Although free bilirubin concentration is one of the main contributors for kernicterus development, laboratory methods for its determinations have not been standardized. This study goal is to verify if biliribin to albumin molar ratio (B/A) is a better predictor of free bilirubin (FB) concentration than total serum bilirubin (B) in jaundiced newborn infants. 114 jaundiced newborn infants without perinatal asphyxia, hypotermia, hypoglicemia, hypoxia, acidosis, sepsis and albumin-binding drugs use were studied. Patients were divided in two groups: term (n=49, BW=3085±408g; GA=39.1±1.0 w; 55% male; 3.1±0.9 days of life) and preterm(n=65; BW=1835±381g; GA=33.7±1.5 w; 45% male; 4.0±1.6 days of life).

Serum albumin-A (bromcresol green), B (Jendrassik-Gróf) and FB(horseradish peroxidase) were measured and the following parameters were compared between term and preterm sera: B × FB and B/A × FB. Regression lines were drawn for B × FB and B/A × FB and Pearson correlation coeficients were determined. Significance was considered when p< 0.05. Table

Table 1
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A significant positive moderate correlation was demonstrated between B× FB and B/A × FB for both preterm and term newborn infants.

Bilirubin to albumin molar ratio is not a better predictor of free bilirubin than total bilirrubin in jaundiced preterm and term newborn infants. (Funded by Trilab Diagnóstica Ltd.)