Abstract
The serum concentrations of tri-iodothyronine (T3), thyroxine (T4), and thyrotrophin (TSH) were measured in 10 term newborn infants between birth and the age of 2 days by radioimmunoassay. The mean concentration of T3 in maternal serum was 1.62 mug/l, and it increased from the low cord blood level of 0-63 mug/l to the peak value of 1-76 mug/l within the first 2 hours of life. Mean serum T4 concentrations increased from the cord blood level of 145 mug/l to the peak value of 205 mug/l within the first 24 hours of life. The postnatal increase of the mean serum TSH concentrations from the cord blood level of 5-7 mU/l to the peak value of 20-6 mU/l within 2 hours was similar to the increase of T3. These data confirm earlier reports which show that T3 secretion is low at birth and TSH secretion is stimulated strongly but transiently after birth, and that the low T3 secretion is rapidly normalized in 2 hours along with the TSH release. Because of these strong and rapid changes, we recommend screening of the function of the pituitary-thyroid axis in neonates after the age of 24 hours.
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Selected References
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- Dussault J., Row V. V., Lickrish G., Volpé R. Studies of serum triiodothyronine concentration in maternal and cord blood: transfer of triiodothyronine across the human placenta. J Clin Endocrinol Metab. 1969 Apr;29(4):595–603. doi: 10.1210/jcem-29-4-595. [DOI] [PubMed] [Google Scholar]
- Fisher D. A., Dussault J. H., Hobel C. J., Lam R. Serum and thyroid gland triiodothyronine in the human fetus. J Clin Endocrinol Metab. 1973 Feb;36(2):397–400. doi: 10.1210/jcem-36-2-397. [DOI] [PubMed] [Google Scholar]
- Fisher D. A., Odell W. D. Acute release of thyrotropin in the newborn. J Clin Invest. 1969 Sep;48(9):1670–1677. doi: 10.1172/JCI106132. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hotelling D. R., Sherwood L. M. The effects of pregnancy on circulating triiodothyronine. J Clin Endocrinol Metab. 1971 Nov;33(5):783–786. doi: 10.1210/jcem-33-5-783. [DOI] [PubMed] [Google Scholar]
- Hüfner M., Hesch R. D., Heinrich U., Lüders D. Plasma triiodothyronine at the end of pregnancy, in the cord blood and in the first days of the newborn. Z Kinderheilkd. 1973;114(4):301–304. doi: 10.1007/BF00569922. [DOI] [PubMed] [Google Scholar]
- Klein A. H., Agustin A. V., Foley T. P., Jr Successful laboratory screening for congenital hypothyroidism. Lancet. 1974 Jul 13;2(7872):77–79. doi: 10.1016/s0140-6736(74)91637-7. [DOI] [PubMed] [Google Scholar]
- Larsen P. R. Direct immunoassay of triiodothyronine in human serum. J Clin Invest. 1972 Aug;51(8):1939–1949. doi: 10.1172/JCI107000. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lieblich J. M., Utiger R. D. Triiodothyronine in cord serum. J Pediatr. 1973 Feb;82(2):290–292. doi: 10.1016/s0022-3476(73)80172-6. [DOI] [PubMed] [Google Scholar]