A study on transplacental transfer of thyroid hormones in pregnant Nigerian women of Jos-Plateau State.
Knowledge of transplacental passage of thyroid hormones in pregnant women is very scanty. Seventy paired 'maternal-cord' blood samples were obtained at term (40 week) deliveries from the Nigerian women from Jos Plateau and its environment, and the level of serum T4, T3, TSH, TBG and TBK (thyroxine binding capacity) were determined by 'ELISA' technique (Boehringer). The serum level of FT41 (free thyroxine index) was determined subsequently by dividing the serum values of T4 with those of TBK. The results obtained were compared with those derived from a similar group assessed among white Americans, as well as with an age-matched non pregnant control group selected from Jos metropolis. Results show that the level of thyroid activity in the present group of 'mothers and neonates' assessed were lower compared to the level seen in the corresponding American group. Correlation studies carried out in this work indicated that the maternal and corresponding neonates have significant degree of positive correlations between the serum levels of T4 (r > .9; p < .005); FT4I (r > .88; p < .005); TBK (r > .8; p < .005); TBG (r > .89; p < .005) and TSH (r > .87; p .005), while T3 did not show any correlation. It is concluded, that during pregnancy there is probably significant transplacental passage of iodine (I) from the mother to the growing foetus, in an attempt to build the necessary foetal Iodine pool, and TRH (thyrotrophin releasing hormone) probably acts as mediator between the foetal and maternal 'hypothalamus--pituitary--thyroid' axis, which are, otherwise independent of each other.
Das
S C
SC
Department of Chemical Pathology, Faculty of Medical Sciences, University of Jos, Plateau State-Nigeria.
Isichei
U P
UP
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D006801:Humans; D016555:Matched-Pair Analysis; D008431:Maternal-Fetal Exchange; D009549:Nigeria; D011247:Pregnancy / Q000097:blood*; D013963:Thyroid Hormones / Q000097:blood*; D014481:United States; D014504:Urban Health; D044465:White People
D013963:Thyroid Hormones