Thyroid Screening Program Research Articles

Incidence and risk factors of transient hypothyroxinemia of prematurity: a prospective cohort study.

Transient hypothyroxinemia of prematurity (THOP) is characterized by low thyroxine (T4) levels with normal thyroid-stimulating hormone (TSH) levels. This study aimed to determine the incidence and factors associated with THOP. This prospective cohort study included neonates who were born before 37 weeks of gestation in the neonatal intensive care unit (NICU) between April 2017 and December 2020. Serum TSH and free thyroxine (FT4) levels were routinely screened at 3-5 days and 2, 4, and 6-8 weeks postnatally. The criteria for diagnosis of THOP were a TSH level < 7 mU/L with a FT4 level < 0.8 ng/dL at any screening timepoint. The incidence of THOP in infants born before 28, 34, and 37 weeks of gestation was 39.5 (17/43), 8.4% (29/343), and 4.8% (35/722), respectively. A multivariate analysis revealed that a gestational age of < 28 weeks (adjusted odds ratio [aOR]: 5.35, 95% confidence interval [CI]: 1.89-15.13, p=0.002); 5-min Apgar score of ≤3 (aOR: 5.72, 95% CI: 2.2-14.89, p < 0.001); and treatment with aminophylline (aOR: 2.95, 95% CI: 1.08-8.11, p=0.037), dobutamine (aOR: 4.12, 95% CI: 1.55-10.98, p=0.004), or morphine (aOR: 4.91, 95% CI: 1.29-18.74, p=0.011) were associated with an increased risk of THOP. The TSH and FT4 levels in infants with THOP returned to normal ranges by 2 weeks of age. THOP is frequently found in preterm infants. An extremely low gestational age, a low Apgar score, and the use of certain medications in the NICU are risk factors for the development of THOP. Therefore, a thyroid screening program should be implemented for evaluating congenital hypothyroidism (CH) and THOP in preterm neonates in all settings.

Prevalence of congenital hypothyroidism in North Macedonia: data from a newborn screening program conducted for twenty years.

Congenital hypothyroidism (CH) is a common endocrine disorder that can be treated if timely detected by newborn screening, optimizing the developmental outcome in affected children. In the present study, we analyze the data of the national newborn thyroid screening program in North Macedonia collected over twenty years, including the CH prevalence as well as its geographical and ethnic variations. The thyroid-stimulating hormone (TSH) was measured on a filter paper blood spot sample using the DELFIA fluoroimmunometric assay. A TSH value of 15 mIU/L whole blood was used as the cutoff point until 2010 and 10 mIU/L thereafter. Out of 377,508 screened live births, a total of 226 newborns with primary CH were detected, providing an overall prevalence of 6.0 per 10,000. Lowering the TSH cutoff led to an apparently increased prevalence of the transient CH, from 0.2 to 2.4 per 10,000 live births (p < 0.0001) with an impact on the overall prevalence of primary CH (from 4.0 to 7.1 per 10,000, p=0.0001). Taking ethnicity into account, the significantly highest primary CH prevalence of 11.3 per 10,000 live births was observed among the Roma neonates, with a predominance of permanent CH (75.5%). There were also regional differences in the prevalence of primary CH. The highest primary CH prevalence of 11.7 per 10,000 live births was observed in the Vardar region, together with the highest regional prevalence of the transient CH (3.2 per 10,000). The highest prevalence of permanent CH was observed in the Pelagonia region (6.6 per 10,000) where the largest percentage of the Roma population lives. The overall CH prevalence is high in North Macedonia, with substantial ethnic and geographical variations. Further analysis to elucidate the causes for the significant variations in the CH prevalence including environmental factors is warranted.

Optimizing Cord Blood Thyroid Stimulating Hormone Cutoff for Screening of Congenital Hypothyroidism-Experience from Screening 164,000 Newborns in a Tertiary Hospital in India.

