Serum levels of thyroid hormone-binding proteins in fullterm(FT), small-for-gestational age(SGA) and preterm(PT) newborn babies

Abstract

We have previously reported our findings of significantly different serum levels of thyroid hormones in FT, SGA and PT newborns. Studies on hormone-binding proteins in these groups are still needed. Therefore, using Laurells rocket immunoelectrophoresis thyroxine-binding globulin (TBG),-prealbumin (TBPA) and albumin (Alb) were determined in sera of 125 FT, 29 SGA and 21 PT babies aged 0-6 days. Significantly different serum levels of corresponding proteins appeared between the 3 groups of newborns. The ratios between serum concentrations of thyroid hormone and hormone-binding protein, however, did also differ for FT, SGA and PT babies indicating that differences in se-TBG, se-TBPA and se-Alb concentrations only in part might explain the various thyroid hormone levels observed in FT, SGA and PT newborn babies.