Serum thyroglobulin in newborns’ cord blood, in childhood and adolescence: a physiological indicator of thyroidal status

Abstract

Serum thyroglobulin (Tg) was measured in the cord blood of 635 newborns and serum thyroxine (T4) reverse triiodothyronine (rT3), TSH and T3 were measured in about 200 of them. Cord Tg was detectable in all newborns with a mean +/- SE value (50 +/- 1.3 ng/ml) higher than that found in the serum of adult subjects (n = 144; Tg = 13 +/- 1.1; p less than 0.0001). Cord Tg had a log-normal distribution. A low, but positive correlation was found between cord Tg and cord TSH (n = 242; r = 0.17; p less than 0.05) but not with cord T4 or cord rT3. Gestational age was negatively correlated with cord Tg or cord rT3 (rS = 0.97; p less than 0.01; rS = -0.89; p less than 0.02, respectively) while was positively correlated with cord T4 or cord TSH (rS = 0.85; p less than 0.05; rS = 0.86; p less than 0.01, respectively). Birth weight, maternal diabetes, induction of labor with oxitocin, cesarian section and newborns' illness showed no influence on cord Tg levels when considered alone, but decreased cord Tg levels were found in ill newborns delivered by cesarian section. On the contrary, increased cord Tg levels were present in cord blood of newborns who developed hypoglycemia soon after birth and in small for gestational age newborns. In 24 newborns studied daily for the first 6 days of life, serum Tg was always detectable with mean values not different from those found in the cord blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Gestation‐specific changes in maternal thyroglobulin during pregnancy and lactation in an iodine‐sufficient region in China: a longitudinal study

“…We found no correlation between cord blood Tg and cord TSH, which is not in agreement with the findings by Nohr et al . and Pezzino et al ., and there was no correlation between cord blood Tg and neonatal weight, which concurs with some previous findings …”

Relative Impact of Iodine Supplementation and Maternal Smoking on Cord Blood Thyroglobulin in Pregnant Women with Normal Thyroid Function

“…The main correlation for CB Tg in our population was with maternal smoking, while there was no correlation with maternal UIE in the third trimester, nor with other parameters that have been proposed by some authors, including mode of delivery [14] and gestational age [5]. Thus, it appears that smoking is the main factor explaining CB Tg in our population.…”

“…Although spot ioduria (urinary iodine excretion, UIE) is widely used to diagnose ID at the population level [1,2], serum thyroglobulin (Tg) has been proposed as a marker of ID [3], including in newborns [4,5]. Maternal iodine supplementation has been shown to improve maternal and cord blood (CB) thyroid tests in areas of moderate and severe ID [6,7].…”

Iodine content of infant formulas and iodine intake of premature babies: high risk of iodine deficiency.

“…In the present study increased thyroglobulin activities seem to be a clear sign of thyroid stimulation. 27 Iodine deficiency in preterm newborns increases the risk of hypothyroidism.25 Alterations in thyroid function in premature babies, leading to low circulating T4 or T3, have been associated with impaired neural maturation, as measured by nerve conduction velocity28 and by lower scores in the Bayley mental and motor scales.29 Iodine deficiency may well contribute to inadequate thyroid hormone activity in premature babies, but could easily be avoided.…”