TSH neonatal como marcador del estado de nutrición de yodo. Influencia de la yoduria y la función tiroidea maternas sobre la TSH neonatal / Neonatal TSH as a marker of iodine nutrition status. Effect of maternal ioduria and thyroid function on neonatal TSH

Introducción: La TSH neonatal (TSHn) es un marcador de nutrición de yodo en la población. La OMS relaciona una prevalencia<3% de TSHn>5mUI/L, obtenida a partir de las 72h del nacimiento, con un adecuado estado nutricional de yodo. El objetivo de este estudio es conocer la prevalencia de TSHn>5mUI/L en una población yodosuficiente y su relación con factores maternos, neonatales y obstétricos. Materiales y métodos: Se reclutaron 243 gestantes entre mayo-junio de 2017 en nuestra área sanitaria. Se realizó un cuestionario sobre consumo de yodo y determinación de yoduria, función y autoinmunidad tiroideas en el primer trimestre de gestación. Se analizó la TSHn entre 48-72h del nacimiento, así como otros factores obstétricos y neonatales. Resultados: La TSHn media fue 2,43±1,68mUI/L, con un 7,8% de neonatos con TSHn>5mUI/L. La TSHn más elevada pertenecía a los neonatos de madres con yodurias insuficientes (p=0,021) o con TSH>2,5mUI/L, tanto en autoinmunidad tiroidea negativa (p=0,049) como positiva (p=0,006). La yoduria materna<150μg/L fue un factor de riesgo de TSHn>5mUI/L (3,70 [1,06-14,60], p=0,046), mientras que el peso neonatal ≥2500g fue un factor protector (0,14 [0,02-1,00], p=0,038). Conclusiones: La prevalencia de TSHn>5mUI/L en nuestra área sanitaria fue elevada, según las recomendaciones de la OMS. Se asoció el déficit de yodo materno con mayor riesgo de TSHn>5mUI/L. Dado que en la actualidad la determinación de la TSHn se realiza antes de las 72h del nacimiento, precisamos de nuevos puntos de corte para continuar empleando la TSHn como marcador de nutrición de yodo. (AU)

Introduction: Neonatal thyroid stimulating hormone (nTSH) is a marker of iodine nutrition status in the population. The WHO considers a prevalence of less than 3% of nTSH levels greater than 5mIU/L in samples obtained within 72h from birth indicative of iodine sufficiency. The aim of this study was to determine the prevalence of nTSH levels greater than 5mIU/L in an iodine-sufficient population and its association with maternal, neonatal and obstetric factors. Materials and methods: A total of 243 pregnant women were recruited between May and June 2017 in our health area. A questionnaire of iodine intake was administered, in addition to determination of ioduria, thyroid function and autoimmunity in the first trimester of gestation. We analysed nTSH levels in samples collected between 48 and 72h post birth and other obstetric and neonatal factors. Results: The mean nTSH level (standard deviation) was 2.43 (1.68mIU/L), with 7.8% of neonates having levels greater than 5mIU/L. The highest nTSH levels corresponded to neonates of mothers with insufficient ioduria (p=.021) or TSH levels greater than 2.5mIU/L, in both the case of negative (p=0.049) and positive (p=0.006) thyroid autoimmunity results. Maternal ioduria greater than 150μg/L was a risk factor for nTSH levels greater than 5mIU/L (3.70 [1.06–14.60]; p=0.046), while a neonatal weight of 2500g or greater was a protective factor (0.14 [0.02–1.00]; p=0.038). Conclusions: The prevalence of nTSH levels greater than 5mIU/L in our health area was high based on the WHO recommendations. Maternal iodine deficiency was associated with a higher risk of nTSH levels less than 5mIU/L. Given that nTSH is currently measured before 72h post birth, we need new cut-off points to keep on using nTSH as a marker of iodine nutritional status. (AU)

Higher maternal thyroid resistance indices were associated with increased neonatal thyroid-stimulating hormone- analyses based on the Huizhou mother-infant cohort.

