Ultrasound Image Patterns Right After Birth Can Predict Healthy Neonates – A Nested Case-Control Study

Abstract Background Lungultarsound(LUS) is widely used to diagnose neonatal lung diseases, yet image patterns on intrauterine to extrauterine stage(right after birth), of which impairment is well related to lung disease, remains unclear. Objectives To identify these image patterns that can distinguish healthy infants from infants with lung disease.Methods This is a nested case-control study in a top-ranking obstetrics hospital in China, between 1 January 2020 to 1 April 2020. Infants transferred to the NICU after birth who had LUS obtained at 0.5, 1, 2, 4, 6 hours time intervals were enrolled. Confirmed by 3-day follow-up, case and control groups contains 22 patients and 473 healthy infants. Their GA ranges from 33.5 to 41.0 weeks. A newly designed protocol was used to capture the LUS image. The image patterns and their variations were shown and categorized as high and low-risk groups. The predictive value for healthy infants and patients were calculated. Results Low-risk patterns, accompanied with no high-risk ones, typically appeared in healthy infants (specificity=86.4%, PPV=99.0%), whereas four high-risk patterns could be seen in both healthy infants and patients (specificity=62.4%, PPV=9.6%). High-risk patterns were more likely to be pathological signs when appearing at the oxter and lower back and to be physiological signs when appearing at the prothorax. Conclusions LUS is valid to differentiate healthy infants from potential patients shortly after birth. Infants with low-risk patterns only are highly likely to be healthy, whereas infants with high-risk patterns have a risk for respiratory issues but need prolonged monitoring to confirm.