Umbilical Cord and Neonatal Transthyretin and Their Relationship to Growth and Nutrition in Preterm Infants

Background: Transthyretin (TTR), also known as prealbumin, has been suggested as an indicator of protein and nutritional status. Objective: The aim of this study was to examine the maternal and umbilical cord (UC) TTR in relation to intrauterine growth, and the serum TTR of preterm infants in relation to nutritional status and growth. Methods: After application of exclusion criteria, 49 preterm infants (mean gestational age and birth-weight 32.9 +/- 2.9 weeks and 1822 +/- 556 g) were included in the study. Transthyretin was sampled at birth and on days 14, 28 or at discharge with growth parameters and nutritional laboratories. Results: Mean UC and maternal TTR were positively correlated (8.5 +/- 2.4 mg/dL and 20.4 +/- 7.0 mg/dL, r=0.31, P=0.07). Umbilical cord TTR was neither an index of maturity nor of intrauterine growth. Umbilical cord TTR was higher in females (9.4 +/- 2.6 versus 7.6 +/- 1.8 mg/dL, P=0.015). Maternal TTR was lower in twin pregnancies (16.8 +/- 4.9 versus 22.5 +/- 7.3 mg/dL, P=0.007). Although TTR levels gradually increased over time in correlation with post-menstrual and chronological ages (r=0.24, P=0.011 and r=0.40, P<0.001, respectively), there was no correlation to weight gain (r=0.10, P=0.41), nutritional status, protein intake, or laboratories. The only significant correlations were between TTR and glucose and triglycerides levels (r=0.51, P<0.001 for both). Conclusions: Although TTR levels increased over time, we could not demonstrate significant correlations between TTR and indices of the nutritional status in preterm infants at birth or during the neonatal course.