Background and Objectives:In our institution, we have an ongoing newborn thyroid screening (NBS) program since July 2001. In the initial 9 months, we used cord blood thyroid-stimulating hormone (TSH) (CBTSH) cutoff of 20 mIU/L and thereafter the cutoff was increased to 25 mIU/L. Our objective was to evaluate whether a CBTSH cutoff of 25 mIU/L is sensitive and cost-effective in NBS of congenital hypothyroidism (CH).Materials and Methods:All in-born babies are screened and those with CBTSH ≥25 mIU/L are recalled for confirmatory TSH/T4/FT4 tests. CH is confirmed with elevated TSH and low T4/FT4. Those with CBTSH 20–24.99 mIU/L were recalled for confirmatory tests in initial period of our NBS and prospectively between January and August 2017. Statistical analysis was done to derive positive predictive value and sensitivity to diagnose CH for each CBTSH between 20 and 30 mIU/L.Results:A total of 164,163 neonates were screened from July 2001 to August 2017. Of the 2352 babies with CBTSH ≥25–30 mIU/L, 1763 returned for retesting and 5 confirmed as CH (4 gland-in-situ and 1 absent uptake on nuclear scan). Of the 14,742 screened during the study period, 195 of the 293 babies with CBTSH 20–24.99 mIU/L returned for retesting and none diagnosed as CH. A CBTSH of 25 mIU/L has 99.2% sensitivity and 97.5% specificity. A lower screen TSH cutoff 20 mIU/L would result in recall of additional 300 babies/year with no definite improvement in sensitivity.Conclusions:Our data justify the continuation of using screen TSH cutoff of 25 mIU/L while using cord blood for NBS in our population. With a diverse and large population, it is important that we use feasible regional screen cutoffs for optimal use of our resources.

Aspects of economic costs and evaluation of health surveillance systems after a radiation accident with a focus on an ultrasound thyroid screening programme for children.

Health surveillance initiatives targeted at populations evacuated from, and residing in, areas affected by radiation contamination were implemented by international institutions as well as national and local governments after the nuclear accidents of Chernobyl and Fukushima Dai-ichi nuclear power plants. Most of these initiatives included a component of childhood thyroid cancer monitoring, with the more comprehensive schemes corresponding to national programmes of health monitoring for adults and children around general health and wellbeing. This article provides a short overview of available data on the costs and resources associated with surveillance responses to two recent nuclear accidents: Chernobyl and the Fukushima Dai-Ichi nuclear plant accidents. Moreover, because the balance of costs and benefits of health surveillance after a nuclear accident can influence decisions on implementation, we also present a brief overview of the principles of economic evaluation for collecting and presenting data on costs and outcomes of a surveillance programme after a nuclear accident. We apply these principles in a balance sheet analysis of a post-accident ultrasound thyroid screening programme for children.

Determining the TSH reference range in national newborn screening program for congenital hypothyroidism

Objective: Since the initiation of the thyroid screening program in Iran in 2005, 5 mIU/L has been selected as the threshold for thyroid stimulating hormone (TSH) for screening for congenital hypothyroidism. Given the specific disease pattern in the region and current controversies of the TSH cutoff point, a new cutoff point has been proposed in this study.Methods: This study was conducted on the existing database of the screening program consisting of 127,112 neonates in Markazi Province, center of Iran, during 2006–2012. Data on 614 referred neonates consisting of 414 neonates diagnosed of having hypothyroidism and 200 screened healthy neonates, were analyzed. The heel prick test had been done on the studied neonates to determine the TSH levels. The receiver-operator characteristic (ROC) curve and diagnostic values were used for data analysis.Results: The 5-mIU/L cutoff point in the study had a sensitivity and specificity and AUC of 86.5, 10 and 47%, respectively. Among the eleven selected cutoff points, 6.5 mIU/L had the appropriate sensitivity, specificity and AUC (58.9, 56.5 and 57%, respectively), negative and positive likelihood ratios (0.73 and 1.35, respectively).Conclusion: Given the very low specificity of the 5-mIU/L cutoff point for referral and with respect to the high rate of referrals and many false positive cases, we suggest to use the 6.5-mIU/L cutoff point which is more suitable.