Objectives: This study aimed to explore the relationship of maternal thyroid function and thyroid resistance parameters with neonatal thyroid-stimulating hormone (TSH). Methods: This work was a longitudinal study. Singleton pregnant women without a history of thyroid disorders were recruited in their first prenatal visit from October 2018 to June 2020. Maternal thyroid markers including TSH, free triiodothyronine (FT3), free thyroxine (FT4), and neonatal TSH were tested in the clinical laboratory of the hospital by electrochemiluminescence immunoassay. Thyroid resistance indices including Thyroid Feedback Quantile-based Index (TFQI), TSH index (TSHI), and thyrotroph T4 resistance index (TT4RI) were estimated in accordance with maternal FT4 and TSH levels. Multivariable linear and logistic regression was applied to explore the associations of maternal thyroid indices with infantile TSH level. Results: A total of 3,210 mothers and 2,991 newborns with valid TSH data were included for analysis. Multivariable linear regression indicated that maternal thyroid variables were significantly and positively associated with neonatal TSH levels with standardized coefficients of 0.085 for TSH, 0.102 for FT3, 0.100 for FT4, 0.076 for TSHI, 0.087 for TFQI, and 0.089 for TT4RI (all P < 0.001). Compared with the lowest quartile, the highest quartile of TSHI [odds ratio (OR) = 1.590, 95% CI: 0.928-2.724; Ptrend = 0.025], TFQI (OR = 1.746, 95% CI: 1.005-3.034; Ptrend = 0.016), and TT4RI (OR = 1.730, 95% CI: 1.021-2.934; Ptrend = 0.030) were significantly associated with an increased risk of elevated neonatal TSH (>5 mIU/L) in a dose-response manner. Conclusion: The longitudinal data demonstrated that maternal thyroid resistance indices and thyroid hormones in the first half of gestation were positively associated with neonatal TSH levels. The findings offered an additionally practical recommendation to improve the current screening algorithms for congenital hypothyroidism.

Neonatal TSH as a marker of iodine nutrition status. Effect of maternal ioduria and thyroid function on neonatal TSH.

INTRODUCTION: Neonatal thyroid stimulating hormone (nTSH) is a marker of iodine nutrition status in the population. The WHO considers a prevalence of less than 3% of nTSH levels greater than 5 mIU/L in samples obtained within 72h from birth indicative of iodine sufficiency. The aim of this study was to determine the prevalence of nTSH levels greater than 5 mIU/L in an iodine-sufficient population and its association with maternal, neonatal and obstetric factors. MATERIALS AND METHODS: A total of 243 pregnant women were recruited between May and June 2017 in our health area. A questionnaire of iodine intake was administered, in addition to determination of ioduria, thyroid function and autoimmunity in the first trimester of gestation. We analysed nTSH levels in samples collected between 48 and 72h post birth and other obstetric and neonatal factors. RESULTS: The mean nTSH level (standard deviation) was 2.43 (1.68 mIU/L), with 7.8% of neonates having levels greater than 5 mIU/L. The highest nTSH levels corresponded to neonates of mothers with insufficient ioduria (P = 0.021) or TSH levels greater than 2.5 mIU/L, in both the case of negative (P = 0.049) and positive (P = 0.006) thyroid autoimmunity results. Maternal ioduria less than 150 µg/L was a risk factor for nTSH levels greater than 5 mIU/L (3.70 [1.06-14.60]; P = 0.046), while a neonatal weight of 2500 g or greater was a protective factor (0.14 [0.02-1.00]; P = 0.038). CONCLUSIONS: The prevalence of nTSH levels greater than 5 mIU/L in our health area was high based on the WHO recommendations. Maternal iodine deficiency was associated with a higher risk of nTSH levels greater than 5 mIU/L. Given that nTSH is currently measured before 72h post birth, we need new cut-off points to keep on using nTSH as a marker of iodine nutritional status.

Iodine intake monitoring in neonatal population in the Czech Republic: alarming numbers in 2020.

Thanks to comprehensive and long-term preventive programs, the Czech Republic has taken its place among the countries with a resolved iodine deficiency at all population levels since 2004. A sensitive indicator of iodine supply to the population, which can also be used to monitor the efficiency of prophylactic programs, is the TSH assessment in the nationwide neonatal screening of congenital hypothyroidism. Nevertheless, recent results of neonatal TSH show that newborns and pregnant women remain very risky groups and their iodine saturation is borderline. In recent years, the percentage of newborns with TSH 5-15 mIU/l has already risen above the 3% mark, i.e. mild iodine deficiency in major part of the Czech Republic (3.8 % in Bohemia, 2.8% in Moravia in 2019 and 4.7 % in Bohemia, 2.9% in Moravia in 2020). For some smaller areas, the values are even higher, which can be related, for example, to the social patterns of the population. The result may be not only the exclusion of the Czech Republic from the list of countries with resolved iodine deficiency, but especially adverse consequences for the cognitive development of the future generation. Therefore, it is essential to intensify nation-wide intervention among both the professional and general public. In this regard, adherence to the supplementation of pregnant and breastfeeding women is crucial with 150-200 μg of iodide in addition to nutritional iodine intake.

