Update of newborn screening and therapy for congenital hypothyroidism

Provider variability in the initial diagnosis and treatment of congenital hypothyroidism

BACKGROUND

Early diagnosis and expeditious treatment of newborns with congenital hypothyroidism (CH) is necessary to avoid mental retardation.

METHODS

A survey of 44 practitioners in the southern US was conducted to better understand common practices regarding neonatal CH and the findings were compared with current guidelines in the US and Europe.

RESULTS

Responses indicated some consensus that 10-15 μg of thyroid hormone/kg/day was the appropriate dosage. However, despite guidelines advocating their use, practitioners reported that they did not commonly use imaging or laboratory tests, though experienced providers apparently used them more often.

CONCLUSIONS

Together, these results show moderate adherence to published guidelines for treating and diagnosing CH. Further research is needed to determine why providers deviate from these guidelines and to generalize these results to other populations.

Hypothyroidism in Pediatric Population - Bosnian and Herzegovinian Situation

Introduction:

Thyroid gland diseases in children are in second place by frequency among all endocrine disorders. When interpreting the results of the thyroid function assessment it should be taken into account the significant differences in the concentrations of TSH, thyroid hormones, thyroid binding proteins and calcitonin among children of different ages.

Goal:

To present the age and sex structure of the patients diagnosed with hypothyroidism, evaluate diagnostic methods for making diagnosis, evaluation of etiology of hypothyroidism, with special review of the therapeutic modality.

Patients and methods:

The study have retrospective character and includes all patients who have the diagnosis of hypothyroidism, but at the moment of data collection were aged 0-18 years.

Results:

Distribution of patients on the basis of gender, revealed more significant representation of female (65.93%), and without significant difference in the presence of the disease in relation to age (p>0.05). Physical examination of the struma was not verified in the majority of cases (74; 81.32%, p<0.05) suffering from hypothyroidism. Ultrasound review in 22 (50%) cases confirmed the struma. Ultrasound findings in most cases 14 (31.81%) demonstrated diffuse struma and Hashimoto thyroiditis together. In relation to the etiology of hypothyroidism most patients belong to a group where hypothyroidism is associated with other diseases and conditions (27; 29.67%), but the least with congenital hypothyroidism with 18 (19.78%) cases. The average dose of L-thyroxine in the age of 0-1 months was 50 mg, 1 month–10 years 37.5 mcg, and the group of patients over 10 years 65 mcg.

Conclusion:

Congenital hypothyroidism has about one-fifth of patients. Physical examination revealed in about one fifth of patients the struma of the thyroid gland; TSH levels is critical for the diagnosis and correction of therapy in pediatric patients with hypothyroidism. Congenital hypothyroidism is diagnosed on average at the age of 12 days, which is optimal for period for therapeutic response; Substitution treatment is carried out with L-thyroxine which is relatively reduced in doses from neonatal age onwards.

Ethnicity and incidence of congenital hypothyroidism in the capital of Macedonia

BACKGROUND

Congenital hypothyroidism (CH) is a common and preventable cause of intellectual disability for which early diagnosis is difficult without newborn screening. Genetic and environmental factors, race, ethnicity, sex, and pregnancy outcomes were noted as risk factors. In the study we aimed to determine the incidence of CH among different ethnic groups in the capital of Macedoina - a multiethnic city.

METHODS

A 14-year retrospective cohort analysis was performed on 121,507 newborns in the capital of Macedonia, Skopje, screened for whole-blood thyroid-stimulating hormone (TSH), in dry blood spots collected 48-72 h after birth, during the period 2002-2015. A TSH value of 15 mIU/L was used as cutoff point until 2010 and 10 mIU/L thereafter.

RESULTS

Primary CH was detected in 46 newborns (female to male ratio 1.3) with overall incidence of 3.8/10,000 (1/2641). The incidence of primary CH was significantly increased after lowering the TSH cutoff value (p=0.038), primarily due to detected neonates with transient CH for this period. Ethnic differences in the incidence of primary CH were detected. CH incidence among Roma neonates (6.7/10,000) was significantly higher (p<0.05) than the incidence detected in Macedonians (3.9/10,000) or Albanians (3.7/10,000).

CONCLUSIONS

Increased incidence of CH in Roma newborns was detected as compared to other ethnicities in the capital of Macedonia. Further analysis of factors in direct interrelationship with the increased CH incidence in Roma newborns, as well as elucidation of impact of the CH incidence in this ethnicity on the overall incidence in Skopje, is warranted.

Characterization of Thyroid Abnormalities in a Large Cohort of Children with Down Syndrome

BACKGROUND/AIMS

Thyroid disease is a common comorbidity in individuals with Down syndrome (DS), but historical studies have multiple limitations. We assessed thyroid abnormalities in a large cohort of children with DS.

METHODS

Retrospective records review from a single institution. Calculated prevalence of common thyroid abnormalities and associations with common comorbidities.

RESULTS

Among 508 patients, 120 (24%) had a thyroid-related diagnosis, the majority having elevated thyrotropin treated with levothyroxine. A Kaplan-Meier estimate projects that 50% have thyroid disorder by adulthood, with 20% of hypothyroidism diagnosed before the age of 6 months. When tested, approximately 50% had positive antithyroid antibodies, though this rate was 100% in overt hypothyroidism. There was no association between congenital or acquired hypothyroidism and common comorbidities.

CONCLUSION

Thyroid disease in DS is more common and occurs earlier than in the general population, and is often transient. Thyroid disease is unrelated to gender, obesity, or other comorbidities. Apart from overt hypothyroidism, much of hypothyroidism in DS appears unrelated to autoimmunity; we recommend checking of antithyroid antibodies only in select cases. An additional screen for thyroid disease between the newborn screen and the 6-month well-child visit will detect early cases of hypothyroidism who passed their newborn screen.
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2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum

BACKGROUND

Thyroid disease in pregnancy is a common clinical problem. Since the guidelines for the management of these disorders by the American Thyroid Association (ATA) were first published in 2011, significant clinical and scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid disease in women during pregnancy, preconception, and the postpartum period.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations. The guideline task force had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid disease in pregnancy include recommendations regarding the interpretation of thyroid function tests in pregnancy, iodine nutrition, thyroid autoantibodies and pregnancy complications, thyroid considerations in infertile women, hypothyroidism in pregnancy, thyrotoxicosis in pregnancy, thyroid nodules and cancer in pregnant women, fetal and neonatal considerations, thyroid disease and lactation, screening for thyroid dysfunction in pregnancy, and directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid disease in pregnant and postpartum women. While all care must be individualized, such recommendations provide, in our opinion, optimal care paradigms for patients with these disorders.

Evaluation of the revised New Zealand national newborn screening protocol for congenital hypothyroidism

OBJECTIVE

The aim of this study was to assess the performance of the revised New Zealand (NZ) newborn screening TSH cut-offs for congenital hypothyroidism (CHT).

METHODS

Screening data over 24 months were obtained from the NZ newborn metabolic screening programme, which utilizes a 2-tier system of direct clinical referral for infants with markedly elevated TSH, and second samples from those with mild TSH elevation. We evaluated the impact of a reduced TSH threshold (50 to 30 mIU/l blood) for direct notification and a lower cut-off (15 to 8 mIU/l blood) applied to second samples and babies older than 14 days.

RESULTS

In 2013 and 2014, 117 528 infants underwent newborn screening for CHT. Fifty-two CHT cases were identified by screening (47 general newborn population, five repeat testing in low-birth-weight infants) and one case was missed. Thirty-two infants with screening TSH ≥30 mIU/l were directly referred at a median of 9 days (5-14) and 15 with TSH 15-29 mIU/l were referred after a second sample at a median of 20 days (9-52, P < 0·001). All directly referred infants were confirmed as CHT cases with no earlier referrals as a result of the reduced threshold. The lower TSH cut-off applied to second samples lead to the identification of six extra cases of CHT (15% increase) from seven extra clinical referrals.

