Newborns requiring resuscitation: Two thirds have heart rate ≥100 beats/minute in the first minute after birth.

AIM: The aim was to study the prevalence of bradycardia at birth in newborns requiring positive pressure ventilation (PPV), distribution of first measured heart rate (HR), changes in HR before start of PPV and HR response to PPV.

METHODS

A population-based study including newborns ≥30 weeks' gestation receiving PPV at birth. HR was captured immediately after birth and continuously throughout resuscitation using the dry-electrode ECG device NeoBeat. Time of birth was registered in the Liveborn app. Provision of PPV was captured by video.

RESULTS

We included 98 newborns receiving PPV at birth. Among newborns with HR measured within 60 s after birth, median (quartiles) first HR was 112 (84, 149) bpm recorded 19 (14, 37) s after birth, of which 33% had first HR <100 and 10% had first HR <60 bpm respectively. First HR was widely distributed. Median HR at start PPV 69 s after birth was 129 bpm. In newborns with an initial low HR, HR typically remained low for 20 s of PPV before increasing rapidly over the next 20-30 s.

CONCLUSIONS

First measured HR was ≥100 bpm in two thirds of newborns receiving PPV. In bradycardic infants, HR did not increase until after 20 s of PPV.