Amin SB, et al. - Researchers strived to inspect the correlations between unbound bilirubin (UB) and total serum bilirubin (TSB), bilirubin:albumin molar ratio (BAMR), and bilirubin albumin binding affinity (Ka) as a function of gestational age (GA), in infants born at 24-33 weeks GA. A primary connection was revealed between the peak UB with a decrease in binding affinity in infants ≤30 weeks GA. Interventions targeting the improvement of the binding affinity could be vital for decreasing the risk of bilirubin-induced neurotoxicity.

Methods

• The plot of this research was a prospective observational study.
• TSB and UB were estimated twice daily at least 8 hours apart during the first postnatal week.
• In order to compute BAMR on each day, serum albumin was calculated.
• The highest UB on each day, corresponding TSB, and serum albumin assisted in measuring the Ka on each day.

Results

• Among the 166 infants, peak UB exhibited a prominent association with concomitant Ka (r = -0.44, P=.001) but not with concomitant TSB or BAMR after adjusting for GA.
• The multiple regression analyses revealed the presence of a notable link of concomitant Ka (-0.06, 95% CI -0.08 to -0.04, P=.0001), but not concomitant TSB or BAMR with peak UB after controlling for GA, birth weight, race, and sex.
• GA group served as an important effect modifier for the correlation between Ka and peak UB (0.03, 95% CI 0.02-0.04, P < .001).
• Interaction analyses illustrated that the tie-up between concomitant Ka and peak UB was vital for the 24-30 weeks GA group infants, but not for the 30^1/7-33 weeks GA group infants.