CONCLUSIONS

The NZ screening programme achieved a 15% increase in CHT case detection for minimal increase in workload or anxiety for families of healthy infants. A further decrease in the threshold for direct referral may allow earlier diagnoses.

Exome sequencing identifies SLC26A4, GJB2, SCARB2 and DUOX2 mutations in 2 siblings with Pendred syndrome in a Malaysian family

BACKGROUND

Pendred syndrome (PDS, MIM #274600) is an autosomal recessive disorder characterized by congenital sensorineural hearing loss and goiter. In this study, we describing the possible PDS causal mutations in a Malaysian family with 2 daughters diagnosed with bilateral hearing loss and hypothyroidism.

METHODS AND RESULTS

Whole exome sequencing was performed on 2 sisters with PDS and their unaffected parents. Our results showed that both sisters inherited monoallelic mutations in the 2 known PDS genes, SLC26A4 (ENST00000265715:c.1343C > T, p.Ser448Leu) and GJB2 (ENST00000382844:c.368C > A, p.Thr123Asn) from their father, as well as another deafness-related gene, SCARB2 (ENST00000264896:c.914C > T, p.Thr305Met) from their mother. We postulated that these three heterozygous mutations in combination may be causative to deafness, and warrants further investigation. Furthermore, we also identified a compound heterozygosity involving the DUOX2 gene (ENST00000603300:c.1588A > T:p.Lys530* and c.3329G > A:p.Arg1110Gln) in both sisters which are inherited from both parents and may be correlated with early onset of goiter. All the candidate mutations were predicted deleterious by in silico tools.

CONCLUSIONS

In summary, we proposed that PDS in this family could be a polygenic disorder which possibly arises from a combination of heterozygous mutations in SLC26A4, GJB2 and SCARB2 which associated with deafness, as well as compound heterozygous DUOX2 mutations which associated with thyroid dysfunction.

Neurological Complications of Endocrine Disease

The endocrine system is a complex group of organs and glands that relates to multiple other organs and systems in the body with the ultimate goal of maintaining homeostasis. This complex network functions through hormones excreted by several glands and released in the blood, targeting different body tissues and modulating their function. Any primary disorders affecting the endocrine glands and altering the amount of hormones synthesized and released will lead to disruption in the functions of multiple organs. The central nervous system of a developing child is particularly sensitive to endocrine disorders. A variety of neurological manifestations have been described as features of several endocrine diseases in childhood. Their knowledge may contribute to an early diagnosis of a particular endocrine condition, especially when more typical features are not present yet. In this article, we discuss specific neurological manifestations found in various endocrine disorders in children.

Perchlorate and Diet: Human Exposures, Risks, and Mitigation Strategies

Perchlorate is an endocrine-disrupting chemical that interferes with the normal functioning of the thyroid gland. Maternal thyroid dysfunction during gestation may alter fetal brain development. Perchlorate contamination is widespread: it is present in the body of all Americans tested and the majority of foods tested. The main sources of food contamination appear to be hypochlorite bleach, a disinfectant and sanitizer, that when poorly managed quickly degrades to perchlorate and perchlorate-laden plastic food packaging for dry food or localized contamination from manufacturing or processing of the chemical. Eliminating perchlorate from food packaging and improving bleach management, such as reducing concentration and storage time and temperature, would result in reduced perchlorate contamination of food and water.

Congenital Hypothyroidism: Role of Nuclear Medicine

Thyroid scintigraphy holds a key place in the etiologic workup of neonatal hypothyroidism. Routine screening for this disorder in maternity hospitals in industrialized countries, for nearly 40 years, has permitted early treatment and thereby helped to prevent its physical and mental complications. Neonatal hypothyroidism affects approximately 1 in 3000 births. The most common causes are abnormal thyroid gland development and defective hormone synthesis by an eutopic thyroid gland. The incidence of the latter has risen in recent years, for reasons that remain unclear. A thorough etiologic workup helps to determine the disease type. Current guidelines recommend thyroid imaging by means of ultrasound and scintigraphy. Ultrasound should be done by a practitioner trained to examine the cervical region of newborns, as the thyroid is very small and must be distinguished from the particular aspect of the "thyroid empty lodge." Ultrasound lacks sensitivity for detecting small ectopic glands but is the gold standard for measuring thyroid dimensions. Scintigraphy provides an etiologic diagnosis in most cases. The two isotopes used in this setting are technetium-99m and iodine-123. The latter isotope gives more contrast and allows the perchlorate discharge test to be performed to detect abnormal iodide organification in the neonate with an eutopic thyroid. If scintigraphy cannot be performed during the neonatal period, a postponed procedure can be achieved after 3 years of age. Close cooperation between the nuclear medicine physician and the pediatric endocrinologist is crucial for timely and optimized scintigraphy.

National survey on concepts for congenital hypothyroidism screening in neonatal intensive care units in Japan

BACKGROUND

Recently, a revised version of the Guidelines for Mass Screening of Congenital Hypothyroidism (CH) was published in Japan, but it is not known whether the guidelines are used routinely in neonatal intensive care units (NICU).

METHODS

To clarify the current status and issues of newborn screening (NBS) for CH in Japanese NICU, we sent a questionnaire by mail or email to neonatologists responsible for 100 tertiary NICU in Japan, and analyzed their responses.

RESULTS

The response rate was 92% (92/100). Among respondents, 65% (59/91) performed thyroid function testing separately from NBS for CH. Within this group, 63% (37/59) applied criteria, mostly for very low-birthweight (VLBW) infants (25/37). Only 29% of respondents (26/90), however, used criteria to select VLBW infants for treatment. Furthermore, criteria differed in each NICU. Fifty-seven percent of respondents (50/87) reported issues regarding NBS for CH in NICU, which fell into three main areas: establishment of a clear method for the management of VLBW infants; necessity of simultaneous measurement of thyroid-stimulating hormone and free thyroxine; and overlapping blood collection for NBS and thyroid function tests.

CONCLUSIONS

Two-thirds of tertiary NICU performed thyroid function testing separately from NBS for CH. Approximately 60% of neonatologists responded that current NBS for CH had ongoing issues. Further research is needed to establish the optimal NBS protocol for CH in NICU in Japan.

Thyroid function testing in neonates born to women with hypothyroidism

Our aim was to assess the utility of serum thyroxine and thyroid stimulating hormone performed at 10-14 days of life in diagnosing congenital hypothyroidism (CH) in babies born to mothers with hypothyroidism. This was a retrospective study of all babies born in a tertiary referral centre for neonatology over a 12-month period. Infants who had thyroid function testing (TFT) checked at 10-14 days of life because of maternal hypothyroidism during the period of study were included. The results of the newborn bloodspot and day 10-14 TFT were recorded along with whether or not patients were subsequently treated. Of the 319 patients included in the study, only two patients were found to have CH and in both cases the newborn blood spot had been abnormal.

CONCLUSION

No extra cases of CH were detected from the thyroid test at 10-14 days and this practice should be discontinued due to the robust nature of existing newborn screening programmes. What is Known: • Congenital hypothyroidism(CH) is the commonest preventable cause of childhood intellectual impairment. • Family history of hypothyroidism has been implicated as a risk factor for CH. • CH has formed part of newborn screening since the 1970s. What is New: • There is no research recommending thyroid function testing at 10-14 days of life to detect CH in neonates born to mothers with hypothyroidism. • Thyroid function testing at 10-14 days of life does not improve diagnostic yield for CH in babies born to mothers with hypothyroidism. • Newborn blood spot remains the mainstay for accurate and timely diagnosis of CH.

Translating sickle cell guidelines into practice for primary care providers with Project ECHO

BACKGROUND

Approximately 100,000 persons with sickle cell disease (SCD) live in the United States, including 15,000 in the Midwest. Unfortunately, many patients experience poor health outcomes due to limited access to primary care providers (PCPs) who are prepared to deliver evidence-based SCD care. Sickle Treatment and Outcomes Research in the Midwest (STORM) is a regional network established to improve care and outcomes for individuals with SCD living in Indiana, Illinois, Michigan, Minnesota, Ohio, and Wisconsin.