Higher frequency of Congenital Hypothyroidism among Newborns, District Dera Ghazi Khan-Punjab, Pakistan: A case control study.

OBJECTIVES: The study objective was to establish serum TSH cut off value for diagnosis of new case of congenital hypothyroidism and to estimate frequency of Congenital Neonatal Hypothyroidism. METHODS: A case control study was conducted at DHQ Teaching Hospital of DG Khan Medical College, Dera Ghazi Khan during 2020 to establish reference values of TSH and T4 for study population. Sample size was calculated by classical sample size calculation formula Cochran WG 1977 sampling technique. A group of 30 neonates of normal, healthy, euthyroid mothers was taken as Neonatal Control Group to estimate levels of TSH and total T4 in normal neonates. Neonatal Study Group was neonates of hypothyroid mothers (n=75). Simple random sampling technique was applied. RESULTS: Mean (mean ± SD) Serum TSH levels of Neonatal Control Group were found to be 3.58 ± 03.09 mIU/l. Mean Serum TSH levels among Neonatal Study Group were found to be 6.88 ±12.95 mIU/l and serum total T4 were found to be 16.78 ± 6.96ug/dl on 3-7 days of life. Serum total T4 (mean ± SD) levels of Neonatal Control Group were 9.73 ± 03.39 ug/dl. Neonatal serum TSH more than 15mIU/l was taken as cut off value to diagnose a case of CNH. So, frequency of CNH was 8% among neonates of study group. CONCLUSIONS: The TSH cut off value of >15mIU/l was established for case detection of CNH. Our findings of CNH in district Dera Ghazi Khan (8%) are the highest frequency of CNH reported so far in Pakistan.

The role of placental iodine storage in the neonatal thyroid stimulating hormone surge: iodine as a driving force to adapt the terrestrial life.

PURPOSE: Iodine plays a pivotal role in adaptation during the transition from intrauterine to extrauterine life. Although it is well known that the placenta plays a role in iodine storage, a relationship between the neonatal thyroid stimulating hormone (TSH) peak and placental iodine concentration has not been established. This study focuses on the role of placental iodine concentration in the TSH surge after delivery. MATERIALS AND METHODS: This study included 42 mothers and their newborns, none of whom had perinatal risk factors. The following samples were collected to analyze iodine: placental tissue, amniotic fluid (AF), and 24-h maternal urine. Blood was drawn from the umbilical cord (uc), newborns (at the 1st-24th hours), and mothers (at 1st hour) to analyze the following hormones: TSH, freeT4/T3(fT4/fT3), human chorionic gonadotrophin (hCG), prolactin (PRL), follicle stimulating hormone (FSH), luteinizing hormone (LH), and cortisol. RESULTS: The mean iodine levels of placental tissue, AF, and 24-h maternal urine were as follows: 29.06 ± 45.88 µg/kg, 182.80 ± 446.51 µg/L, and 498.35 ± 708.34 µg/L, respectively. The mean TSH and hCG values were 32.41 ± 13.96mIU/ml and 30.66 ± 18.55mIU/ml, respectively, at the 1st hour. Placental iodine had strong, very strong, and weak negative correlations with TSH, hCG, and PRL, respectively (rTSH = - 0.763, p < 0.001;rHCG = - 0.919, p < 0.001; rPRL = - 0.312, p = 0.044). CONCLUSION: This study showed that the placental iodine level was inversely correlated with neonatal TSH, hCG, and PRL. It indicates that placental iodine concentration is an efficient driving force shaping the dynamic pattern of the neonatal TSH peak in addition to hCG and PRL surges, which reflects the adaptive effort in the transition from intrauterine to extrauterine life.

Congenital hypothyroidism in preterm infants: a 3- to 8-year longitudinal study in southern Thailand.

