Second-Trimester Placental and Thyroid Hormones Are Associated With Cognitive Development From Ages 1 to 3 Years

Abstract

Adequate maternal thyroid hormone is necessary for fetal brain development. The role of placental hCG in ensuring the production of thyroid hormone is less well understood. The objective of the study was to evaluate 1) associations of placental hCG and its subunits, and maternal thyroid hormone in the second trimester, and 2) the single and joint effects of thyroid and placental hormones on cognitive development and communication at 1 and 3 years of age. 50 subjects (5%) were selected from the CANDLE pregnancy cohort in Memphis, TN with recruitment from 2006 to 2011, to equally represent male and female fetuses. Subjects were 68% Black and 32% White. Hormones measured were maternal thyroid [TSH and free T4 (FT4)] and placental hormones [human chorionic gonadotropin (hCG), its hyperglycosylated form (hCG-h) and free α- (hCGα) and β-subunits (hCGβ)] in maternal serum (17-28 weeks). The primary outcome measurement was the Bayley’s Scales of Infant and Toddler Development. All forms of hCG were negatively associated with FT4 and not associated with TSH. hCGα was associated with cognitive development at 1 year of age and jointly interacted with TSH to predict cognitive development at 3 years of age. This pilot study added insight on the thyrotropic actions of hCG in the second trimester, and on the significance of this mechanism for brain development. More research is warranted to elucidate differences between hCGα, hCGβ, and hCG-h in relation to thyroid hormone regulation and child brain function.

Associations of Serum Perfluoroalkyl Substances and Placental Human Chorionic Gonadotropin in Early Pregnancy, Measured in the UPSIDE Study in Rochester, New York

“…The details of analytical methods have been described previously. 60 Serum samples were diluted 1:100 before analysis (1 part of sample and 100 parts of dilution buffer). In brief, intact hCG ( ) was measured using a sandwich-type time-resolved immunofluorometric assay (IFMA) specific for intact dimer.…”

Application of 4-way decomposition to the analysis of placental-fetal biomarkers as intermediary variables between maternal body mass index and birthweight

“…Total hCG (intact hCG which includes the α and β -subunits) and/or hCG- β were measured depending on which laboratory did the analysis. When measured together, serum intact hCG and hCG- β are correlated with R value = 0.96) and therefore were treated as equivalent measures ( 27 ). Data on hCG and the other placental-fetal biomarkers (first trimester PAPPA, second trimester hCG, Inhibin-A, Estriol, and Alphafeto protein) were abstracted from the prenatal medical record or obtained directly from the laboratories that conducted the analyses.…”