How to Assess Heart Rate in a Neonate
Auscultation of the precordium with a stethoscope is the most accurate and reliable method for assessing heart rate in neonates and should be your primary approach. 1
Primary Method: Precordial Auscultation
Place the stethoscope directly over the precordium (chest wall) to listen to the heart - this remains the gold standard for heart rate assessment during neonatal resuscitation and routine examination. 1
Auscultation provides the most sensitive indicator of resuscitation efficacy when heart rate changes are needed to guide interventions. 1
Count for a full 30 seconds when the infant is in a quiet resting state (either asleep or awake but calm) for the most accurate assessment. 2
Alternative Method: Umbilical Pulse Palpation
If a stethoscope is unavailable, palpate the umbilical cord pulse - but be aware this method significantly underestimates heart rate. 1, 3
The umbilical pulse is more reliable than brachial or femoral pulse palpation in newborns. 4
In healthy term newborns, umbilical cord palpation correctly identified heart rate >100 bpm in only 55% of cases, with 20% showing undetectable pulses despite normal heart rates on auscultation. 4
Critical limitation: There is a high likelihood of underestimating heart rate with umbilical pulse palpation, though it remains preferable to other peripheral palpation sites. 1
Methods to Avoid
Do not rely on brachial pulse palpation - it correctly identified heart rate in only 25% of healthy newborns, with 60% showing undetectable pulses. 4
Do not use femoral pulse palpation - it was even less reliable, identifying correct heart rate in only 20% of cases with 45% undetectable. 4
Avoid carotid pulse palpation - studies show it requires significantly longer time (9.9 seconds) compared to other methods and has poor accuracy in infants. 5
Adjunctive Technology: Pulse Oximetry
For neonates requiring ongoing resuscitation or respiratory support, use pulse oximetry in conjunction with clinical assessment - not as a replacement. 1
Apply the sensor to the right hand or wrist BEFORE connecting the probe to the instrument - this produces reliable results more quickly. 1
Pulse oximetry typically requires 90 seconds from birth to obtain reliable heart rate measurements. 1
The oximeter probe should be placed on preductal sites (right wrist or hand) as these values are higher than postductal measurements. 1
Critical Action Thresholds
Heart rate <60 bpm with signs of poor perfusion requires immediate chest compressions - this indicates imminent cardiac arrest. 6, 7
A prompt increase in heart rate is the most sensitive indicator that your resuscitation efforts are effective. 1
Common Pitfalls to Avoid
Do not mistake absent peripheral pulses for absent cardiac activity - healthy newborns frequently have undetectable brachial and femoral pulses despite normal heart rates on auscultation. 4
Do not rely on color as an indicator - oxygenation and color improvement may take many minutes even in uncompromised babies. 1
Transient bradycardia during feeding, sleep, or defecation represents normal vagal tone and should not be misinterpreted as pathological. 6
Movement artifacts are common in neonatal monitoring and can lead to inaccurate readings, particularly with hiccoughs or electrical interference. 6