Neonatal Thyroidal Hyperactivity

Fisher, Delbert A.; Oddie, T. H.

doi:10.1001/archpedi.1964.02080060576004

Cited by 36 publications

(14 citation statements)

References 23 publications

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“…This observation has been amply confirmed (2)(3)(4)(5)(6), and increases in triiodothyronine-mI erythrocyte or resin uptake (4,(7)(8)(9) and in free thyroxine (6) have also been demonstrated. These data indicate and quantitative measurements have confirmed (5) that alterations in maximal binding capacity of thyroxine-binding serum proteins are not responsible for the neonatal hyperthyroxemia.…”

Section: Introductionmentioning

confidence: 62%

“…In agreement with this hypothesis, we (11) and Utiger, Wilber, Cornblath, Harm, and Mack (12) have previously reported that TSH concentrations are elevated in the sera of newborn infants during the early hours of extrauterine life. Fisher, Oddie, and Makoski (4,13) also reported that the degree of hyperthyroxinemia can be significantly reduced by warming the infant during the first 48 hr of life and suggested that neonatal hyperthyroxinemia may be, at least in part, a response to extrauterine cooling.…”

Section: Introductionmentioning

confidence: 99%

“…These data indicate and quantitative measurements have confirmed (5) that alterations in maximal binding capacity of thyroxine-binding serum proteins are not responsible for the neonatal hyperthyroxemia. An associated high rate of thyroidal radioiodine clearance in the newborn led Fisher, Oddie, and Burroughs (4,10) to suggest that the hyperthyroxinemia was the result of a high rate of thyrotropin (TSH) release. In agreement with this hypothesis, we (11) and Utiger, Wilber, Cornblath, Harm, and Mack (12) have previously reported that TSH concentrations are elevated in the sera of newborn infants during the early hours of extrauterine life.…”

Section: Introductionmentioning

confidence: 99%

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Acute release of thyrotropin in the newborn

Fisher¹,

Odell²

1969

J. Clin. Invest.

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227

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A B S T R A C T Measurements of serum thyrotropin(TSH) concentrations were conducted in maternal and fetal blood during labor and delivery and the early postnatal and neonatal periods. Mean TSH concentration was significantly higher in cord blood (9.5 AU/ml) than maternal blood (3.9 /U/ml), a finding suggesting a fetalmaternal TSH gradient at term. Serum TSH concentration in the newborn increased rapidly to mean levels of 60 AU/ml at 10 min and 86 AU/ml at 30 min of age.Between 30 min and 3-4 hr serum levels decreased rapidly, then fell more gradually to a mean concentration of 13 AU/ml at 48 hr. The half-time of the decrease in serum TSH concentration between 30 and 90 min was 77 min, a value slightly greater than the half-time of disappearance of radioiodinated TSH measured in adults. This indicates that the early high rate of TSH secretion in the newborn ceases by 30 min, and that the rapid rise and fall in serum TSH concentrations may represent release of stored pituitary TSH. A more chronic TSH hypersecretion persisted throughout the first 24-48 hr of extrauterine life. Measurements of serum PBI concentrations were conducted in a separate group of maternal and cord blood samples and in the newborn infants during the first 48 hr of extrauterine life to relate the TSH and serum hormonal iodine concentration changes. Serum protein-bound iodine (PBI) concentrations were similar in maternal and cord blood, increased significantly by 4 hr of age in the newborn, and peaked at about 24 hr, presumably in response to the TSH hypersecretion. The pattern of TSH hypersecretion was similar in infants delivered vaginally and by caesarean section. Maternal serum TSH concentrations were stable throughout the perinatal period. Warming the infants at 99-103'F during the first 3 hr of life did not prevent the early, acute release of thyrotropin. Cooling of warm infants at room temperature (72-780F) between 3 and 4 hr resulted in a decrease in mean rectal temperature of 3.3XF and produced a significant increment in serum TSH concentration. These data suggest

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Section: Introductionmentioning

confidence: 62%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Acute release of thyrotropin in the newborn

