[Correlation between transcutaneous bilirubinometry and serum bilirubin in newborns ≥ 35 weeks].

Clinical control and monitoring of bilirubin in the neonatal stage are essential to avoid toxicity in the central nervous system.
Objective: to determine the correlation between transcutaneous bilirubin (TcB) and total serum bilirubin (TSB) levels in newborns ≥ 35 weeks.
Patients and Method: observational, cross-sectional, analytical, retrospective study that included 90 neonates of gestational age ≥ 35 weeks with mucocutaneous jaundice who underwent TcB and TSB measurement simultaneously between June 1, 2022, and January 31, 2023. Both variables were compared, determining their correlation.
Results: the validity indicators were analyzed, obtaining 100% sensitivity and negative predictive value. The mean of TcB determinations was 14.84 mg/dl ± 2.27 and that of TSB was 13.1 mg/dl ± 2.39. The correlation obtained indicates that both variables are related, which is a direct correlation and, according to the prediction equation, there is an appropriate correlation between them. It was determined that TcB overestimated TSB in 95.56% of the determinations, and underestimated TSB in the rest (4.44%). Simultaneous measurements of TcB and TSB were different in all determinations with a mean difference of 1.72 ± 1.48.
Conclusions: the non-invasive TcB method can be used as an initial screening tool for the neonatal population ≥ 35 weeks, given its adequate sensitivity and negative predictive value.