METHODS

STORM investigators hypothesized that Project ECHO^® methodology could be replicated to create a low-cost, high-impact intervention to train PCPs in evidence-based care for pediatric and young adult patients with SCD in the Midwest, called STORM TeleECHO. This approach utilizes video technology for monthly telementoring clinics consisting of didactic and case-based presentations focused on the National Heart, Lung and Blood Institute (NHLBI) evidence-based guidelines for SCD.

RESULTS

Network leads in each of the STORM states assisted with developing the curriculum and are recruiting providers for monthly clinics. To assess STORM TeleECHO feasibility and acceptability, monthly attendance and satisfaction data are collected. Changes in self-reported knowledge, comfort, and practice patterns will be compared with pre-participation, and 6 and 12 months after participation.

CONCLUSIONS

STORM TeleECHO has the potential to increase implementation of the NHLBI evidence-based guidelines, especially increased use of hydroxyurea, resulting in improvements in the quality of care and outcomes for children and young adults with SCD. This model could be replicated in other pediatric chronic illness conditions to improve PCP knowledge and confidence in delivering evidence-based care.

Feasibility of an Early Discontinuation of Thyroid Hormone Treatment in Very-Low-Birth-Weight Infants at Risk for Transient or Permanent Congenital Hypothyroidism

BACKGROUND/AIMS

This prospective study was conducted to investigate the feasibility of an early discontinuation of thyroid hormone treatment in very-low-birth-weight (VLBW) infants with congenital hypothyroidism (CH).

METHODS

We enrolled VLBW infants between January 2011 and December 2012. The infants were divided into the hypothyroid and normal thyroid function groups according to the results of a thyroid function test. We performed an early off-therapy trial at 24 months of age.

RESULTS

Of the 182 VLBW infants enrolled, 15 were lost to follow-up and 167 were finally enrolled. In total, 24 infants (14.4%) were assigned to the hypothyroid function group and were treated with thyroid hormone. Younger gestational age and a lower birth weight were associated with hypothyroid function. In the hypothyroid function group, hypothyroidism (HT) and hyperthyrotropinemia (HTT) were observed in 13 and 11 infants, respectively. There were no differences in the clinical characteristics between the HT and HTT groups. Overall, 24 infants discontinued thyroxine medication at 24 months of age after normal results had been confirmed by radiologic work-ups, including thyroid ultrasonography and technetium-99m scans. All infants were successfully weaned off thyroxine and maintained euthyroid function.

CONCLUSION

Early discontinuation of thyroid hormone replacement therapy is possible in the majority of VLBW infants with CH.

Congenital hypothyroidism with delayed TSH elevation in low-birth-weight infants: incidence, diagnosis and management

OBJECTIVE

To evaluate the incidence of congenital hypothyroidism (CH) with delayed TSH elevation among low-birth-weight (LBW) newborns in North-Eastern Italy and to verify if they need a second or third screening.

DESIGN

Analysis of clinical and biochemical data of newborns affected by CH with delayed TSH elevation identified by neonatal screening.

METHODS

Data of all newborns with birth weight (BW) <2500 g and evidence of delayed TSH elevation at newborn screening were collected between 2011 and 2014. Confirmatory tests were based on serum TSH and FT4 levels. All their clinical signs at diagnosis were reported.

RESULTS

57.5% of LBW newborns with delayed TSH increase at neonatal screening presented a CH with delayed TSH elevation and began a treatment with l-thyroxine. The incidence of this condition in North-Eastern Italy is therefore 1:908. The remaining infants presented a subclinical hypothyroidism (21.25%) or a complete normal serum thyroid function (21.25%). These data could be drawn only from a retesting strategy of neonatal screening.

CONCLUSIONS

Our report describes the incidence of CH with delayed TSH rise in North-Eastern Italy and differentiates this clinical condition from other thyroid dysfunctions of preterm or LBW newborns. The second-screening strategy for CH in neonates with BW < 2500 g proved useful in detecting newborns who otherwise would not be identified at the first screening.

Characteristics of Delayed Thyroid Stimulating Hormone Elevation in Neonatal Intensive Care Unit Newborns

OBJECTIVES

To elucidate the incidence, clinical characteristics, and short-term outcome of delayed thyroid stimulating hormone (TSH) elevation (dTSH) in a large cohort of newborns admitted to the neonatal intensive care unit.

STUDY DESIGN

Data were gathered from a cohort of 13 201 newborns admitted to the neonatal intensive care unit born between January 1, 2008, and October 31, 2014, who underwent TSH measurements because of low T4 levels on the second screen. The data from the newborn screening program included gestational age, birth weight (BW), T4 levels, and short-term outcome.

RESULTS

Of 13 201 newborns, 333 (1:40) presented with dTSH (TSH >15 IU/L). dTSH had a peak proportion at gestational age of 37-39 weeks, and 66% of the patients had BW >1500 g. T4 levels in the 333 patients were negatively correlated with TSH levels (R = -0.505; P < .001), and significantly lower than levels in the other newborns: 5.9 ± 2.8 vs 7.6 ± 1.7 µg/dL; P < .001. TSH levels in dTSH newborns were already higher on the initial screen compared with the other newborns: 8.3 ± 5.2 vs 4.2 ± 3.7 IU/L; P < .001. Fifty-eight percent of 193 patients with dTSH were started on levothyroxine treatment.

CONCLUSIONS

dTSH has a higher incidence than previously reported, especially among newborns with BW >1500 g. Relatively high TSH and low T4 levels on the initial and second screen respectively are predictors for dTSH. Levothyroxine treatment is required in most cases.

Normative Thyroid-Stimulating Hormone Values for Healthy Nigerian Newborns

BACKGROUND

Congenital hypothyroidism is a common congenital endocrine disorder prevailing all over the world. No nationwide screening exists for any sub-Saharan country. We present normative cord and capillary thyroid-stimulating hormone (TSH) values for healthy Nigerian newborns.

SUBJECTS AND METHODS

A cross-sectional study was carried out in 6 university hospitals in Nigeria between January 1 and December 31, 2013. Cord and heel blood placed on 4 concentric circles on a Whartman filter paper were analysed for TSH within 1 week of collection using AutoDelfia 1235 immunoassay (Perkin Elmer Wallace, Boston, Mass., USA) at Charité - Universitätsmedizin Berlin, Berlin, Germany. The mean TSH levels of the newborns were determined, considering their sex, birthweight, socioeconomic status, and birth city. The association between the mean TSH level and other parameters was determined by analysis of variance.

RESULTS

A total of 2,014 subjects were recruited during the study period. The mean TSH value for the subjects was 1.86 μIU/ml, and 98.1% of the newborns were within the 2.5th and 97.5th percentiles (range: 0.09-7.90 μIU/ml) of the TSH levels. We collected 247 cord and 1,767 heel samples, respectively, and the range was slightly higher in samples from cord blood.

CONCLUSION

The study highlights the normal reference values for capillary/cord TSH levels in term Nigerian newborns. TSH was higher in one region, attributable to earlier sampling, but was not influenced by gender, socioeconomic status, or birthweight.

Evolution to permanent or transient conditions in children with positive neonatal TSH screening tests in Sergipe, Brazil

OBJECTIVES

To assess the evolution to permanent or transient conditions in children with positive neonatal TSH tests in Sergipe, Brazil, from 2004 to 2010.

SUBJECTS AND METHODS

Out of 193,794 screened newborns, 713 presented a neonatal TSH level higher than the local cutoff (5.2 µU/mL). From the confirmatory serum TSH values, the children were diagnosed with initial congenital hypothyroidism (CH) or suspect CH. From the evolution, they were classified as permanent CH, hyperthyrotropinemia, or transient TSH elevation. The mean incidence of each final condition was calculated for the total period of time.

