A fetal monitor is a device used to monitor the(FHR) and uterine contractions during labor. The FHR is measured in beats per minute (bpm), and the uterine contractions are measured in millimeters of mercury (mmHg). Contractions are recorded on the fetal monitor as a waveform, which can be used to determine the strength, duration, and frequency of the contractions.
To read contractions on a fetal monitor, first identify the baseline FHR. The baseline FHR is the average FHR over a 10-minute period. Contractions are then identified as deviations from the baseline FHR. A contraction begins when the FHR decreases below the baseline FHR, and ends when the FHR returns to the baseline FHR. The strength of a contraction is measured by the amplitude of the waveform, which is the difference between the peak and trough of the waveform. The duration of a contraction is measured from the beginning to the end of the waveform. The frequency of contractions is measured by the number of contractions in a 10-minute period.
