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

Impact of Lowering TSH Cut-Off on Neonatal Screening for Congenital Hypothyroidism in Minas Gerais, Brazil

A higher incidence of primary congenital hypothyroidism (CH) has been related to increased sensitivity in neonatal screening tests. The benefit of treatment in mild cases remains a topic of debate. We evaluated the impact of reducing the blood-spot TSH cut-off (b-TSH) from 10 (Group 2) to 6 mIU/L (Group 1) in a public neonatal screening program. During the study period, 40% of 123 newborns with CH (n = 162,729; incidence = 1:1323) had b-TSH between 6 and 10 mIU/L. Group 1 patients had fewer clinical signs (p = 0.02), lower serum TSH (p < 0.01), and higher free T4 (p < 0.01) compared to those in Group 2 at diagnosis. Reducing the b-TSH cut-off from 10 to 6 mIU/L increased screening sensitivity, allowing a third of diagnoses, mainly mild cases, not being missed. However, when evaluating the performances of b-TSH cut-offs (6, 7, 8, 9, and 10 mIU/L), the lower values were associated with low positive predictive values (PPVs) and unacceptable increased recall rates (0.57%) for a public health care program. A proposed strategy is to adopt a higher b-TSH cut-off in the first sample and a lower one in the subsequent samples from the same child, which yields a greater number of diagnoses with an acceptable PPV.

Current Status of Newborn Bloodspot Screening Worldwide 2024: A Comprehensive Review of Recent Activities (2020-2023)

Newborn bloodspot screening (NBS) began in the early 1960s based on the work of Dr. Robert "Bob" Guthrie in Buffalo, NY, USA. His development of a screening test for phenylketonuria on blood absorbed onto a special filter paper and transported to a remote testing laboratory began it all. Expansion of NBS to large numbers of asymptomatic congenital conditions flourishes in many settings while it has not yet been realized in others. The need for NBS as an efficient and effective public health prevention strategy that contributes to lowered morbidity and mortality wherever it is sustained is well known in the medical field but not necessarily by political policy makers. Acknowledging the value of national NBS reports published in 2007, the authors collaborated to create a worldwide NBS update in 2015. In a continuing attempt to review the progress of NBS globally, and to move towards a more harmonized and equitable screening system, we have updated our 2015 report with information available at the beginning of 2024. Reports on sub-Saharan Africa and the Caribbean, missing in 2015, have been included. Tables popular in the previous report have been updated with an eye towards harmonized comparisons. To emphasize areas needing attention globally, we have used regional tables containing similar listings of conditions screened, numbers of screening laboratories, and time at which specimen collection is recommended. Discussions are limited to bloodspot screening.

Epidemiological profile of congenital hypothyroidism at a southern Brazilian state

Objective

To determine the incidence of congenital hypothyroidism (CH) over a 10-year period at the Reference Service in Neonatal Screening of the state of Rio Grande do Sul (RSNS-RS).

Subjects and methods

Historical cohort study including all newborns screened for CH by the RSNS-RS from January 2008 until December 2017. Data of all newborns with neonatal TSH (neoTSH; heel prick test) values ≥ 9 mIU/L were collected. According to neoTSH values, the newborns were allocated into two groups: Group 1 (G1), comprising newborns with neoTSH ≥ 9 mIU/L and serum TSH (sTSH) < 10 mIU/L, and Group 2 (G2), comprising those with neoTSH ≥ 9 mIU/L and sTSH ≥ 10 mIU/L.

Results

Of 1,043,565 newborns screened, 829 (0.08%) had neoTSH values ≥ 9 mIU/L. Of these, 284 (39.3%) had sTSH values < 10 mIU/L and were allocated to the G1 group, while 439 (60.7%) had sTSH ≥ 10 mIU/L and were allocated to the G2 group, and 106 (12.7%) were considered missing data. The overall incidence of CH was 42.1 per 100,000 newborns screened (95% confidence interval [CI] 38.5-45.7/100,000) or 1:2377 screened newborns. The sensibility and specificity of neoTSH ≥ 9 mIU/L were 97% and 11%; of neoTSH 12.6 mUI/L, 73% and 85% respectively.

Conclusion

In this population, the incidence of permanent and transitory CH was 1:2377 screened newborns. The neoTSH cutoff value adopted during the study period showed excellent sensibility, which matters for a screening test.

Predictive factors for the diagnosis of permanent congenital hypothyroidism and its temporal changes in Sergipe, Brazil - A real-life retrospective study

Objective

Congenital hypothyroidism (CH) can be permanent (PCH) or transient (TCH). While the importance of thyroxine in myelination of the brain is undisputed, the benefits to neurodevelopmental outcomes of TCH treatment are controversial. Our objectives were to determine predictive factors for PCH and verify its prevalence changes over time.

Subjects and methods

A total of 165 children were evaluated at 3 years of age to verify the diagnosis of PCH. 130 were submitted to a two-step cluster analysis, with the aim of grouping them into homogeneous clusters. The mean incidence of PCH and TCH was calculated from 2004 to 2010 and 2011 to 2015.

Results

Sixty-six children were diagnosed with PCH, and 99 were diagnosed with TCH. Eighty-one percent of PCH children and all TCH children with thyroid imaging had glands in situ. Eighty children (61.5%) were in Cluster 1, 8 children (6.2%) were in Cluster 2 and 42 children (32.3%) were in Cluster 3. No children had PCH in Cluster 1, while 87.5% of children in Cluster 2 and all children in Cluster 3 had PCH. The most important predictor for PCH was the initial serum TSH, which was marginally higher in importance than the blood spot TSH, followed by the initial serum free T4. The mean incidence of PCH (odds ratio: 1.95, 95% CI 1.36 to 2.95, p < 0.0001) and TCH (odds ratio 1.33, 95%, CI 1.02 to 1.77, p = 0,038) increased over time.