RESULTS

The initial diagnosis included 37 CH (18.1%) and 167 suspect CH (81.9%) cases. The final diagnosis included 46 cases of permanent CH (22.5%), 56 of hyperthyrotropinemia (27.5%), and 102 of transient TSH elevation (50.0%). Out of the 37 cases of initial CH, 23 (62.2%) had permanent CH, nine (24.3%) had hyperthyrotropinemia, and five (13.5%) had transient TSH elevation. Out of the 167 suspect CH cases, 23 (13.8%) had permanent CH, 47 (28.1%) had hyperthyrotropinemia and 97 (58.1%) had transient TSH elevation. The mean incidence after the follow up was 1:4,166 for permanent CH, 1:3,448 for hyperthyrotropinemia, and 1:1,887 for transient TSH elevation. Eighty-six percent of the children with an initial diagnosis of CH and 41.9% with suspect CH had a permanent condition (CH or hyperthyrotropinemia).

CONCLUSIONS

The follow-up of children with an initial diagnosis of CH or suspect CH is necessary to determine whether the disorder is permanent because predicting the evolution of the condition is difficult.

Permanent and Transient Congenital Hypothyroidism in Hamadan West Province of Iran

BACKGROUND

Primary congenital hypothyroidism (CH) is the most common treatable cause of mental retardation and can be classified into permanent and transient types. The purpose of this study was to determine the prevalence of permanent and transient congenital hypothyroidism (CH) in Hamadan, West province of Iran.

METHODS

The study population included all cases with primary congenital hypothyroidism, which were confirmed by thyroid function tests (TSH levels ≥ 10 mIU/L). All these patients had been followed up at the outpatient pediatric endocrine clinic of Besat hospital (Hamadan, Iran) for a period of time between May 2006 and March 2013. Biochemical findings at diagnosis and detailed medical records were collected. Patients were considered as permanent hypothyroidism if their TSH level was 10 (mIU/l) during 6 - 12 months of treatment. Also three years old patients with TSH level > 10 mU/L during one or three months after discontinuation of levothyroxine treatment were considered as permanent hypothyroidism.

RESULTS

A total of 164 children (49.9% male and 50.6% female) diagnosed with CH completed the study. Female/male ratio was 1.02/1. The incidence of CH was about 1/1250 in Hamadan, West province of Iran. Of the 164 patients, 105 cases (64 %) were diagnosed as permanent CH and other 59 cases (36%) were proven to have transient hypothyroidism. Female to male ratio was 1.14 in patients suffering from permanent CH and 0.8 in patients with transient CH. The initial TSH level was found to be significantly higher in cases with permanent CH compared to the patients with transient CH (P = 0.001). Mean TSH level during the first year of treatment was higher in permanent CH cases compared to transient cases (P = 0.001). Children with transient CH had a lower TSH serum level during the three years of treatment (P = 0.000). A significant statistical difference was not found between the genders and permanent or transient CH (P = 0.352). Co-occurring congenital anomalies and birth order were significantly different between two groups (P = 0.028 and P = 0.024, respectively).

CONCLUSIONS

Our regional follow-up data showed that about 40% of newborns with primary CH had transient thyroid dysfunction. Our results further clarify our previous research by providing evidences on the incidence rate of CH. The incidence rates of CH as well as transient type of CH in our region were higher than those reported by other studies which have been conducted in other regions of the world. The initial TSH level was the strongest predictor of treatment cessation. Given the high incidence of transient CH in our region, further studies are needed to confirm the etiology and to provide considerable insight into preventive and/or the treatment strategies.

Liothyronine Improves Biochemical Control of Congenital Hypothyroidism in Patients with Central Resistance to Thyroid Hormone

OBJECTIVE

To assess whether adding liothyronine (LT3) to levothyroxine (LT4) monotherapy normalizes serum thyrotropin (TSH) and thyroxine (T4) concentrations in children with congenital hypothyroidism and central resistance to thyroid hormone.

STUDY DESIGN

We retrospectively studied 12 patients with congenital hypothyroidism and central resistance to thyroid hormone (6 treated with LT3+LT4 combined therapy and 6 treated with LT4 monotherapy). In patients receiving combined therapy, we compared serum concentrations of TSH, T4, and triiodothyronine before and after addition of LT3. We used repeated measures analysis to compare thyroid function in participants receiving combined therapy vs monotherapy, while accounting for age and intrasubject correlation.

RESULTS

In patients receiving combined therapy, the addition of LT3 was associated with normalization of mean TSH (9.2 vs 4.5 mIU/L, P = .002), a lower proportion of TSH values greater than 10 mIU/L (35% vs 8%, P = .03), and a decrease in mean serum T4 by 23 ± 9% (P < .001). Compared with patients receiving LT4 monotherapy, patients receiving combined therapy had lower mean TSH (8.5 ± 0.9 vs 4.3 ± 0.4, P < .001), lower odds of TSH elevation greater than 10 mIU/L (OR 0.20, 95% CI 0.10-0.41, P < .001), and lower odds of T4 elevation (OR 0.21, 95% CI 0.04-1.09, P = .06). LT3 treatment did not increase serum T3 levels significantly.

CONCLUSION

The addition of LT3 to LT4 monotherapy facilitates normalization of both serum TSH and T4 in patients with congenital hypothyroidism and central resistance to thyroid hormone. Larger prospective studies are needed to confirm these findings and to determine the effect of combined therapy on neurodevelopmental outcomes.

Neonatal Screening for Congenital Hypothyroidism with Focus on Developing an Indian Screening Programme

Neonatal screening for congenital hypothyroidism, along with eradication of iodine deficiency in large parts of the world, has made it possible to prevent the development of permanent neurological impairment due to thyroid hormone deficiency in the developing brain. The first successful screening programme was demonstrated in Canada in 1973 and since then it has been standard of care in most developed societies. In India there is no national programme for neonatal screening, and screening is only done in selected larger hospitals on newborns whose parents fund it. This review summarises the current understanding of the various strategies for newborn screening that could potentially be employed in India with resource constraints. Once a case is detected, the further evaluation and determination of etiology is summarised. Treatment and long term follow-up with levothyroxine replacement is also described in detail as per current understanding.

Frequency of thyroid status monitoring in the first year of life and predictors for more frequent monitoring in infants with congenital hypothyroidism

BACKGROUND

The essential role of thyroid hormones for normal brain development during a critical period of life is well established. Neonatal screening programs for congenital hypothyroidism (CH) enable early detection of patients and attainment of euthyroid status as quickly as possible. Adequate and accurate monitoring of thyroid function is necessary. In the study we aimed to determine the periodicity of thyroid function testing in the first year of life (3-month intervals versus <3-month intervals monitoring).

METHODS

We retrospectively analyzed charts of CH children from Macedonia detected on neonatal screening during a 3-year period (2011-2014). Needs for monthly thyroid monitoring were defined according to the recommendations: a dose change within a month of a previous control, values of T4/FT4 not in the upper half of the reference range, and a high or very low thyroid-stimulating hormone (TSH) value.

RESULTS

Monthly thyroid testing was indicated in more than a third of CH patients during the first year of life. Children who needed more frequent monitoring intervals had a higher initial value of TSH (p=0.032) and a lower value of T4 (p=0.038) than those requiring less frequent monitoring. The sex, birth weight, age of treatment onset, initial L-thyroxine dose, and L-thyroxine dose at 1-year of age in our study were not predictive factors for more frequent thyroid monitoring.

CONCLUSIONS

Children with severe hypothyroidism at birth are potential candidates for more frequent thyroid monitoring during the first year of life, although the individual patient approach should not be avoided as variations in TSH values are very common.

Congenital Hypothyroidism: Optimal Initial Dosage and Time of Initiation of Treatment: A Systematic Review

CONTEXT

Appropriate management of neonates, tested positive for congenital hypothyroidism (CH), in particular, the initial dosage of levothyroxine and the time of initiation of treatment is a critical issue. The aim of this study was to assess all current evidence available on the subject to ascertain the optimal initial dose and optimal initiation time of treatment for children with CH.

EVIDENCE ACQUISITION

In this study, all published research related to the initiation treatment dose and the onset time of treatment in congenital hypothyroidism were reviewed. The searched electronic databases included Medline, Science direct, Scopus EMBASE, PsycINFO, Cochrane, BIOSIS and ISI Web of Knowledge. Additional searches included websites of relevant organizations, reference lists of included studies, and issues of major thyroid and pediatrics journals published within the past 35 years. Studies were included if they were written in English and investigated levothyroxine dose or timing of treatment or both, used for the treatment of children with congenital hypothyroidism.

