Determination of heart rate in the baby at birth

The International Liaison Committee on Resuscitation (ILCOR) publishes guidelines on neonatal resuscitation, which are evidence-based where possible. Initial assessment of heart rate, breathing and colour is an essential part of newborn resuscitation and the guidelines state that heart rate may be assessed using a stethoscope, or palpating the umbilical, brachial or femoral pulse. This study aimed to assess the most effective method(s) of heart rate assessment in the newborn baby. Healthy term newborn babies were randomised to femoral, brachial or cord pulse assessment, within 5min of birth. The heart rate (beats per minute (bpm)) was categorised as either not detectable, <60, 60-100 or >100bpm. In all cases, the heart rate was >100bpm when assessed using a stethoscope. The femoral pulse identified the heart rate as >100bpm in 20%, <100bpm in 35% and undetectable in 45%. The brachial pulse identified the heart rate >100bpm in 25%, <100bpm in 15% and undetectable in 60%. Umbilical cord palpation was more reliable with 55% identified as >100bpm, 25% <100bpm and 20% undetectable. This data suggests that in healthy newborn babies, brachial and femoral pulses are not reliable for determining heart rate. Umbilical pulsations must not be relied upon if low or absent. In assessing heart rate in newborn resuscitation only the stethoscope is likely to be completely reliable. In the absence of a stethoscope only the umbilical pulse should be used with an awareness of its limitations.