Fisher¹,

Odell²

1969

J. Clin. Invest.

Self Cite

227

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“…During the first few days of postnatal life serum hormonal iodine values have been shown to increase significantly [4,9,10,13,14,16]. Absence of clinical signs of hyperthyroidism in the presence of laboratory findings suggestive of thyroid hyperactivity continues to be unexplained.…”

Section: Introductionmentioning

confidence: 99%

Serum Triiodothyronine, Total Thyroxine, and Thyroxine to Triiodothyronine Ratios in Paired Maternal-Cord Sera and at One Week and One Month of Age

et al. 1973

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ExtractTwenty-seven paired maternal-cord sera were analyzed for serum triiodothyronine (T3), total serum thyroxine (TT4), and maximum thyroxine globulin binding capacity (TBG cap.). In 17 of the infants the same studies were repeated at 1 week of age and in 10 of the 17 at 1 month. The mean T 3 value for the cord sera was 73.1 ± 20.4 ng/100 ml while the mean value for the maternal sera was 204 ± 49.2. The difference in the mean values was highly significant (P < 0.001). The maternal T 3 values are comparable with those of nonpregnant control subjects; those of cord blood fall below normal values. No statistically significant difference was found between the TT4 and TBG cap. values for cord and maternal sera. Both values were higher than the normal nonpregnant control values. At 1 week of age the serum T 3 levels had increased to a mean of 208.4 ± 40.9 ng/100 ml. This mean is significantly different from the one observed in cord sera (P < 0.001). A significant increase in the TT 4 values, mean 12.53 ± 2.2 Mg/100 ml (P < 0.01), was observed by the end of the 1st week. TBG cap. did not change significantly between birth and 1 week of age; by the end of the 1st month of life the serum TT 4 had decreased significantly to a mean of 9.5 ± 2.7 Mg/100 ml (P < 0.05), while the serum T 3 was maintained at a mean level of 228.2 ± 16.9 ng/100 ml, a value not significantly different from the one observed at 1 week of age. SpeculationThe extremely low levels of T 3 in the cord blood in the presence of TT 4 and TBG cap. values equal to those of the maternal blood suggest minimal materno-fetal placental transfer of T 3 . We have postulated that the low fetal T3 is responsible for the high levels of pituitary thyrotropic hormone (TSH) present in cord blood and early in the postnatal period and that the high levels of TT 4 with normal T 3 levels observed by the end of the 1 st week of life indicate defective peripheral deiodination of thyroxine (T 4 ) to T 3 and account for the lack of signs and symptoms of hyperthyroidism. By the end of 1 month of age TT 4 and T 3 values are within normal ranges, which indicates maturation in the metabolic pathway of T 4 and T 3 . 706T 3 , TT4, and T4/T3 in maternal-cord sera 707

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“…The role of thyroid hormones in heat production (Swanson, 1957), mobilization of fatty acid (Debons and Schwartz, 1961), would support the hypothesis of Fisher and Oddie (1964) that the acute release of TSH was in part due to extrauterine cooling.…”

Section: Methodsmentioning

confidence: 87%

Histological Structure of the Thyroid Gland in the Newborn

Larroche¹

1976

Neonatology

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Histological features of the thyroid gland in the newborns have been described under several circumstances; gestational age, length of survival, and under particular clinical status such as hypotrophy (intrauterine growth retardation), Cesarean section delivery and hydrops fetalis. Gestational age does not modify significantly the histological aspect of the thyroid, while birth process and adjustment to extrauterine life induce dramatic changes such as severe depletion of colloid for about 24 h, followed by a massive repletion after the first day of life. A few exceptions to this phenomenon are described. Thyroid glands of hypotrophic infants and of infants delivered by cesarean section exhibit colloid-filled vesicles already within the first day. Thyroid glands of hydrops fetalis have a reverse tendency. This phenomenon might be secondary to multiple exchange transfusions.

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Neonatal Thyroidal Hyperactivity

Cited by 36 publications

References 23 publications

Acute release of thyrotropin in the newborn

Acute release of thyrotropin in the newborn

Serum Triiodothyronine, Total Thyroxine, and Thyroxine to Triiodothyronine Ratios in Paired Maternal-Cord Sera and at One Week and One Month of Age

Histological Structure of the Thyroid Gland in the Newborn

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