RESULTS

Two thousand three hundred and seventy-four articles (excluding duplicates) were retrieved from the primary search. After reviewing the titles, abstracts and full-texts of studies, eventually, 22 studies were found that met our inclusion criteria. Amongst these, 17 and 12 evaluated outcomes of different treatment doses and treatment timing, respectively. Overall, the majority of these studies emphasized the initial high dose of levothyroxine and early treatment of newborns with hypothyroidism. There were, however, some studies that disagreed with increasing levothyroxine dose at initiation of treatment.

CONCLUSIONS

Considering the results of this review, apparently there is no difference in opinion regarding the early initiation of treatment, whereas determining the optimal dose of levothyroxine for start of treatment in CH patients still remains a controversial issue, demonstrating the need for further studies, despite the fact that use of high doses can lead to rapid normalization of biochemical indices, although this may cause complications.

Can One Predict Resolution of Neonatal Hyperthyrotropinemia?

OBJECTIVE

To identify predictors of transience vs permanence of neonatal hyperthyrotropinemia. We hypothesized that infants with greater severity of perinatal stress are more likely to have transient thyrotropin elevations.

STUDY DESIGN

We retrospectively studied infants diagnosed with hyperthyrotropinemia between 2002 and 2014, following them for up to 12 years after diagnosis. Patients were divided into 3 groups: transient hyperthyrotropinemia (treatment was never prescribed), transient congenital hypothyroidism (treatment started but discontinued), and permanent congenital hypothyroidism (withdrawal unsuccessful or not attempted). We performed univariate and multiple logistic regression analyses, including and excluding infants with maternal thyroid disease.

RESULTS

We included 76 infants, gestational age mean (±SD) 34.2 (±5.7) weeks, evaluated for hyperthyrotropinemia. Thirty-five (46%) were never treated, and 41 (54%) received levothyroxine. Of the treated patients, 16 successfully discontinued levothyroxine, and for 25 withdrawal either failed or was not attempted. We found that male patients were almost 5 times more likely than female patients to have transient neonatal hyperthyrotropinemia (OR 4.85; 95% CI 1.53-15.37). We documented greater maternal age (31.5 ± 5.48 years vs 26 ± 6.76 years, mean ± SD, P = .02), greater rate of cesarean delivery (86.7% vs 54.2%; P = .036), and retinopathy of prematurity (37.5% vs 8%; P = .02) in the group with transient congenital hypothyroidism vs the group with permanent congenital hypothyroidism.

CONCLUSION

The results show transience of neonatal thyrotropin elevations in a majority of patients and suggest a possible association of hyperthyrotropinemia with maternal and perinatal risk factors.

Down syndrome-A narrative review with a focus on anatomical features

Down syndrome (DS) is the most common aneuploidy of chromosome 21, characterized by the presence of an extra copy of that chromosome (trisomy 21). Children with DS present with an abnormal phenotype, which is attributed to a loss of genetic balance or an excess dose of chromosome 21 genes. In recent years, advances in prenatal screening and diagnostic tests have aided in the early diagnosis and appropriate management of fetuses with DS. A myriad of clinical symptoms resulting from cognitive, physical, and physiological impairments caused by aberrations in various systems of the body occur in DS. However, despite these impairments, which range from trivial to fatal manifestations, the survival rate of individuals with DS has increased dramatically from less than 50% during the mid-1990s to 95% in the early 2000s, with a median life expectancy of 60 years reported recently. The aim of this narrative review is to review and summarize the etiopathology, prenatal screening and diagnostic tests, prognosis, clinical manifestations in various body systems, and comorbidities associated with DS. Clin. Anat. 29:568-577, 2016. © 2015 Wiley Periodicals, Inc.

Aplicación del Programa de Tamizaje para el diagnóstico de Hipotiroidismo Neonatal en el Hospital San Juan de Dios Guatemala

Introducción: El diagnóstico de hipotiroidismo neonatal es una condición considerada de urgencia por el grave daño cerebral que induce la falta de hormonas tiroideas al no ser reemplazadas. Objetivo: El presente trabajo tuvo como propósito evaluar la metodología y la aplicación del programa de tamizaje para el diagnóstico de hipotiroidismo neonatal y determinar su incidencia en el Hospital General San Juan de Dios de Guatemala (HGSD).  Metodología:  Estudio de cohorte, retrospectivo, analizando los resultados de TSH de los neonatos nacidos vivos del 1 de enero al 31 de diciembre del año 2017, que fueron tamizados, utilizando la base de datos del laboratorio del HGSD. El valor de corte de TSH utilizado, fue ≥ 20 µU/ml. El diagnóstico fue confirmado con una segunda medición de TSH, utilizando el mismo valor de corte, iniciando ese mismo día el tratamiento hormonal de reemplazo. Resultados. La incidencia de hipotiroidismo neonatal fue de 1:3,707 recién nacidos y la aplicación del programa de tamizaje fue del 96.1% durante el período de estudio. Conclusiones. La cobertura del programa es buena y comparable con la reportada en otros países. El programa de tamizaje debe contar con personal propio, pues sólo de esta manera, podrá lograrse el 100% de cobertura y acortar el período de tiempo para confirmar el diagnóstico e iniciar el tratamiento. Palabras clave: hipotiroidismo neonatal, TSH, valor de corte

Transient Congenital Hypothyroidism in Turkey: An Analysis on Frequency and Natural Course

OBJECTIVE

Prevalence of congenital hypothyroidism (CH) in Turkey at birth was reported to be as high as 1:650 in 2008-2010. Incidence rates of permanent and transient CH separately are unknown due to lack of follow-up data. We aimed to evaluate the impact of transient hypothyroidism on increasing incidence of CH and to determine the natural course and the clinical, biochemical, and imaging characteristics of transient CH.

METHODS

Baseline and follow-up data of the infants with CH detected at screening in six provinces in the Black Sea Region were analyzed retrospectively during a time period covering the years 2008-2010.

RESULTS

Among 138 cases (48% female), 16 (12%) showed transient hyperthyrotropinemia which resolved without intervention. Of the treated 122 cases, 63 (52%) had transient CH. While its frequency was 35% in 2008, it increased to 56% in 2009-2010, following a lowering of the thyroid stimulating hormone cutoff value. The frequency was higher in inland provinces than in coast (67% vs. 43%; p=0.01).Clinical characteristics of permanent and transient cases were similar except female-to-male sex ratios (1.5:1 vs. 0.6:1; p=0.02). L-thyroxine was discontinued in 70% of transient cases before 3 years of age at a median age of 19 (2-36) months. The only indication for early discontinuation of treatment was a low L-thyroxine dose, which was 1.25±0.27 µg/kg/day at withdrawal time.

CONCLUSION

Our regional follow-up data showed that more than half of newborns with primary CH had transient thyroid dysfunction. In the majority of cases, discrimination between transient and permanent CH can be made before age 3 years, as indicated by cessation of L-thyroxine treatment.

Thyroid Dysfunction in Children Exposed to Iodinated Contrast Media

CONTEXT

Iodinated contrast media (ICM) is routinely used in imaging studies and contains several 100-fold the recommended daily allowance of iodine.

OBJECTIVE

To determine whether children exposed to ICM have a higher risk of iodine-induced thyroid dysfunction.

DESIGN

This was a single-institution case-control study, examining patients with incident thyroid dysfunction aged less than 18 years from 2001 to 2015. Cases were matched 1:1 to euthyroid controls by age, sex, and race.

SETTING

This was a single-institution case-control study occurring at tertiary care center.

PARTICIPANTS

Cases were defined as those with thyroid dysfunction (by International Classification of Diseases, Ninth Revision diagnosis codes and/or 2 consecutive abnormal serum TSH values <6 mo apart). We analyzed 870 cases matched to 870 controls (64% female, 51% White).