Outcome of thyroid ultrasound screening in FAP patients with a normal baseline exam.

Familial adenomatous polyposis (FAP) is a hereditary cancer syndrome associated with a substantial lifetime risk for colorectal cancer. The leading extra-colonic causes of cancer in FAP include duodenal and thyroid cancer (TC). Recent guidelines recommend annual thyroid ultrasound (TUS) screening beginning in the teenage years but the evidence to support the interval particularly in FAP patients with a normal baseline ultrasound is lacking. TUS results from FAP patients enrolled in a thyroid screening program from 2006 to 2016 and who had at least 2 TUS were reviewed. TUS findings were classified as normal, low (LR) or high risk (HR) for TC based on nodule characteristics as determined by American Thyroid Association (ATA) guidelines. We assessed the incidence of TC in patient with normal baseline TUS and factors associated with TC. 264 FAP patients were included. Baseline TUS was normal in 167, LR in 74, and HR in 24 patients. Patients were observed for a mean 4.8years and underwent an average of 3 TUS. Patients with normal baseline TUS did not develop TC during the course of follow up of 5.1years. TC developed in 6 patients (2.3%) all with baseline nodules; 5 in the LR group and 1 in the HR group. Factors associated with development of TC were presence of baseline nodule(s) and female sex. The development of TC in FAP patients in a TUS screening program with short term follow up is low and no FAP patient with a normal baseline TUS developed TC during observation. Annual TUS in patients with a normal baseline TUS may not be needed. Extending the screening interval to 2years may be reasonable until nodules are detected.

Improving universal newborn hearing screening outcomes by conducting it with thyroid screening

ObjectivesOne of the most important factors that can improve hearing screening indicators is testing infants after 48 h of birth. The neonatal thyroid screening program is done during the third to fifth day after birth in many countries. So this screening is done at the appropriate time for hearing screening. The aim of the present study was to evaluate hearing screening outcomes (the referral rate, false positive rate, and positive predictive value) conducted with the thyroid screening at the healthcare centers and compare the results with hospital before discharge the infant. MethodsThis was a prospective exploratory cohort study. The study population included all the newborns at a hospital (group 1) and newborns who were referred to healthcare centers for thyroid screening (group 2), except for infants with risk factors, from March 2012 to December 2017. Transient evoked otoacoustic emissions (TEOAE) and automatic auditory brainstem response (AABR) were used for the evaluation. The results were compared between the two groups. ResultsOf the 4729 newborns, who participated in the study, 3001 were referred from a hospital (group 1) and 1728 from two healthcare centers (group 2). The referral rate in group 1 and 2 was 16.1% and 7.6%, respectively. Also, the false positive rate in group 1 and 2 was 15.9% and 7.6%, respectively. Our study showed that the referral rate and false positive rate of hearing screening in group 2 were significantly lower than that in group 1 (p < 0.001). The positive predictive value in group 1 was significantly higher than that in group 2 (p < 0.05). There was no significant sex difference in any of the variables. ConclusionsOur results showed that performing the hearing screening during the thyroid program, instead of the hospital could be significantly improved screening outcomes and suggest that hearing and thyroid screening together after discharge from the hospital could be a good opportunity to introduce new framework for hearing screening in many countries.

Screening for neonatal jaundice in El Galaa Teaching Hospital: A Egyptian Maternity Hospital – Can the model be replicated?

