Noninvasive Assessment of Bilirubin Levels in Newborn Infants With Dark Skin Pigmentation

Visual assessment of neonatal jaundice, especially in infants with dark skin pigmentation, is imprecise, and better tools are needed in low-resource settings. We aimed to assess the accuracy of the Picterus smartphone app in estimating total serum bilirubin (TSB) in darkly pigmented newborn infants, compared with a transcutaneous bilirubin (TcB) device.

A prospective study was conducted in Botswana, where term newborn infants aged 1-14 days were recruited. Bilirubin levels were measured using the Picterus app and a TcB device and compared with laboratory-measured TSB values.

Complete datasets were available for 123 participants. The Pearson's R correlation with TSB was 0.66 (95% confidence interval (CI) 0.55-0.75) for the Picterus app, and 0.84 (95% CI 0.78-0.89) for TcB. For TSB ≥ 250 μmol/L (14.6 mg/dL), the Picterus app tended to underestimate while the TcB overestimated TSB values. For TSB values ≥ 250 μmol/L (14.6 mg/dL), the Picterus app showed 64% sensitivity, compared with 95% for TcB.

The Picterus app underestimated high TSB values, reducing its screening sensitivity. The app, however, holds potential as an accessible screening tool but requires optimization for darkly pigmented newborn infants. The TcB device proved reliable for hyperbilirubinemia screening in this population.