Relationship of Skin Reflectance and Serum Bilirubin: Full Term Caucasian Infants

Very little data concerning skin reflectance of the newborn has been published. The presence of cutaneous jaundice supports the qualitative relationship between skin color and serum bilirubin level. The present study was designed to obtain basic information concerning the reflectance of the newborn skin and its relationship to serum bilirubin level. Measurements of blanched skin were taken on the back of 30 White full-term infants. First order linear, multiple linear, and polynomial nonlinear regressions were performed on the spectral reflectance values over the range 400 to 750 nm at each of the wavelength band intervals (5 nm) with respect to serum bilirubin level. The best analysis results (R = 0.965) were obtained from a polynomial, non-linear regression of the double logarithm of the reflectance spectra for 5 wavelengths with respect to serum bilirubin concentration. This study shows that there is a strong relationship between spectral reflectance of the White full-term newborn skin and the serum bilirubin concentration.