Screening for neonatal jaundice may allow early detection and treatment of severe cases and thus help prevent kernictrus. Aim: This pilot study aims to evaluate the effectiveness as well as the practicality of screening for neonatal jaundice at the same time of the Egyptian obligatory thyroid screening program among a sample of non-hospitalized newborns. Subjects and Methods: A population of 3834 term and near-term newborns delivered at El Galaa Teaching Hospital, Cairo, Egypt, was screened for neonatal jaundice at its Maternal Child Health Center within the 1st week of life at the time of thyroid screening (3rd-7th day postnatal). A transcutaneous bilirubinometer (BiliCheck, Respironics, Philips) was used, and bilirubin levels were plotted on the hour-specific bilirubin nomogram. Accordingly, parents were either given a specific date for rescreening or were immediately referred for appropriate intervention. Results: The mean Transcutaneous bilirubin (TcB) measurement was 16.1 mg/dl in 1.9% of the studied newborns placing them in the high-risk zone and requiring immediate referral for serum bilirubin ± phototherapy. In addition, 3.3% of cases had a mean TcB of 14.4 mg/dl (high-intermediate zone) requiring close follow-up. The TcB levels in the remaining babies placed them either in the low or low-intermediate risk zones of the bilirubin nomogram. All babies in the intermediate zone (n = 440) were advised to return for repeat TcB within 48 h. Of 155 babies attending rescreening, 1 case was in the high-risk zone with TcB of 17.2 mg/dl. By the end of the study, 1.2% of all the tested babies had required admission for phototherapy. Conclusion: The already established thyroid screening program offers a golden opportunity for concomitant screening for neonatal jaundice and the detection and management of missed cases of severe hyperbilirubinemia. However the set timing (3-7 days of life) might be quite late for hemolytic cases who develop severe hyperbilirubinemia early.

Thyroid screening in neonates: Indian perspective

Hypothyroidism is most common preventable cause of Mental retardation. Most of developed countries have been adopted neonatal thyroid screening programme three decades back. In India still congenital hypothyroism is important preventable cause of mental retardation. Universal Neonatal thyroid screening looks a distant dream in Indian scenario.

Clinical practice: experience with newborn screening for congenital hypothyroidism in the Republic of Macedonia - a multiethnic country.

To evaluate the thyroid screening program and to estimate the prevalence of congenital hypothyroidism (CH) among newborns in the Republic of Macedonia, we measured thyroid-stimulating hormone (TSH) levels in dried blood spot specimens using the DELFIA fluoroimmunoassay, over a period of 12years. The TSH cutoff level was 10mU/L blood. A total of 215,077 newborns were screened (94.76%). Out of 254 recalled newborns (a recall rate of 0.15%), 83 newborns with CH were detected, yielding a CH prevalence at screening of 1/2,591 (female to male ratio, 1.86:1). Of the CH cases, 47/107,754 (56.6%) neonates were Macedonian, 29/70,330 (34.9%) were Albanian, and 7/15,055 (8.4%) were Roma. The thyroid gland was undetectable on ultrasound in 43 (51.8%) newborns with CH, thyroid hypoplasia was confirmed in 8 (9.6%), while 29 (34.9%) had a normal thyroid gland. In three newborns (3.6%), agenesis of one lobe was confirmed. Therapy with levothyroxin was initiated on average 11.7days after birth. The national thyroid newborn screening program in Macedonia has been successful and effective, providing timely diagnosis and treatment of children with congenital hypothyroidism.

Prevalence of CH that identified in neonatal screening program in Mashhad health center 2011

Introduction: Congenital hypothyroidism is the most common endocrine disease and is a major cause of preventable mental retardation. In most cases, it seems quite natural born at birth with delayed diagnosis, complications will cause irreparable brain. Now almost all industrialized countries and many developing countries the newborn screening program to systematically do. Khorasan Province neonatal hypothyroidism screening using TSH measurements are taken from the heel onto filter paper from the year 2006. Methods: This study is a retrospective study of neonatal screening results are. In a thyroid screening program to inform all mothers through health centers in 3 to 5 days of birth, blood samples on filter paper obtained their heels and the TSH is measured in this study, the results of the 2011 cases were analyzed. Results: Newborn screening of 24,703 cases in 2011, 52% of the infants was girls and 48% boys. Samples in 3 to 5 days, and 30% of the time for various reasons, was later scheduled the 96.9% of normal results (i.e. TSH less than 5), and 3% were suspected (i.e., 5 to 20) and 0.01% positive (i.e. more than 20) have been reported. In positive tests for suspected cases of 4% and a total of 1.3 in a thousand babies have been born with hypothyroidism that the statistics of the prevalence of hypothyroidism (1 in 5000 births) is more. Conclusions: congenital hypothyroidism incidence in the study population in the province 1.3 that the results obtained in births is lower than the national rate (1.7 in a thousand births) is.

