J Korean Pediatr Soc.  1994 Jun;37(6):832-841.

Normal Blood TSH, T4 Levels in Neonates as Determined by Screening Test

• Cha IA
• Kim KS
• Kim KS
• Kim YW
• Kim KB

Abstract

In 1,146 term neonates without perinatal problems who were born in Kwangju Christian Hospital, blood TSH levels were measured by immunoradiometric assay. In 397 term neonates among them, blood T4 levels were measured by radioimmunoassay in same specimens. 1) In normal neonates aged 3~5 days, 6~10 days, 11~20 days and 21~28 days, the TSH levels were 8.88+/-5.21(mean+/-SD), 9.44+/-5.16, 9.69+/-4.98, 11.96+/-3.75 IU/ml and the T4 levels were 11.41+/-2.79, 11.37+/-2.82, 11.19+/-2.63, 10.51+/-2.99 g/dl respectively. 2) No significant sex difference in TSH level was found in each age group, and TSH level did not correlate with birth weight. In neonates delivered by Cesarean section, TSH levels were lower than those of the normally delivered. 3) T4 levels did not differ between both sexes, and between types of delivery in each age group, and nor did it correlate with birth wweight 4) If the recall rate should be set at 0.2% of the total, TSH levels above 26.9 IU/ml would be required to recall for serum sampling. TSH level above 2 SD was 19.7 IU/ml. Cutoff points of T4 levels at 1.5 SD and 2 SD were 5.8 and 7.2 g/dl respetively, and the lowest 10th percentile was 7.4 g/dl.

MeSH Terms

Birth Weight
Cesarean Section
Female
Gwangju
Humans
Immunoradiometric Assay
Infant, Newborn*
Mass Screening*
Parturition
Pregnancy
Radioimmunoassay
Sex Characteristics