Oxygen Saturation and Heart Rate Ranges in Very Preterm Infants Requiring Respiratory Support at Birth

To evaluate the changes in preductal oxygen saturation (SpO₂) and heart rate in preterm infants receiving continuous positive airway pressure (CPAP) and/or positive-pressure ventilation (PPV) at birth.

A prospective observational study at birth of infants aged <32 weeks separated into 2 gestational age (GA) groups: 23^0/7-27^6/7 weeks (group 1) and 28^0/7-31^6/7 weeks (group 2). Infants received delayed cord clamping (DCC) in accordance with institutional protocol. CPAP and/or PPV was applied at the clinical team's discretion. SpO₂ and heart rate were recorded every minute for 10 minutes. Preductal SpO₂ was targeted according to published nomograms. For heart rate, the goal was to maintain a stable heart rate >100 bpm.

The study cohort comprised 96 group 1 infants (mean GA, 26 ± 1 weeks; mean birth weight, 818 ± 208 g) and 173 group 2 infants (mean GA, 30 ± 1 weeks; mean birth weight, 1438 ± 374 g). In general, infants requiring respiratory support reached target values for heart rate and SpO₂ more slowly than the published nomograms for spontaneously breathing preterm infants without respiratory support. Infants receiving CPAP reached SpO₂ and heart rate targets faster than infants receiving PPV. In group 1, but not group 2 infants, DCC resulted in higher SpO₂ and heart rate.

SpO₂ and heart rate do not quickly and reliably reach the values achieved by spontaneously breathing preterm infants not requiring respiratory support.