Epidemiological studies of Fukushima residents exposed to ionising radiation from theFukushima Daiichi Nuclear Power Plant prefecture—a preliminary review of currentplans

It is now more than six months since the beginning of the accident on 11 March 2011 at theFukushima Daiichi Nuclear Power Plant in Japan. The Japanese government and localhealth authorities have started to collect the information necessary to estimate radiationdoses received by those living in the area around the plant, drafted plans for the healthcare of residents, and started to implement some of them. This paper reviews and discussesthe studies necessary for risk evaluation of cancer and non-cancer diseases, includingthose already planned, mainly from the view point of evaluating health risk usingepidemiological approaches. In the long run, it is important to establish a cohort with acontrol group. Even if the cumulative doses are estimated to be so low that it isdifficult to evaluate the risk of cancer and non-cancer diseases, it is necessary toconduct such a study to reassure residents. The health care programme of theFukushima Prefecture government, including health check-ups of residents, will help toassess indirect effects of radiation exposure, including psychological problems.The success of any studies of radiation epidemiology depends on the collection of accurateinformation on radiation doses received by the study subjects. However, some of thedosimetry surveys were not conducted in a timely manner. (It should be recognised,though, that such a problem might have been inevitable, considering the chaotic conditionafter the nuclear accident.) Accurate estimation of the radiation dose received by eachresident is not only important for scientific risk evaluation but also to inform each residentabout his or her potential risk. Otherwise, residents will bear an undue psychologicalburden from uncertainties regarding their radiation exposure and its health consequences.One of other important tasks in Fukushima is the improvement of the quality of theregional cancer registry in this prefecture. It is also important to start thyroid cancerscreening in a year or two since the expected minimum latent period among thoseexposed in early childhood is about 4 years. Recently, local health authoritiesdecided to start a thyroid screening programme for those aged 18 years or younger.Any scientific efforts in Fukushima, which need to gain the trust of study subjects aboutthe objectivity of research, may suffer from the fact that residents in Fukushima Prefecturehave begun to suspect that the Japanese government and local authorities are keepingimportant information from them. It seems necessary to make more effort to reflect theopinions of residents when planning health care programmes and to gain theunderstanding of the public for the programme. In summary, there are many problemsthat make the evaluation of cancer and non-cancer disease risk in Fukushimadifficult. The help of international colleagues will be invaluable for overcoming thoseproblems. In this paper, these efforts are briefly summarised and some comments aremade.

Primary blood TSH/back up TSH measurements: an improved approach for neonatal thyroid screening

Neonatal hypothyroidism is one of the most common endocrine disorders related to mental impairment and growth retardation in newborns. In many countries, the neonatal thyroid screening programs are performed for rapid diagnosis and treatment of hypothyroidism. The major aim of this investigation was to improve the thyroid screening program using primary blood TSH/back up TSH measurements as some patients are missed due to technical and human errors. A total of 9,118 neonates were evaluated on the protocol. On top of that, the quality control procedures were applied to improve the sampling technique and the laboratory results. Three missed neonates by current programs using the cutoff point more than 20 mU/l for blood TSH were found by our approach. Results showed that the programs based on the primary blood TSH/back up TSH measurements improve the thyroid screening results.

Is Umbilical Cord Blood Total Thyroxin Measurement Effective in Newborn Screening for Hypothyroidism?

To assess the performance of the use of umbilical cord blood for screening of primary congenital hypothyroidism in the Saudi Aramco Medical Services Organization newborn thyroid screening programme. Umbilical cord blood total thyroxin (CB-TT4) was measured. In samples with low T4 concentrations, an additional measurement of cord blood thyroid-stimulating hormone was made. A total of 96,015 newborn infants were screened in the period January 1990-December 2007. Twenty-six cases of primary congenital hypothyroidism, six cases of transient hypothyroidism and 13 cases of central hypothyroidism were detected. This method of screening resulted in 100% sensitivity and 98% specificity (95% CI 84-100, and 95% CI 98-98.2, respectively). However, there was a high mean recall rate of 1.9%. The use of CB-TT4 is a valid screening strategy for primary congenital hypothyroidism. It meets the metabolic screening demands of early discharge policy and guarantees screening all newborns delivered in the hospital.

