Neonates thyroid function

Koga Y, Sano H, Kikukawa Y, Ishigouoka T, Kawamura M. Effect on neonatal thyroid function of povidone-iodine used on mothers during perinatal period. J Obstet Gynaecol 1995 21(6) 581-5. 

Gruters A, Krude H, Biebermann H, et al. Alterations of neonatal thyroid function. Acta Paediatr Suppl 1999 88 17-22. 

Since it has been suggested that the fetus and infant might be more susceptible to the adverse effects of perchlorate on neonatal thyroid function, the perchlorate content of breast milk and infant formulae was assessed. We found that perchlorate was detected in all 49 breast milk samples (median, 9.1pg/l) and in 17 infant formulae (median, 1.5pg/l). There was no correlation between breast milk perchlorate and breast milk iodine content, even in those 27 samples with perchlorate concentrations greater than lOpg/1 (Pearce et al., 2007 b). This is in contrast to the data reported by Kirk et al. (2005) in 6 breast milk samples in which there was a negative correlation between perchlorate and iodine content. Perchlorate has also been detected in cows milk in the US (5.9 1.8 o,g/l) (Kirk et al., 2005) and in Japan (9.4 2.7 J,g/l) (Dyke et al., 2007). 

Figure 50.4 Proposed protocols for monitoring neonatal thyroid function under special circumstances.

Extensive work has been performed to assess neonatal thyroid functional status in communities in iodine-deficient parts of the country. KochupiUai et al. (1986) showed that the incidence of neonatal hypothyroidism varied from 7.5% to 13.3% in the highly endemic sub-Himalayan districts of Gonda, Gorakhpur and Deoria. In comparison, the incidence of neonatal hypothyroidism in Delhi was 0.6%, while coastal Kerala, which was not endemic for goiter, had a neonatal hypothyroidism incidence of 0.12%, comparable with the congenital hypothyroidism rates of 0.02—0.05% reported in iodine-sufficient countries. 

Kochi MH, Kaloudis EV, Ahmed W, Moore WFl. Effect of in utero exposure of iodinated intravenous contrast on neonatal thyroid function. J Comput Assist Tomogr 2012 Mar-Apr 36(2) 165-9. 

Recently, data on iodine nutrition and neonatal thyroid function in Europe, confirm the continuing presence of severe iodine deficiency affecting neonatal thyroid function and hence a threat to early brain development. ... 

Data on neonatal thyroid function was analysed for four cities where enough new-borns (30,000 - 102,000) had been assayed. The incidence of permanent sporadic hypothyroidism was very similar in the four cities but the rate of transient hypothyroidism was much greater in Freiberg, associated with the lowest level of urine iodine excretion, than in Stockholm, with intermediate findings from Rome and Brussels. These data confirm the significance of low iodine intake for neonatal thyroid function. 

P. Bourdoux, Maternal and neonatal thyroid functions at birth in conditions of marginally low iodine intake, J Clin Endocrinol Metab. (September 1992 in press),... 

NEONATAL THYROID FUNCTION IN SEVERE ENDEMIC GOITER AREAS... 

NATIONAL PROGRAMME OF IODINE PROPHYLAXIS AND NEONATAL THYROID FUNCTION... 

Data on iodine nutrition and neonatal thyroid function in Europe confirm the continuing presence of severe iodine deficiency. This affects neonatal thyroid function and hence represents a threat to early brain development. These data have raised great concern about iodine deficiency, which is also heightened by awareness of the hazard of nuclear radiation with carcinogenic effects following the Chernobyl disaster in the former Soviet Union (Table 1). 

Kreutler PA, Varbanov V, Goodman W, et al. 1978. Interactions of protein deficiency, cyanide, and thiocyanate on thyroid function in neonatal and adult rats. Am J Clin Nutr 31 282-289. 

Tellez R, Chacon PM, Crump KS, Blount BC, Gibbs JP (2005) Chronic environmental exposure to perchlorate through drinking water and thyroid function during pregnancy and the neonatal period. Thyroid 15 963-975... 

Orme J, Taylor DH, Laurie RD, et al Effects of chlorine dioxide on thyroid function in neonatal rats. J Toxicol Environ Health 15 315-322, 1985... 

Neonatal goiter caused by the use of potassium iodine as an expectorant during pregnancy has been reported (67). The neonate, a girl, had acute hypothyroidism, with myxedema and respiratory distress. She was given levothyroxine for 6 months, with complete normalization of thyroid function. 

Arena J, Eguileor I, Emparanza J. Repercusion sobre la function tiroidea del RN a termino de la aplicacion de povidona iodada en el munon umbilical. [Repercussion of the application of povidone-iodine to the umbilical stump on thyroid function of the neonate at term.] An Esp Pediatr 1985 23(8) 562-8. 

The major adverse effect on the fetus is altered thyroid function (SEDA-13, 141 SEDA-14, 149 SEDA-19, 194 SEDA-20, 176). There have been individual reports of neonatal hyperthyroxinemia (79), goiter (80), and hypothyroidism (81). In the patient with goiter there was associated hypotonia, bradycardia, large fontanelles, and macroglossia (80). 

Dembinski J, Arpe V, Kroll M, Hieronimi G, Bartmann P. Thyroid function in very low birthweight infants after intravenous administration of the iodinated contrast medium iopromide. Arch Dis Child Fetal Neonatal Ed 2000 82(3) F215-7. 

Vogiatzi MG. Frequency and necessity of thyroid function tests in neonates and infants with congenital hypothyroidism. Pediatrics 1997 100 E6. 

Iodide requirements in extreme preterm infants are particularly difficult to assess as they have very limited thyroidal iodine reserves (Etling, 1977 Costa et ai, 1986 van den Hove et at, 1999), and they are also susceptible to iodine toxicity and hypothyroidism if too much iodide is given (L AUemand et ai, 1987). There are no current pubhshed studies indicating the iodine requirements of extreme preterm infants, sick infants, or infants in the early neonatal period. Iodide requirements of these infants should therefore be assessed through carefully-controlled studies that avoid toxicity, but also test the efficacy of iodide supplementation in optimizing thyroid function. 

The observations relating to iodine deficiency in pregnancy are firstly those concerned with maternal thyroid function and maternal goiter. Maternal urinary iodine (UI) excretion is the usual method of assessing iodine status in the population at risk or the individual, and is discussed below. Neonatal indicators of maternal iodine deficiency are goiter and neurointellectual impairment. 

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