MAIN OUTCOMES MEASURES

Using conditional logistic regression, the association between ICM exposure and the primary outcome, thyroid dysfunction, occurring within 2 years of exposure was assessed.

RESULTS

Sixty-nine patients received ICM, including 53 (6%) among cases and 16 (2%) among controls. The risk of incident hypothyroidism was significantly higher after ICM exposure (odds ratio 2.60; 95% confidence interval, 1.43-4.72; P < .01). The median interval between exposure and onset of hypothyroidism was 10.8 months (interquartile range, 6.6-17.9). In hypothyroid cases, the median serum TSH concentration was 6.5 mIU/L (interquartile range, 5.8-9.6).

CONCLUSIONS

ICM exposure increases the risk of incident hypothyroidism in pediatric patients. Children receiving ICM should be monitored for iodine-induced thyroid dysfunction, particularly during the first year after exposure.

Neonatal Thyroid-Stimulating Hormone Screening as a Monitoring Tool for Iodine Deficiency in Turkey

OBJECTIVE

Thyroid-stimulating hormone (TSH) level in neonates is recommended as an indicator for presence of iodine deficiency (ID) at a population level and as a monitoring tool in programs of iodine supplementation. The purpose of this study, based on data from the National Newborn Screening Program (NNSP) for congenital hypothyroidism (CH) in 2014, was to analyze neonatal TSH levels to predict the current status of iodine nutrition in Turkey.

METHODS

According to screening methodology, heel-prick blood samples of newborns were collected on filter paper cards usually on day 3-5 after birth (or shortly before discharge). Results of samples collected >48 h after birth were analyzed. The degree of severity of ID was assessed by using the epidemiologic criteria of the World Health Organization (WHO). Elevated TSH levels (>5 mIU/L) were processed and classified according to province, region, birth season, and sampling time.

RESULTS

A total of 1,298531 newborns were registered in the NNSP for the CH database. Of those, 1,270311 newborns had screening results collected >48 h after birth and were included in the statistical analyses. The national prevalence of elevated TSH was 7.2%. While the Gaziantep sub-region had the highest TSH elevation rate (15.9%), the Tekirdağ sub-region had the lowest rate (4.0%; p<0.001). Seasonal variations were also significant, and the elevated TSH prevalence rate was highest in winter (7.4%; p<0.001).

CONCLUSION

National CH screening results suggest that Turkey may still be mildly iodine deficient. Nationwide studies should be performed for direct assessment and monitoring of iodine status in vulnerable populations to confirm accuracy of our results.

Preconception Care: A New Standard of Care within Maternal Health Services

Emerging research suggests that much pediatric affliction has origins in the vulnerable phase of fetal development. Prenatal factors including deficiency of various nutrients and exposure to assorted toxicants are major etiological determinants of myriad obstetrical complications, pediatric chronic diseases, and perhaps some genetic mutations. With recent recognition that modifiable environmental determinants, rather than genetic predestination, are the etiological source of most chronic illness, modification of environmental factors prior to conception offers the possibility of precluding various mental and physical health conditions. Environmental and lifestyle modification through informed patient choice is possible but evidence confirms that, with little to no training in clinical nutrition, toxicology, or environmental exposures, most clinicians are ill-equipped to counsel patients about this important area. With the totality of available scientific evidence that now exists on the potential to modify disease-causing gestational determinants, failure to take necessary precautionary action may render members of the medical community collectively and individually culpable for preventable illness in children. We advocate for environmental health education of maternity health professionals and the widespread adoption and implementation of preconception care. This will necessitate the translation of emerging knowledge from recent research literature, to health professionals, to reproductive-aged women, and to society at large.

Case Report: The Specter of Untreated Congenital Hypothyroidism in Immigrant Families

Newborn screening has dramatically reduced rates of untreated congenital hypothyroidism (CH). However, in low-income nations where newborn screening programs do not exist, untreated CH remains a significant health and societal challenge. The goal of this report is to alert health care providers about the potential of undiagnosed CH in unscreened immigrant children. We report 3 siblings of Somali descent with CH who started treatment with levothyroxine at age 0.5 years, 7.7 years, and 14.8 years and were followed for 8 years. This case series demonstrates a spectrum of severity, response to treatment, and neurocognitive and growth outcomes depending on the age at treatment initiation. Patient 1, now 22 years old, went undiagnosed for 14.8 years. On diagnosis, his height was -7.5 SDs with a very delayed bone age of -13.5 SDs. His longstanding CH was associated with empty sella syndrome, static encephalopathy, and severe musculoskeletal deformities. Even after treatment, his height (-5.2 SDs) and cognitive deficits remained the most severe of the 3 siblings. Patient 2, diagnosed at 7.7 years, had moderate CH manifestations and thus a relatively intermediate outcome after treatment. Patient 3, who had the earliest diagnosis at 0.5 years, displayed the best response, but continues to have residual global developmental delay. In conclusion, untreated CH remains an important diagnostic consideration among immigrant children.

Effect of maternal and neonatal factors on cord blood thyroid stimulating hormone

BACKGROUND

Congenital hypothyroidism (CH) is most common preventable cause of mental retardation in children. Cord blood Thyroid Stimulating Hormone (CBTSH) level is an accepted screening tool for CH.

OBJECTIVES

To study CBTSH profile in neonates born at tertiary care referral center and to analyze the influence of maternal and neonatal factors on their levels.

DESIGN

Cross retrospective sectional study.

METHODS

Study population included 979 neonates (males = 506 to females = 473). The CBTSH levels were estimated using electrochemiluminescence immunoassay on Cobas analyzer. Kit based cut-offs of TSH level were used for analysis. All neonates with abnormal CBSTH levels, were started on levothyroxine supplementation 10 μg/Kg/day and TSH levels were reassessed as per departmental protocol.

RESULTS

The mean CBTSH was 7.82 μIU/mL (Range 0.112 to 81.4, SD = 5.48). The mean CBTSH level was significantly higher in first order neonates, neonates delivered by assisted vaginal delivery and normal delivery, delivered at term or preterm, neonates with APGAR score <5 and those needing advanced resuscitation after birth. The CBTSH level >16.10 and <1.0 μIU/mL was found in 4.39 % and 1.02 % neonates respectively. The prevalence rate of CBTSH level >16.1 μIU/mL was significantly higher in neonates delivered by assisted vaginal delivery and normal delivery, term and preterm neonates, APAGR score of <5, presence of fetal distress, need for resuscitation beyond initial steps and in those with birth weight of <1.5 Kg. Three neonates were confirmed to have CH after retesting of TSH level.

CONCLUSIONS

The CBTSH estimation is an easy, non-invasive method for screening for CH. The cutoff level of CB TSH (μIU/mL) >16.10 and <1.0 led to a recall of 5.41% of neonates which is practicable given the scenario in our Country. The mode of delivery and perinatal stress factors have a significant impact on CBTSH levels and any rise to be seen in the light of these factors. The prevalence rate of CH after recall was ~3 in 1000 live births.

Use of Tc-99 m thyroid scans in borderline congenital hypothyroidism

BACKGROUND

Mild or borderline congenital hypothyroidism [often referred to as mild neonatal hyperthyrotropinemia (MNH)] is characterized by an abnormal newborn screen (NBS), followed by mildly elevated TSH and normal FT4 on confirmatory testing. This condition is increasingly observed, but data regarding optimal management are limited.

OBJECTIVE

Examine the use of routine technetium thyroid scanning (TS) in the management of MNH.

METHODS

Retrospective study of infants with MNH between 2000 and 2011. We assessed the clinical course of infants with MNH according to TS results; as a comparator, infants with classic congenital hypothyroidism (CH) were analysed in parallel.