Background Preterm infants are at high risk of developing congenital hypothyroidism (CH) due to the immaturity of the hypothalamic-pituitary-thyroid (HPT) axis, loss of iodine supply from the mother and preterm health problems. Objectives To study the incidence and etiologies of CH in preterm infants who were born or admitted in our institute during 2010-2015. Methods The medical records of preterm infants diagnosed with CH as defined by the thyroid-stimulating hormone (TSH) level at the time of the first or second screening >10 mU/L and/or free T4 < 1.00 ng/dL were reviewed. Results Of 2777 preterm infants, 73 cases (2.6%) were diagnosed as CH. The average TSH levels at the first and second screenings were 20.85 and 15.42 mU/L, respectively. The patients were treated with thyroxine at an average initial dosage of 15 µg/kg/day. At 2-3 years of age, after thyroxine discontinuation for 6-10 weeks and regular thyroid function tests for 2 years, 58 patients (79.5%) were diagnosed as having transient CH and 15 patients (20.5%) were diagnosed as having permanent CH. We found no clinical or laboratory parameters in the neonatal period that could differentiate permanent from transient CH. Thyroid scintigraphy (99 m pertechnetate) revealed two patients (13.3%) with ectopic thyroid, one with thyroid hypoplasia (6.7%), eight with normal thyroid (53.3%) and four with enlarged thyroid (26.7%). Conclusions CH was common in preterm infants with an estimated incidence of 2.6%. Thyroxine should be given to preterm infants with higher initial values of TSH >10 mU/L in order to prevent delayed treatment of permanent CH that could be confirmed later.

The etiologies and incidences of congenital hypothyroidism before and after neonatal TSH screening program implementation: a study in southern Thailand.

BACKGROUND: Congenital hypothyroidism (CH) is one of the common causes of intellectual disability which can be prevented by early detection of an elevated thyroid stimulating hormone (TSH) level in the newborn and by treatment with thyroxine. In Thailand, neonatal TSH screening was implemented nationwide in 2005. The objective of the study was to determine the etiologies and the estimated incidences of CH in southern Thailand before and after the implementation of a neonatal TSH screening program in 2005. METHODS: The medical records of pediatric patients who were diagnosed with primary CH at Songklanagarind Hospital during 1995-2013 were retrospectively reviewed. The study was divided into two time periods: study period 1 (SP1) (1995-2004) and study period 2 (SP2) (2005-2013), the time before and after TSH program implementation. RESULTS: The most common form of CH during SP1 was overt permanent CH (66%), mostly caused by athyreosis or ectopic thyroid. In SP2, the most common form of CH was mild permanent CH (39%) (mostly due to dyshormonogenesis), followed by overt CH (32%) and transient CH (29%). The overall annual estimated incidence of CH per 10,000 live births in Songkhla Province was 1.69 (1:5021) in SP1, increasing to 4.77 (1:2238) in SP2; in all 14 provinces in southern Thailand, the estimated incidence was 1.24 (1:8094) in SP1 and 2.33 (1:4274) in SP2. CONCLUSIONS: Neonatal TSH screening has a significant impact on the increased detection of the mild form of permanent and transient CH cases, which may be important for the prevention of brain damage from less severe CH although this remains to be documented.

Iodine supplementation during pregnancy of hypothyroid women treated with L-thyroxine neither influences neonatal TSH nor prevents decrease in maternal free thyroid hormone concentrations in second and third trimesters.

INTRODUCTION: Pregnant women require about 250 µg of iodine daily. Hypothyroid women treated with L-thyroxine do not utilise iodine, and metabolism of L-thyroxine tablets is an additional source of iodine for their foetuses. The aim of the study was to evaluate the influence of iodine supplementation in hypothyroid pregnant women treated with L-thyroxine on neonate TSH concentration and maternal thyroid parameters. MATERIAL AND METHODS: Ninety-two pregnant women with primary hypothyroidism on adequate thyroid hormone replacement were voluntarily divided into two groups: "thyroxine" (n = 38) treated with L-thyroxine only, and "thyroxine + iodine" (n = 54) treated additionally with 150 µg/day of iodine since 10th gestational week. Primary outcomes were the maternal thyroid function tests (TSH, fT4, fT3) and neonatal TSH concentrations at the 3-4th day of life. Urinary iodine concentration was measured at first and third trimester to compare iodine status in both groups. RESULTS: Iodine supplementation significantly increased median urinary ioduria in the third trimester (from 95.15 µg/L to 151.50 µg/L), but did not prevent the decrease of maternal fT4 and fT3 concentrations in the second and third trimester. Median neonate TSH concentration in both groups was within normal range, but was 33% higher in the "thyroxine + iodine" than in the "thyroxine" group (1.91 mU/L vs. 1.34 mU/L). Moreover, 8.77% of newborns in the "thyroxine + iodine" group had TSH > 5 mIU/L. CONCLUSIONS: We did not find evidence for a positive influence of iodine supplementation on thyroid function of either hypothyroid pregnant women sufficiently treated with L-thyroxine or their neonates. (Endokrynol Pol 2016; 67 (4): 367-374).