Epidemiology of congenital hypothyroidism.

According to world-wide data obtained from neonatal thyroid screening programs congenital hypothyroidism (CH) occurs with an incidence of 1:3000 to 1:4000. Differences of CH-incidence are more likely due to iodine deficiency thyroid disorders or to the type of screening method than to ethnic affiliation. CH is caused by an absent or defective thyroid gland classified into agenesis (22-42%), ectopy (35-42%) and gland in place defects (24-36%). Although a few cases of thyroid dysgenesis have been described as a result of gene mutations, there is no common link to explain the etiological background of the majority of cases. Neonatal screening is severely affected by iodine deficiency leading to an increasing rate of false positive, transient and permanent cases of CH. Despite of low T4 and T3 levels the majority of low-birth-weight infants are not at risk of transient hypothyroidism. Neonatal screening in early discharged neonates mostly is not recommended before day 4. Since the intellectual outcome of CH seems below normal in Germany a CH registry and monitoring program on a national basis is recommended.

Is Thyroid Screening Necessary for Nuclear Medicine Personnel Receiving and Administering Capsules Containing Large Doses of 131I?

The cost-effectiveness of a thyroid screening procedure for the detection of internal contamination of personnel working with large doses of encapsulated iodine-131 ( 131I) was examined by reviewing the results of screening measurements performed during 1 year. Thyroid burdens were measured by self-assessment using a sodium iodide (NaI) probe. Of 113 screening measurements, 101 indicated a negative thyroid content of 131I. The largest burden observed was statistically not different from zero. The count rate corresponding to the largest observed burden would represent an 131I content of 23 Bq, which is approximately 0.2% of the level at which results have to be reported to the Canadian Nuclear Safety Commission. Negative count rates arose because of a small overestimation of the background contribution that was measured with a neck phantom positioned in front of the thyroid probe. The cost of a thyroid screening program for personnel who handle encapsulated 131I is considerable, especially when the need for such measurements is questionable.

Thyroid insufficiency during pregnancy: complications and implications for screening

In 2007, clinical practice guidelines concerning the management of thyroid dysfunction during pregnancy and postpartum were published in the Journal of Clinical Endocrinology and Metabolism. They were elaborated on by a panel of experts, representative of the Latin American Thyroid Society, the Asia and Oceania Thyroid Society, the American Thyroid Association, the European Thyroid Association, the American Association of Clinical Endocrinologists and the Endocrine Society. In women not known to have thyroid dysfunction, universal screening during pregnancy is not recommended, but thyroid function tests are advised in those with prior therapeutic head or neck irradiation, a history of preterm delivery, in cases of infertility and in the presence of risk factors for thyroid disease. Risks factors for thyroid dysfunction are considered as a personal or family history of thyroid diseases, presence of thyroid antibodies (when known), personal history of autoimmune diseases and the presence of signs or symptoms suggesting hypo- or hyperthyroidism. In this review, we summarize the modifications of the pituitary–thyroid axis during pregnancy, with particular attention on thyroid insufficiency. We consider the most important risk factors for thyroid dysfunction and focus our attention on the complications for the progeny, deriving from a condition of maternal thyroid impairment. We will discuss the matters in favor of or against a thyroid-screening program at the beginning of pregnancy.

