FHR Basics
What is the normal baseline fetal heart rate range?
110–160 bpm
Which device externally measures uterine contractions?
Tocotransducer
What does variability in FHR reflect?
Intact and oxygenated autonomic nervous system
What are accelerations and why are they important?
Abrupt, transient FHR increases; most reassuring sign of fetal well-being
What FHR category is reassuring?
Category I (normal baseline, moderate variability, accelerations present/absent, no late/variable decels)
Define tachycardia in the fetus.
Baseline FHR >160 bpm lasting at least 10 minutes
What is the only method that can quantify contraction pressure in mmHg?
Intrauterine Pressure Catheter (IUPC)
Amplitude range undetectable = what type of variability?
Absent variability
Criteria for accelerations at ≥32 weeks?
≥15 bpm above baseline for ≥15 seconds
What FHR category requires intrauterine resuscitation and expedited birth?
Category III
Define bradycardia in the fetus.
Baseline FHR <110 bpm lasting more than 10 minutes
Normal contraction peak intensity measured internally is approximately?
70–90 mmHg
Amplitude <5 bpm = what variability level?
Minimal variability
What causes early decelerations and are they concerning?
Fetal head compression; benign, no intervention needed
Give two intrauterine resuscitation measures for non-reassuring patterns.
Reposition mother, administer oxygen, IV fluids, stop oxytocin, notify provider
Name one advantage and one disadvantage of internal fetal monitoring (FSE/ISE).
Advantage: Most accurate, no artifact. Disadvantage: Requires ROM, cannot place on face/fontanel/genitals
Describe how mild, moderate, and strong contractions feel on palpation.
Mild = tip of nose, Moderate = chin, Strong = forehead
Amplitude 6–25 bpm = what variability level?
Moderate variability
What is the usual cause of variable decelerations?
Umbilical cord compression
Describe a prolonged deceleration.
FHR decrease >15 bpm lasting 2–10 minutes
What are the goals of FHR monitoring?
Assess fetal well-being, maternal well-being, labor progress, and effects of interventions
Define contraction frequency and duration.
Frequency = start of one contraction to start of next (minutes);
Duration = beginning to end of one contraction (seconds)
Amplitude >25 bpm = what variability level?
Marked variability
What causes late decelerations and why are they concerning?
Uteroplacental insufficiency → indicates oxygenation problem
What pattern is very abnormal, associated with severe hypoxia/anemia, and appears wave-like?
Sinusoidal pattern