RESULTS

We identified 69 infants (52% boys) with MNH and 164 (34% boys) with classic CH. TS results were divided into four subgroups: no uptake in 7% of MNH vs 24% of classic CH (P < 0·01), decreased uptake/anatomical abnormalities in 39% vs 46% (p = NS), increased uptake in 35% vs 26% (p = NS) and normal uptake in 19% vs 4% (P < 0·01). In MNH, neither NBS-TSH, confirmatory TSH and FT4, mean LT-4 treatment doses and number of dose escalations, nor post-treatment FT4 and TSH differed among the four subgroups. In contrast, clinical features in infants with classic CH differed among the subgroups. Among MNH infants who reached 3 years of age, trial-off treatment was successful in 6 of 11 (55%) with no apparent difference in success rates among TS subgroups.

CONCLUSIONS

The information provided by TS during evaluation of MNH does not predict clinical course; obtaining these scans in infants with MNH may not be an effective use of healthcare resources.

Thyroid Functions in Healthy Infants during the First Year of Life

OBJECTIVE

To study the pattern of thyroid function testing in healthy newborns during the first year of life.

STUDY DESIGN

We used the computerized database of a health management organization. Among the 18,507 infants insured by the Clalit Health Services born in the Sheba Medical Center between 2002 and 2007, 652 full-term healthy newborns with birth weight >2 kg and no significant perinatal morbidity underwent thyrotropin (TSH) determination as outpatients in their first year of life. The Clalit Health Services database provided demographic data, laboratory results, and dispensed medications for the newborns and their mothers.

RESULTS

Initial serum TSH levels were within normal range (0.35-5.5 mIU/L) in 91.1%, elevated (> 5.5-≤ 10 mIU/L) in 8.3%, and highly elevated (>10 mIU/L) in 0.6% of the studied cohort. The 97.5 and 2.5 percentile values were 7.4 and 0.74 mIU/L, respectively. TSH measurements were repeated in 34.2%, 72.2%, and 100% of children with normal, elevated, and highly elevated initial levels, respectively; results were normal in 96%, 74%, and 50% of patients with initial normal, elevated, and highly elevated TSH, respectively; repeated TSH levels were > 97.5 percentile in 35% of patients with initial TSH > 97.5 percentile compared with 1% with first results < 97.5 percentile (P = .005). Only 4 (0.6%) of the 652 newborns included in the study received thyroxin treatment.

CONCLUSION

The normal TSH levels found in most healthy infants with normal thyroid screening and the spontaneous normalization of TSH values below 7.4 mIU/liter, substantiate the reliability of the screening, reduce unnecessary work-up and unnecessary thyroxin treatment of neonates meeting these criteria.

Changes in the incidence and etiology of congenital hypothyroidism detected during 30 years of a screening program in central Serbia

Congenital hypothyroidism (CH) is the most frequent congenital endocrine disorder. The purpose of the present study was to determine the incidence of CH in Central Serbia from 1983 to 2013. Newborn screening for CH was based on measuring neonatal thyroid-stimulating hormone (TSH) using a 30 mU/l cutoff (CO) until 12/1987 (P1), 15 mU/l until 12/1997 (P2), 10 mU/l until 12/2006 (P3), and 9 mU/l thereafter (P4). During the study period, there were 1,547,122 live births screened for CH. Primary CH was detected in 434 newborns, with incidence of 1:3728. With gradual lowering of the CO, the incidences of CH increased from 1:5943 in P1 to 1:1872 in P4 (p < 0.001). Incidence of CH with ectopic and enlarged gland doubled (p < 0.001), while prevalence of athyreosis remained relatively constant. The most prominent finding was the increase in the transient CH from none in P1 to 35 % of all CH patients in P4.

CONCLUSION

The overall incidence of CH in Central Serbia during study period nearly tripled, with a significant increase in almost all etiological categories, and was associated with lowering TSH cutoffs as well as other yet unidentified factors. Further studies are needed to identify other factors associated with increasing incidence of CH.

WHAT IS KNOWN

Congenital hypothyroidism (CH) is the main cause of preventable mental retardation. Recent reports have indicated a progressive increase in the incidence of primary CH throughout the world, partially explained by lowering of the TSH cutoff values.

WHAT IS NEW

During the study period associated with lowering of the TSH cutoffs, the overall incidence of CH in Serbia tripled, including transient CH, ectopy, and dyshormonogenesis, while prevalence of athyreosis remained stable during 30 years. Significant increase in the incidence of both permanent and transient CH was observed, associated with lowering of TSH cutoffs as well as other yet unidentified factors.

Transient versus Permanent Congenital Hypothyroidism after the Age of 3 Years in Infants Detected on the First versus Second Newborn Screening Test in Oregon, USA

BACKGROUND/AIMS

The newborn screening (NBS) program in Oregon, USA, collects two routine specimens in all infants. The aim of our study was to determine the incidence of permanent versus transient congenital hypothyroidism (CH) in infants detected on the first versus second screening test.

METHODS

Thyroid function was determined in infants after the age of 3 years diagnosed with CH and born in Oregon between 2005 and 2011. Permanent hypothyroidism was defined as a TSH rise >10 mIU/ml after the first year on treatment or a TSH rise >6 mIU/ml with temporary discontinuation of l-thyroxine after the age of 3 years.

RESULTS

Of the cases detected on the first test, 72 of 87 (83%) were permanent and 15 of 87 (17%) were transient, while of the cases detected on the second test, 5 of 22 (23%) were permanent and 17 of 22 (77%) were transient (OR 16.3, p < 0.001). There was a female preponderance detected on the first screen versus a male preponderance on the second screen. Blood spot and serum thyroid function tests at diagnosis, before treatment, were not meaningfully different between the two groups. The mean l-thyroxine dose at the age of 3 years was greater on the first screen: 61.2 versus 36.6 μg/day.

CONCLUSIONS

Infants detected on the second NBS specimen have a higher incidence of transient CH. © 2016 S. Karger AG, Basel.

The role of ¹²³I imaging in the evaluation of infants with mild congenital hypothyroidism

BACKGROUND/AIMS

Controversy exists regarding the diagnosis and treatment of mild congenital hypothyroidism (MCH). We studied the value of (123)I imaging in patients with MCH.

METHODS

Retrospective chart review of infants and children <4 years of age who underwent (123)I imaging: group 1 = MCH [thyroid-stimulating hormone (TSH) <25 µIU/ml, normal free T4/T3], group 2 = severe congenital hypothyroidism (TSH ≥25 µIU/ml), and group 3 = MCH in infancy imaged after treatment withdrawal at age 3 years. Data collected included 4- and 24-hour (123)I uptake, TSH, free T4/total T3 at imaging, age at imaging, and levothyroxine (L-T4) dose at 1 year of.

RESULTS

Thirty-six patients underwent (123)I imaging. In group 1 (n = 20, median TSH: 8.49 µIU/ml), 85% had abnormal imaging consistent with dyshormonogenesis. Two patients were referred after 1 year of age. The median age at imaging for the remaining 18 patients was 54 days. Median L-T4 dose at 1 year of age for these 18 patients was 2.8 μg/kg, which is consistent with dyshormonogenesis. Ninety-one percent of group 2 (n = 11, median TSH: 428.03 µIU/ml) had abnormal imaging. The median age at imaging was 13 days. Four patients in group 3 had abnormal (123)I imaging and restarted treatment.

CONCLUSION

(123)I imaging is a valuable tool for evaluation, diagnosis, and treatment of MCH.

Severe unsuspected maternal hypothyroidism discovered after the diagnosis of thyrotropin receptor-blocking antibody-induced congenital hypothyroidism in the neonate: failure to recognize and implications to the fetus

BACKGROUND

Whereas most adequately treated children with congenital hypothyroidism (CH) do well neurodevelopmentally, when both the maternal and fetal thyroid glands are compromised, significant cognitive delay can occur despite early and aggressive postnatal therapy. Maternal thyrotropin-stimulating hormone receptor (TSHR)-blocking antibodies (Abs) can be transmitted to the fetus and cause combined maternal-fetal hypothyroidism. Current guidelines recommend their measurement only if mothers have known autoimmune thyroid disease, there is a history of a previously affected sibling, or when transient CH is suspected.

RESULTS

We report 3 infants in whom the diagnosis of maternal hypothyroidism was not known and was identified only after CH was diagnosed in their babies. One of these infants had developmental delay despite rapid normalization of thyroid function postnatally. All 3 mothers had potent TSHR Abs in serum, but thyroid peroxidase Abs and thyroglobulin Abs were detectable in only 2 of them.

