Month
May 2006
Maurice L. Druzin, MD*
Julie M.R. Arafeh, RN, MSN
* Charles B. and Ann L. Johnson Professor of Obstetrics; Chief, Division of Materna-Fetal Medicine; Co-Medical Director, Mid-Coastal California Perinatal Outreach Program, Stanford University School of Medicine, Palo Alto, Calif
Coordinator of Perinatal Outreach, Mid-Coastal California Perinatal Outreach Program, Stanford University, Palo Alto, Calif
| The first 300 words of the full text of this article appear below. |
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Electronic Fetal Monitoring Case Review Series
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Electronic fetal monitoring (EFM) is a popular technology used to establish fetal well-being. Despite its widespread use, terminology used to describe patterns seen on the monitor has not been consistent until recently. In 1997, the National Institute of Child Health and Human Development (NICHD) Research Planning Workshop published guidelines for interpretation of fetal tracings. This publication was the culmination of 2 years of work by a panel of experts in the field of fetal monitoring and has been endorsed by both the American College of Obstetricians and Gynecologists (ACOG) and the Association of Womens Health, Obstetric and Neonatal Nurses (AWHONN). The terminology definitions and assumptions found in the NICHD publication form the basis for interpretation of the fetal tracings in this series and are summarized here. Normal values for arterial umbilical cord gas values and indications of acidosis are defined in Table 1.
Table 1. Arterial Umbilical Cord Gas Values
|
pH |
PCO2 (mm Hg) |
PO2 (mm Hg) |
Base Excess |
|
| Normal* |
7.20 |
<60 |
20 |
10 |
|
(7.15 to 7.38) |
(35 to 70) |
|
(2.0 to 9.0) |
| Respiratory Acidosis |
<7.20 |
>60 |
Variable |
10 |
| Metabolic Acidosis |
<7.20 |
<60 |
Variable |
10 |
| Mixed Acidosis |
<7.20 |
>60 |
Variable |
10 |
|
* Normal ranges from Obstet Gynecol Clin North Am. 1999;26:695
Assumptions from the NICHD Workshop
- Definitions are developed for visual interpretation
- Definitions apply to tracings generated by internal or external monitoring devices
- Periodic patterns are differentiated based on waveform, abrupt or gradual (eg, late decelerations have a gradual onset and variable decelerations have an abrupt onset)
- Long- and short-term variability are evaluated visually as a unit
- Gestational age of the fetus is considered when evaluating patterns
- Components of fetal heart rate (FHR) do not occur alone and generally evolve over time
Definitions
Baseline Fetal Heart Rate
- Approximate mean FHR rounded to increments of 5 beats/min in a 10-minute segment of tracing, excluding periodic or episodic changes, periods of marked variability, and segments of baseline that differ by >25 beats/min
- In the 10-minute segment, the minimum baseline duration must be at least 2 minutes or the baseline for that segment is indeterminate
- Bradycardia is a baseline of <110 beats/min; tachycardia is a . . . [Full Text of this Article]
Copyright © 2006 by the American Academy of Pediatrics.