The effect of the mode of delivery on neonatal thyroid function

Background. We aimed to investigate the effect of the mode of delivery and the type of anesthesia on postnatal thyroxine (T4), free T4 (f-T4) and thyroid-stimulating hormone (TSH) in a large number of healthy full-term neonates.Methods. Serum samples for T4, TSH and f-T4 were drawn from neonates at the time of discharge (postnatal days 1–7) in a pilot thyroid-screening program. Six hundred and thirty-eight neonates were grouped as: vaginal delivery (VD; 332), elective cesarean section (elective C/S; 252) and emergency cesarean section (emergency C/S; 54). The elective C/S group was subdivided into local and general anesthesia groups to investigate the influence of the type of anesthesia used on thyroid function.Results. Mean±SD serum T4, TSH and f-T4 levels tended to be higher in the VD group compared to the elective C/S group at almost all time points. However the differences did not reach statistical significance, except for the T4 levels at postnatal day 3 in the VD group, which was higher (195.6±37.3 nmol/L) compared to the elective C/S group (160.9±34.8 nmol/L) (p < 0.001). The only difference in the anesthesia groups was the slightly higher f-T4 levels from postnatal day 4 in the local anesthesia group compared to the general anesthesia group.Conclusions. The mode of delivery or type of anesthesia does not have considerable influence on postnatal thyroid functions in the neonates, although minor differences exist. Therefore similar cut-off values can be used for thyroid screening of term newborns regardless of the mode of delivery or type of anesthesia used.

A review of the case for neonatal thyrotropin screening in developing countries: the example of India.

Infantile hypothyroidism, either caused by iodine-deficiency disorder (IDD) or congenital hypothyroidism (CH), is the world's leading cause of preventable mental retardation. Such hypothyroidism has virtually been eliminated in the developed world by salt iodization and neonatal thyroid screening. However, most developing countries do not have neonatal thyroid screening programs. Using India as an example, we review the case for newborn screening in the developing world. A literature review on infantile hypothyroidism in India was conducted and three Indian thyroid experts were queried about their views on neonatal screening in India. Iodine nutrition improved markedly in India during the 1990s; 49% of the households are now using adequately iodized salt. The control of IDD is still insufficient in India. Nationally representative data on neonatal screening in India are not available, but two regional studies have been published. One study (n = 12,407) measured cord blood thyrotropin and the other (n = 25,244) measured filter paper thyroxine. These studies reported difficult socioeconomic and organizational barriers to the implementation of neonatal screening in India. It is time for India to make neonatal thyroid screening and mandatory iodization of salt a priority and develop a comprehensive infantile hypothyroidism policy. Prioritization of infantile hypothyroidism prevention is justified by its high frequency, sensitivity of screening in detecting both IDD and CH, adverse consequences of missing diagnosis at birth, high effectiveness of prevention, severity of disability from hypothyroidism, cost effectiveness of prevention, and lack of a clinical method of diagnosis near birth.

Potential Pitfalls in Screening Programs for Congenital Hypothyroidism

After completing this article, readers should be able to: 1. Delineate situations in which blood specimens for screening may be overlooked. 2. Describe the patterns of thyroid-stimulating hormone and thyroxine concentrations in very low-birthweight infants and the implications of these patterns for thyroid screening programs. For those of us involved in newborn screening, there is nothing more devastating than learning that the program did not detect an infant who has congenital hypothyroidism. After a moment of disbelief, we ask, “How did this happen and what should or could have been done to prevent such tragedy?” Moreover, in the typical scenario the misfortune frequently is compounded by failure of the clinician to make the clinical diagnosis in a timely fashion. Although these events are rare (probably less than one birth in 1 million), they should not be taken lightly. For the pediatrician, knowing where potential pitfalls lie might spare some future family from the needless anguish of a missed diagnosis. Slightly more than one quarter of a century ago a report emanating from Canada described a procedure for the measurement of thyroxine (T4) in dried blood on filter paper, opening the way for early detection and treatment of infants who have congenital hypothyroidism. Within a relatively short period of time, newborn screening programs for congenital hypothyroidism emerged in most of the industrialized nations, thereby relegating a major scourge of society to the status of a medical curiosity. At the outset, most screening programs were relatively primitive, lacking sophisticated data management systems and beset with technical and logistical problems. However, the manufacture of reliable assay materials and the introduction of automation coupled with online data reduction eventually improved these programs. Such improvements, together with growing experience in interpretating test results, overcame many of the drawbacks associated with early screening programs. Although most (but not …