What is the normal respiratory rate in a newborn?

Normal Respiratory Rate in Newborns

The normal respiratory rate for a newborn is 40-60 breaths per minute during the first minutes to hours after birth, with a median of 42-46 breaths per minute in the first 24 hours of life. 1

Normal Range and Variations

• The American Heart Association and American Academy of Pediatrics guidelines define normal newborn respiratory rate as below 60 breaths per minute with no signs of respiratory distress 2
• Median respiratory rates in healthy term infants are:
  • 46 breaths/minute at 2 hours after birth
  • 42-44 breaths/minute at 4-24 hours after birth 1
• The 5th percentile is 30-32 breaths/minute
• The 95th percentile is 65 breaths/minute at 2 hours, decreasing to 58-60 breaths/minute thereafter 1

Factors Affecting Respiratory Rate in Newborns

Several factors can influence a newborn's respiratory rate:

1. Sleep state:

   • Sleeping newborns have significantly lower respiratory rates (mean 42 breaths/minute) compared to awake newborns (mean 61 breaths/minute) 3
   • Mean respiratory rate is 5.2 breaths/minute higher while awake than during sleep 1

2. Gender:

   • Boys have slightly higher respiratory rates (1.6 breaths/minute higher) than girls 1

3. Meconium staining:

   • Heavy meconium staining of amniotic fluid is associated with respiratory rates 3.1 breaths/minute higher 1

4. Crying:

   • Crying babies have lower respiratory rates (mean 51 breaths/minute) compared to awake, content babies (mean 61 breaths/minute) 3

Clinical Implications

• Tachypnea in newborns is defined as a respiratory rate ≥60 breaths per minute 4, 5
• Only 2-10% of healthy infants at any given age have respiratory rates ≥60/minute 5
• When counting respiratory rate, a full 60-second count is recommended, as shorter counting periods (especially 15-second counts multiplied by 4) can yield significantly different results 6, 5
• Respiratory rates show high variability even over short periods, so continuous or repeated monitoring is preferable to one-time measurements 6

Measurement Best Practices

• Count respiratory rate for a full 60 seconds for accuracy 6, 5
• Assess during a quiet state or sleep for most consistent results 1
• Be aware that observation and auscultation methods may yield slightly different results, with observation typically showing higher rates 5
• Consider the newborn's state (awake, asleep, crying) when interpreting respiratory rate values 3

Red Flags

• Persistent respiratory rate >60 breaths/minute with signs of respiratory distress warrants further evaluation 2
• Respiratory rates <30 breaths/minute (below 5th percentile) may indicate respiratory depression 1
• Irregular breathing patterns or significant variations in respiratory rate may indicate underlying pathology
• Respiratory rate should be assessed alongside other vital signs and clinical indicators of respiratory distress (nasal flaring, grunting, retractions)