Supervisión del déficit de yodo en Salta Capital / Surveillance of iodine deficiency in Salta Capital

El déficit de yodo (IDD) es un problema de Salud Pública que afecta a millones de personas en todo el mundo causando alteraciones en la neuromaduración que pueden ser evitados si se realiza una yodoprofilaxis adecuada. Objetivo: Realizar un monitoreo de IDD en la localidad de Salta Capital, por su ubicación geográfica y hábitos alimentarios con posible consumo regional de sal no iodada. Material y métodos: En 442 escolares (221 mujeres) de 5 a 14 años de edad, se evaluaron: peso, SDS talla y, SDS BMI. Se realizó la palpación tiroidea y el volumen glandular fue clasificado según los criterios de la OMS. En 97 niños se determinó la yoduria en muestras casuales de orina por el método de Sandell y Kolthof modificado. Se analizó la distribución de los niveles de TSH de la pesquisa neonatal (IFMA-DELFIA) realizada en la región de los 18 meses previos al estudio Se aplicaron los criterios de suficiencia iodada establecidos por la OMS/ ICCDD Resultados: La prevalencia de bocio fue de 6.3 %. Los niveles de yoduria fueron: mediana de 127.5 ug/l con 20 % < 50 ug/l. Sólo el 1.6 % de las muestras de TSH neonatal fueron > 5 uU/ml. Cuando se aplicaron los criterios de la OMS la prevalencia de bocio superaba levemente lo esperado para una zona suficiente y los niveles de ioduria correspondían con un aporte iodado adecuado pero marginal en su distribución. La distribución de TSH fue la esperada para una zona suficiente. Conclusión: Si bien el aumento de la prevalencia de bocio podría explicarse por factores ambientales la distribución marginal de la ioduria señala un aporte de yodo suficiente pero con necesidad de supervisión estrecha.

The iodide deficit disorder (IDD) is a worldwide Public Health problem that affects more than a million subjects causing neuromadurative disorders that could be avoided with adequate iodide supply. Objective: To monitor IDD in Salta Capital, due to its geographic location and possible utilization of non iodated salt. Population and methods:. SDSHeight , SDS BMI and weight were assessed in 442 scholars (221 girls) aged 5 to 14. Thyroid volume was evaluated and classified according to WHO criteria. In 97 children iodide urinary concentration was measured in casual urine samples by the modified Sandell and Kolthof method.TSH level's distribution of the neonatal screening performed in the region 18 months prior to this study (n 310) was evaluated. Criteria suggested by WHO to indicate iodide deficiency were applied. Results: Goitre prevalence was 6.3%, Iodide urine median levels were 127.5 ug/l with 20% < 50 ug/l. Only 1.6% of the 310 TSH samples were > 5 μU/ml. Applying WHO criteria goiter prevalence was higher that expected for a iodide sufficient area and urine iodide content was normal but marginal in its distribution. Neonatal TSH levels were the expected for a sufficient area. Conclusion: Although high goiter prevalence could be explained by environmental factors the distribut-ion of urinary iodide points out an adequate but marginal iodide supply underscoring the need of close monitoring.

Pesquisa neonatal de hipotiroidismo congénito: supervisión del déficit de yodo en la provincia de Misiones / Screening neonatal for congenital hypothyroidism: surveillance of iodine deficiency in Misiones

