The use of fetal monitors to monitor fetal rate began at Yale University in 1958. Today, most hospitals use fetal monitoring as a standard component of the labor and delivery process. Fetal monitoring can provide valuable information, such as detecting dips in your baby’s heart rate due to lack of oxygen. However, if the person assigned to read fetal monitor strips does so incorrectly this process can involve risks, such as incorrectly diagnosing an emergency condition, according to a report published in the American Family Physician.
Examine the graph-style layout of the fetal monitor strip and identify its three main parts. The top part of the strip is where the fetal heart rate displays as beats per minute. The middle section displays time in increments of 10 seconds per square on the chart, totaling six squares per minute. The bottom section displays the intensity and length of uterine contractions as a series of bell curves that start. To help you become familiar with the layout of a fetal monitor strip, look at the samples provided at FetalMonitorStrips.com.
Identify the baseline heart rate. Locate the number of beats per minute on the top section of the fetal monitor strip. A range of 120 to 160 beats per minute indicates a normal fetal heart rate but a deviation, or change, of 10 beats or less in your baby’s heart rate is normal. However, any change greater than 10 beats per minute that lasts longer than 15 minutes corresponds to a change in the base line heart rate.
Examine the bottom section of the fetal monitor strip and identify a range of zero to 10 on the strip. This is a reference point that represents your uterus in a relaxed state. The trace line will follow your contractions as they build, crest and then return to the reference point.
Compare changes in the fetal heart rate as they correspond to the intensity and duration of your contractions and look for patterns. Fetal heart rate patterns include reassuring, nonreassuring or ominous. A reassuring pattern displays during a contraction as an upward deviation from the baseline that returns to normal within 15 seconds. A nonreassuring deviation is, for example, a pattern that displays during a contraction as a slight downward deviation that returns to normal but may indicate compression of the umbilical cord and require a shift in your position. An ominous deviation dips below the baseline and recovers either slowly or not at all, indicating fetal stress due to oxygen deprivation that requires immediate medical intervention.
There are two ways your doctor can conduct fetal monitoring. The first, and most common, is external fetal monitoring that involves strapping external transducers to your abdomen. External transducers detect your baby’s heart rate via Doppler ultrasound, then transmit and display this information on a fetal monitor strip. The second method is internal fetal monitoring that involves placing electrodes on your baby’s scalp. The electrodes detect, transmit and display heart rate information on the fetal monitor strip.