CONCLUSIONS

TSHR-blocking Ab-induced CH should be suspected in any baby with CH irrespective of the known family history, especially if the hypothyroidism is severe and a eutopic thyroid gland is demonstrated on imaging. Measurement of TSHR Abs is necessary to establish the diagnosis; the presence of other thyroid Abs is insufficiently sensitive and may miss some cases.

Levothyroxine requirement in congenital hypothyroidism: a 12-year longitudinal study

The aim of the replacement therapy with levothyroxine in congenital hypothyroidism (CH) is to correct hypothyroidism and ensure normal growth and neuropsychological development. Few data are available about the appropriate dose during childhood and early adolescence; therefore, we performed a multicenter observational study in a large population of patients with CH to assess the required levothyroxine dose to obtain euthyroidism. We recruited 216 patients with permanent CH classified into three groups (agenesia, ectopia, and in situ gland) on the basis of the thyroid imaging. The levothyroxine dose was recorded at 6 and 12 months and then yearly until 12 years of age. The daily levothyroxine requirement progressively decreased during the follow-up, irrespective of etiology. It was significantly lower in patients with in situ gland than in patients with athyreosis during the entire study period and with ectopic gland from the age of 1 year. The levothyroxine requirement at 6 months of age was correlated with the requirement at each later time-point. The daily dose was modified less frequently in patients with in situ thyroid (36 %) than in patients with ectopic gland (41.4 %) or with athyreosis (43.6 %). Patients with in situ gland required a lower dose than the other two subgroups. The dose at 6 months seems predictive of the requirement until 12 years of age. Euthyroidism may be achieved in pre-school and in-school patients by 3-4 and 2-3 µg/kg/day (70-90 and 60-80 µg/m(2)/day) of levothyroxine, respectively.

Delayed Diagnosis of Hypothyroidism in Children: Report of 3 Cases

Introduction:

Hypothyroidism is the most common endocrine disorder in children and presented with various sign and symptoms; its diagnosis needs a high index of suspicion.

Case Presentation:

We report 3 cases with unusual presentations of hypothyroidism and with delay in diagnosis that referred to Pediatric Endocrine Outpatient Clinic in Mashhad University of Medical Sciences, Mashhad, Iran with different clinical manifestations. They had decreased Thyroxin (T4) and increased thyroid stimulating hormone (TSH) levels. One case had mental retardation and deafness, but the other two cases had normal neurodevelopment. Some additional interesting findings were as follows: short stature, delayed bone age, teeth eruption impairment, hair loss, anemia and hypercholesterolemia, persistent and long-term constipation that had led to several abdominal surgeries. After a year of hormonal replacement therapy, their growth parameters and hematological values improved.

Conclusions:

We recommend thyroid hormonal evaluation for any children with short stature, especially with delayed bone age, in order to detect and treat hypothyroidism at the right time. It seems that more attention to pediatric growth is necessary.

Final height in Italian patients with congenital hypothyroidism detected by neonatal screening: a 20-year observational study

BACKGROUND

Linear growth and final height are reported as normal in congenital hypothyroid patients in the neonatal screening era.

METHODS

We evaluated the final height in 215 patients with congenital hypothyroidism to assess if it improved over the last 2 decades.

RESULTS

Final height (-0.1 ± 1.0 SDS) was higher than target height (-0.8 ± 1.0 SDS, p < 0.001) and not different among the 4 quartiles for birthdate. It was correlated with target height (r(2) = 0.564, p < 0.001) and height at puberty onset (r(2) = 0.685, p < 0.001), but not with age at diagnosis or the starting LT4/kg/day dose. The curve fitting analysis showed that the age at diagnosis progressively decreased during the 20-year study period, while the target height and the starting LT4/kg/day increased. Final height was not affected by the birthdate, the age at diagnosis, the starting LT4 dose.

CONCLUSIONS

The final height is higher than the target height, but despite the improvement in the screening and the treatment, it did not improve over the last 20 years. These findings are in keeping with the described secular trend and suggest that earlier diagnosis and replacement therapy do not significantly modify final height in these patients.

Congenital Hypothyroidism: An Audit and Study of Different Cord Blood Screening TSH Values in a Tertiary Medical Centre in Malaysia

Mothers are often discharged within 24 hours in most Asian countries. Therefore, our screening programs for congenital hypothyroidism (CH) must consider the value of cord blood TSH. Our objectives were to compare the incidence of CH, positive predictive values, and recall rates using different cord blood TSH values. We also reviewed the results of the second-screening program for premature babies. 99.7% (n=25,757) of all newborns were screened from 1st January 2009 to 31st December 2013. Babies with cord blood TSH > 25 mIU/L or 20–25 mIU/L and FT4<20 pmol/L were recalled for a repeat venous TSH and FT4 on days 3–5 of life to confirm CH. Twenty-two babies were confirmed to have CH, an incidence of 1:1170. Five were premature. Eleven term babies had cord blood TSH>30 mIU/L and six had values 25.1–30 mIU/L. Lowering the recall cut-off value to 20 mIU/L would double the recall rate from 0.63% (n=163) to 1.3% (n=340) with no additional cases detected, whereas using 30 mIU/L would have missed 35% of cases. The incidence of CH was similar, 1:1515, when using either cut-off 20 mIU/L or cut-off 25 mIU/L but lower, 1:2380, when using 30 mIU/L. We recommend the screening cord blood TSH cut-off should be 25 mIU/L and screening for premature babies should be continued.

Guidelines for Mass Screening of Congenital Hypothyroidism (2014 revision)

Purpose of developing the guidelines: Mass screening for congenital hypothyroidism started in 1979 in Japan, and the prognosis for intelligence has been improved by early diagnosis and treatment. The incidence was about 1/4000 of the birth population, but it has increased due to diagnosis of subclinical congenital hypothyroidism. The disease requires continuous treatment, and specialized medical facilities should make a differential diagnosis and treat subjects who are positive in mass screening to avoid unnecessary treatment. The Guidelines for Mass Screening of Congenital Hypothyroidism (1998 version) were developed by the Mass Screening Committee of the Japanese Society for Pediatric Endocrinology in 1998. Subsequently, new findings on prognosis and problems in the adult phase have emerged. Based on these new findings, the 1998 guidelines were revised in the current document (hereinafter referred to as the Guidelines). Target disease/conditions: Primary congenital hypothyroidism. Users of the Guidelines: Physician specialists in pediatric endocrinology, pediatric specialists, physicians referring patients to pediatric practitioners, general physicians, laboratory technicians in charge of mass screening, and patients.

Ethics, genetics and public policies in Uruguay: newborn and infant screening as a paradigm

Uruguay is a middle-income country and the smallest in South America. Its population is under 3.3 million. The demographic and epidemiological characteristics are similar to those of developed countries, with a high burden associated with congenital anomalies. Infant mortality rate (IMR) decreased from 37/1000 live births, in 1980, to 8.8/1000, in 2013. This is largely explained by medical and social policies. IMR related to congenital anomalies, however, remained unchanged for the last 30 years. Therefore, programmes for prevention of congenital disorders were developed, such as the National Newborn Screening Programme. Mandatory, universal, free infant screening was implemented two decades ago. The Ministry of Public Health created the Comprehensive Plan on Birth Defects and Rare Diseases (PIDCER), to develop a strategic public policy tool enabling comprehensive, universal, quality care during their entire lifetime. Recent national legislation created provisions for newborn and infant screening, including for congenital hypothyroidism, phenylketonuria, congenital adrenal hyperplasia, cystic fibrosis and medium-chain acyl-CoA dehydrogenase, via blood spot test, otoacoustic emissions, systematic physical examination and hip ultrasound. We discuss how this programme was implemented, the current situation of rare diseases, the institution managing disability in Uruguay and the development of new laws based on the MPH's PIDCER. It illustrates how Uruguay is developing public policies in the genomic era, based both on science and bioethics.