El déficit de yodo (IDD) es un problema de la Salud Pública que afecta a millones de personas en todo el mundo y es causante de alteraciones en la neuromaduración que pueden ser evitados si se realiza una yodoprofilaxis adecuada. Objetivo: Realizar un monitoreo de IDD en la localidad de Wanda, provincia de Misiones, por su ubicación geográfica y hábitos alimentarios con posible consumo regional de sal no iodada. Se estudiaron en 502 escolares de 5 a 14 años de vida , se evaluaron: peso, talla , BMI y palpación tiroidea. En 114 de ellos se determinó la yoduria en muestras casuales de orina. Se analizaron los niveles de TSH de la pesquisa neonatal de los 18 meses previos al estudio, realizados por métodos sensibles (IFMA-DELFIA). Se aplicaron los criterios de suficiencia establecidos por la OMS/ ICCDD. Resultados: La prevalencia de bocio en la región fue de 6.2 %. Los niveles de yoduria tuvieron una mediana de 239 ug/l. El valor de TSH neonatal mediano fue 1.25 uU/ml. Sólo el 1.4 % de las muestras estaban por encima de 5 uU/ml . Cuando se aplicaron los criterios de la OMS pudo observarse que la prevalencia de bocio superaba levemente lo esperado para una zona suficiente, pero no así los niveles de ioduria ni la distribución de TSH neonatal. Conclusión: El aporte iodado de la región evaluada es suficiente como lo demuestran la ioduria y los niveles de TSH neonatal. La presencia de bociógenos como la mandioca en la dieta puede explicar el leve aumento en la prevalencia de bocio. La utilización de la pesquisa neonatal de hipotiroidismo congénito en la supervisión de la deficiencia de yodo añade un beneficio al objetivo primario que es la prevención del retraso mental.

O b j e c t i v e : To estimate the adequacy of iodide intake in Wanda Misiones through the conventional parameters of ioduria and goiter prevalence in scholars as well as with the distribution of TSH neonatal levels as performed for the hypothyroidism screening program in newborns. Population and methods: Height , and BMI and weight were assessed in 502 scholars aged 5 to 14 and expressed as SDS. In 419 of them (215 female) thyro i d volume was evaluated and classified according to WHO (9). In 114 children iodide urinary concentration was measured in casual urine samples by Sandell y Kolthof method modified by Pino (17). Neonatal screening program for congenital hypothyroidism is carried out in the region measuring TSH in filter paper samples with IFMA DELFIA. Since 2000 7.102 newborn have been screened. TSH level's distribution of the 18 months prior to this study (n 267) were evaluated. Criteria suggested by WHO to indicate iodide deficiency were applied. Results: Height, weight and BMI were normal for the chronological age according to Argentinean population parameters. Goitre prevalence was 6.2 % (7.3 % in girls and 5.3 % in boys), higher that expected for a iodide sufficient area. Iodide urine median levels were 239 ug/l with a distribution that excluded iodide deficiency. Neonatal screening program detected 5 congenital hypothyroid children out of the 7102 newborn studied. All of them were early and adequately treated. Only 1.4 % of the 267 samples were > 5 µU/ml, excluding iodide deficiency. Conclusion: Iodide intake in Wanda, Misiones, is adequate as shown by the findings of iodide urine concentration and TSH neonatal levels. A higher prevalence of goitre than expected for this situation, could be explained by dietary intake of goitrogen food as mandioca. Congenital hypothyroidism screening program in this region was extremely effective. The possibility of using its results for iodide intake supervision is an additional benefit to the one of early prevention of mental retardation.

Alterations of the TSH Levels in the Breast Feeding Newborn Infants after the Mother's Eating Brown Seaweed Soup / 대한주산의학회잡지

PURPOSE: After delivery, eating brown seaweed soup is a typical Korean tranditional habit. But, excessive intake of iodine transiently inhibits biosynthesis and secretion of thyroid hormones if a certain threshold of iodine is reached in the serum. The aim of our study was to demonstrate whether the observed the elevations of TSH level in the breast fed neonatal infants was caused by mother's eating brown seaweed soup or not. METHODS: We performed neonatal TSH test by enzyme linked immunosorbent assay(FRELISA Screenig TSH) and cheked TSH level for 178 newborns with a appropriate gestational age. We divided the study subject into 3 groups, the group used breast feeding, mother had taken brown seaweed soup and blood sampled at 6th day after birth was categorized Group A, formular feeding, blood sampled at the 4th days after birth was categorized Group B, breast feeding and had taken brown seaweed soup and blood sampled at the 19th day after birth was categorized Group C. RESULTS: 1) The mean TSH level was 1.5+/-1.3 uU/ml in Group A, 3.3+/-2.5uU/ml in Group B, 1.7+/-l.3uU/ml in Group C(Group A vs Group B: p<0.05, Group A vs Group C: p<0.05). 2) There was no statistical significances between the TSH levels and the amount of brown seaweed soup which mother had one day, the duration which mother had brown seaweed soup and duration of breast feeding. CONCLUSIONS: Mother had taken brown seaweed soup about 3 times a day in korea at present days, There was no significant changes of TSH levels in the beast fed newborn infants after the korean mother had taken brown seaweed soup.