TY - JOUR
T1 - Human fetal and cord serum thyroid hormones: developmental trends and interrelationships
AU - Hume, Robert
AU - Simpson, Judith
AU - Delahunty, Caroline
AU - van Toor, Hans
AU - Wu, S. Y.
AU - Williams, Fiona L. R.
AU - Visser, Theo J.
AU - Scottish Preterm Thyroid Group
N1 - dc.publisher: Endocrine Society
dc.description.sponsorship: Commission of European Community (QLG3-2000-00930)
Chief Scientist’s Office Scottish Executive (K/MRS/50/C741)
Wellcome Trust
Tenovus (Scotland)
Paediatric Metabolic Fund
PY - 2004/8
Y1 - 2004/8
N2 - Thyroid hormone is essential for fetal and neonatal development in particular of the brain, but little is known about regulation of fetal thyroid hormone levels throughout human gestation. The purpose of this study was to clarify developmental trends and interrelationships among T-4, free T-4 (FT4), thyroxine-binding globulin (TBG), TSH, T-3, rT(3), and T-4 sulfate (T4S) levels in cord and fetal blood sera ( n = 639, 15 - 42 wk gestation) and correlate infant levels ( 23 - 42 wk gestation) to maternal values ( n = 428, 16 - 45 yr) and those of nonpregnant women ( n = 233, 16 - 46 yr). In cord and fetal serum, T4, T3, and TBG levels increase with gestation until term; TSH, FT4, T4S, and rT(3) levels increase and peak in the late second/early third trimester and then decline to term; T-4/TBG ratios increase until late second trimester and plateau to term. Term cord sera TSH, TBG, and all iodothyronine levels, except T-3, are higher than nonpregnant women. In the third trimester, cord serum FT4, TSH, rT(3), and T4S levels are also higher than corresponding maternal levels, but T-4, T-3, and TBG levels are lower than maternal values. The late second/early third trimester is a critical transition period in fetal thyroid hormone metabolism, which may be interrupted by preterm birth and contribute to postnatal thyroid dysfunction.
AB - Thyroid hormone is essential for fetal and neonatal development in particular of the brain, but little is known about regulation of fetal thyroid hormone levels throughout human gestation. The purpose of this study was to clarify developmental trends and interrelationships among T-4, free T-4 (FT4), thyroxine-binding globulin (TBG), TSH, T-3, rT(3), and T-4 sulfate (T4S) levels in cord and fetal blood sera ( n = 639, 15 - 42 wk gestation) and correlate infant levels ( 23 - 42 wk gestation) to maternal values ( n = 428, 16 - 45 yr) and those of nonpregnant women ( n = 233, 16 - 46 yr). In cord and fetal serum, T4, T3, and TBG levels increase with gestation until term; TSH, FT4, T4S, and rT(3) levels increase and peak in the late second/early third trimester and then decline to term; T-4/TBG ratios increase until late second trimester and plateau to term. Term cord sera TSH, TBG, and all iodothyronine levels, except T-3, are higher than nonpregnant women. In the third trimester, cord serum FT4, TSH, rT(3), and T4S levels are also higher than corresponding maternal levels, but T-4, T-3, and TBG levels are lower than maternal values. The late second/early third trimester is a critical transition period in fetal thyroid hormone metabolism, which may be interrupted by preterm birth and contribute to postnatal thyroid dysfunction.
KW - Fetal blood chemistry
KW - Postpartum period blood
KW - Thyroid hormones blood
U2 - 10.1210/jc.2004-0573
DO - 10.1210/jc.2004-0573
M3 - Article
SN - 0021-972X
VL - 89
SP - 4097
EP - 4103
JO - Journal of Clinical Endocrinology & Metabolism
JF - Journal of Clinical Endocrinology & Metabolism
IS - 8
ER -