One-hour lung ultrasound found a signal, not a screening rule

In 121 initially stable newborns, a score of 9 had 89.3% sensitivity and 88.2% specificity for oxygen use within 48 hours. The same cohort set and tested the cutoff.

A lung ultrasound score measured at one hour separated initially stable newborns who later received free-flow oxygen from those who did not. The association is worth validating. The reported score-9 cutoff is not yet a screening rule because the same small, single-center cohort produced and tested it.

The cohort

This prospective observational study enrolled 121 consecutive singleton newborns at 35 weeks' gestation or later in one tertiary academic hospital from December 2025 through February 2026. Eligible infants were breathing spontaneously, had a heart rate above 100 beats/min, had no significant respiratory distress, and had received neither positive-pressure ventilation nor CPAP during the first hour.

The attending neonatologist decided when to start oxygen using routine assessment and pulse oximetry. Local practice used persistent preductal oxygen saturation below 90% together with clinical judgment, but the study imposed no rigid treatment algorithm. The hidden ultrasound result did not guide care.