Conclusion

The most important PCH predictors are the initial serum TSH and the blood spot TSH. The mean incidence of both PCH and TCH in our series increased.

Effect of maternal and neonatal factors on neonatal thyroid stimulating hormone: Results from a population-based prospective cohort study in China

OBJECTIVE

Neonatal TSH screening is effective in detecting congenital hypothyroidism and estimating iodine status in a given population, but various factors influence TSH levels. The aim of this study was to evaluate the effect of maternal and neonatal factors on neonatal TSH levels.

DESIGN AND SETTING

Data were obtained from an ongoing prospective cohort study. A total of 988 pregnant women and their newborn infants participated in the study from April 2015 to May 2017 at Tianjin Maternal and Child Health Center and Tanggu Maternity Hospital in Tianjin, China. Maternal demographic information, including age, height, and parity, was recorded by questionnaire. Fasting blood and urinary samples were collected from all pregnant women. After parturition, information on gestation duration, mode of delivery, neonatal sex, neonatal TSH, neonatal birth weight, and neonatal birth height were recorded.

RESULTS

Maternal age, maternal BMI, gestation duration, parity, and neonatal birth weight and height were significantly correlated with neonatal TSH (p < 0.05). Quantile regression revealed that maternal age, TSH, FT₄, and gestation duration were positively correlated with neonatal TSH level. A logistic regression model identified maternal BMI, TSH, and birth height as risk factors for having neonatal TSH > 5 mIU/L (p < 0.05).

CONCLUSION

Neonatal TSH levels are dynamic and may be affected by several maternal and neonatal factors including maternal age, TSH, FT₄, and birth weight and height. Identification of these confounders is useful for assessing the status of neonatal thyroid development. STRENGTHS AND LIMITATIONS OF THIS STUDY: (1) Iodine deficiency disorder has generally been eliminated, so the median urinary iodine concentration of pregnancy is higher than 150 μg/L even in mildly or moderately iodine deficient areas. (2) Unlike many other studies, which did not consider the complexity of factors or examined only one or two variables, this study used a multivariate model to analyze the data. (3) This study examined numerous high-risk factors in pregnant women and considered the biological interrelation between them. Future studies should consider these confounding factors for neonatal TSH levels and establish a proper neonatal TSH range for monitoring the iodine status of a population or diagnosing congenital hypothyroidism.

Early Determinants of Thyroid Function Outcomes in Children with Congenital Hypothyroidism and a Normally Located Thyroid Gland: A Regional Cohort Study

BACKGROUND

An increase in the incidence of congenital hypothyroidism (CH) with a normally located gland has been reported worldwide. Affected individuals display transient or permanent CH during follow-up in childhood. This study aimed to determine the prevalence of transient CH and to investigate the possibility of distinguishing between transient and permanent CH in early infancy.

METHODS

This observational cohort study included all patients identified by systematic neonatal screening for CH in the northern Parisian region between 2002 and 2012 and treated for CH with a normally sited gland. A standardized data collection form was completed prospectively at diagnosis. Patients were classified during follow-up as having transient or permanent CH.

RESULTS

Of the 92 patients initially treated for CH with a normally located gland during the neonatal period, 49 (54%) had a transient form of CH after the cessation of levothyroxine (LT4) treatment at 1.5 (0.6-3.2) years of age. Multivariate analysis revealed that transient CH was associated with a lower likelihood of having a first-degree family history of CH (p = 0.03) and a lower LT4 dose at six months of age (p = 0.03) than permanent CH. Sex, ethnicity, neonatal problems (e.g., prematurity, being small for gestational age, and/or neonatal distress), iodine status, coexisting malformations, initial CH severity, and thyroid morphology at diagnosis had no effect. Receiver operating characteristics curve analysis showed that a cutoff of 3.2 μg/kg/day for LT4 dose requirement at six months of age had a sensitivity of 71% and a specificity of 79% for predicting transient CH, with values below this threshold considered predictive of transient CH.

CONCLUSION

In patients with CH and a normally located gland, these findings highlight the need to evaluate LT4 dose requirements early, at six months of age, particularly in patients with no family history of CH, for early identification of the approximately 50% of patients for whom treatment should be stopped.

Primary Care Provider Management of Congenital Hypothyroidism Identified Through Newborn Screening

OBJECTIVE

To assess Primary Congenital Hypothyroidism (CH) management patterns and feasibility of providing long-term care for patients with CH identified through newborn screening by Primary Care Providers (PCPs) in California and Hawaii.

STUDY DESIGN

A survey was mailed to all physicians (N=823) listed as the referral doctor for confirmed patients with CH identified through newborn screening programs in both states between 01/01/2009-12/31/2013. Information was collected on CH management patterns, barriers to providing care, and knowledge on CH treatment. Descriptive statistics and bivariate logistic regression results were reported.

RESULTS

206 PCPs completed the survey. Among these, 78% currently have patients with CH and 91% indicated willingness to provide long-term care to new patients with CH. Among PCPs currently caring for patients with CH, 17% managed CH by themselves with limited assistance from endocrinologists; 63% were involved in managing CH but endocrinologists played a larger role than PCPs; 19% were not involved in CH care. Only 49% of PCPs correctly answered questions regarding recommended follow-up frequencies and 23% knew the correct age for a trial off levothyroxine for suspected transient CH. Top two perceived barriers to providing long-term care included "need guidance or support from endocrinologists" (61%) and "not familiar with CH treatment guidelines" (28%).

CONCLUSION

The majority of PCPs surveyed are willing to provide long-term care to patients with CH, but need support from endocrinologists and increased knowledge about current treatment guidelines.