Normal Respiratory Rate for Neonates
The normal respiratory rate for neonates is 30-60 breaths per minute, with tachypnea defined as ≥60 breaths per minute in infants less than 2 months of age. 1
Specific Reference Ranges by Time Period
First 24 Hours of Life
- Median respiratory rate: 46 breaths/minute at 2 hours of age, then 42-44 breaths/minute thereafter 2
- 95th percentile (upper limit): 65 breaths/minute at 2 hours, then 58-60 breaths/minute 2
- 5th percentile (lower limit): 30-32 breaths/minute 2
General Neonatal Period (Under 6 Months)
- Mean respiratory rate when awake: 61 breaths/minute 3
- Mean respiratory rate when sleeping: 42 breaths/minute 3
- Mean respiratory rate when crying: 51 breaths/minute 3
Clinical Thresholds for Abnormal Breathing
Tachypnea
- ≥60 breaths per minute in infants less than 2 months old indicates tachypnea and potential respiratory distress 1, 4
- This threshold is used by the World Health Organization as a diagnostic criterion for pneumonia and lower respiratory tract infections 1
Bradypnea
- <20 breaths per minute in infants under 1 year is defined as bradypnea and represents a critical warning sign requiring immediate medical attention 1
- This is an important criterion for detecting risk of serious injury 1
Factors Affecting Respiratory Rate
State-Dependent Variation
- Awake vs. sleeping: Respiratory rate is 5.2 breaths/minute higher when awake compared to sleep 2
- Crying: Paradoxically lowers respiratory rate by approximately 10 breaths/minute compared to awake-content state 3
Other Influencing Factors
- Sex: Boys have respiratory rates 1.6 breaths/minute higher than girls 2
- Meconium staining: Heavy meconium staining increases respiratory rate by 3.1 breaths/minute 2
- Mode of delivery: No significant difference between vaginal and cesarean deliveries 2
Measurement Considerations
Recommended Technique
- Duration: Count for a full 60 seconds, as the World Health Organization recommends 1
- Timing: Measure during sleep or quiet state when possible for most accurate baseline 2
- Method: Place stethoscope bell in front of nostrils and mouth, or observe chest/abdominal movements 2
Common Pitfalls
- Measurement variability: Neonates have highly irregular breathing patterns with significant breath-to-breath variation 5
- Observer error: Manual counting is imprecise and affected by intra-observer variation, requiring focused concentration 1
- State interference: Measurement is more difficult with crying, irritable, or moving infants 1
- Short counting periods: Counts shorter than 60 seconds show poor agreement with true respiratory rate, though the degradation is less than measurements taken 3 minutes apart 5
Clinical Context for Resuscitation
During neonatal resuscitation, assisted ventilation should be delivered at 40-60 breaths per minute 6, 7, 8. This rate is used when providing positive pressure ventilation and represents the physiologic target for supporting neonates who cannot maintain adequate spontaneous breathing 6, 7.
The wide intraindividual variation in respiratory rate (even within the normal range of 30-60 breaths/minute) means that continuous or repeated monitoring is preferable to single measurements when assessing neonatal respiratory status 5, 2.