Neonatal screening for congenital hypothyroidism in the Federation of Bosnia and Herzegovina: eight years' experience

Worldwide Recall Rate in Newborn Screening Programs for Congenital Hypothyroidism

CONTEXT

Neonatal mass screening program for congenital hypothyroidism provides the best tool for prevention of its devastating effects on mental development. Despite the overall success of the screening programs in detecting congenital hypothyroidism and eliminating its sequelae and new developments made in the program design, high recall rate and false positive results impose a great challenge worldwide. Lower recall rate and false positive results may properly organize project expenses by reducing the unnecessary repeated laboratory tests, increase physicians and parents' assurance and cooperation, as well as reduce the psychological effects in families.

EVIDENCE ACQUISITION

In this review, we assessed the recall rate in different programs and its risk factors worldwide.

METHODS

Publications reporting the results of the CH screening program from 1997 to 2016 focusing on the recall rate have been searched.

RESULTS

Recall rates vary from 0.01% to 13.3% in different programs; this wide range may be due to different protocols of screening (use of T4 or TSH or both), different laboratory techniques, site of sample collection, recall cutoff, iodine status, human error, and even CH incidence as affected by social, cultural, and regional factors of the population.

CONCLUSIONS

It is suggested to implement suitable interventions to reduce the contributing factors by improving the quality of laboratory tests, selecting conservative cut off points, control iodine deficiency, use of iodine free antiseptic during delivery, and use of more specific markers or molecular tests. Applying an age dependent criteria for thyrotropin levels can be helpful in regions with a varied time of discharge after delivery or for preterm babies.

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.

Current status of newborn screening worldwide: 2015

Newborn screening describes various tests that can occur during the first few hours or days of a newborn's life and have the potential for preventing severe health problems, including death. Newborn screening has evolved from a simple blood or urine screening test to a more comprehensive and complex screening system capable of detecting over 50 different conditions. While a number of papers have described various newborn screening activities around the world, including a series of papers in 2007, a comprehensive review of ongoing activities since that time has not been published. In this report, we divide the world into 5 regions (North America, Europe, Middle East and North Africa, Latin America, and Asia Pacific), assessing the current NBS situation in each region and reviewing activities that have taken place in recent years. We have also provided an extensive reference listing and summary of NBS and health data in tabular form.

Newborn screening in southeastern Europe

The aim of our study was to assess the current state of newborn screening (NBS) in the region of southeastern Europe, as an example of a developing region, focusing also on future plans. Responses were obtained from 11 countries. Phenylketonuria screening was not introduced in four of 11 countries, while congenital hypothyroidism screening was not introduced in three of them; extended NBS programs were non-existent. The primary challenges were identified. Implementation of NBS to developing countries worldwide should be considered as a priority.

[Newborn Screening Program for congenital hypothyroidism of the State of Santa Catarina, Brazil: etiological investigation in the first visit]

OBJECTIVE

To evaluate the etiology of primary congenital hypothyroidism (PCH) identified in the Newborn Screening Program from the state of Santa Catarina, Brazil, from July 2007 to June 2009 in the first visit.

SUBJECTS AND METHODS

A prospective study was performed in 45 patients with PCH. For the etiological diagnosis, history, physical examination, and additional tests (TSH, free thyroxine, thyroglobulin, bone age assessment, thyroid ultrasound) were carried out in the first visit.

RESULTS

The etiology was established in the first visit in 53.3% of cases. Thyroid dysgenesis represented 51.11% of the cases, from which 20% showed hypoplastic thyroid, 13.3% showed athyreosis, and 17.7% showed ectopic glands; 2.2% were diagnosed with dyshormonogenesis. Umbilical hernia was the most prevalent sign (48.89%) and 20% had no clinical manifestations. Patients with dysgenesis showed significant differences (p < 0.05) in terms of cesarean section delivery, delayed bone age, and very high serum TSH.

CONCLUSIONS

The diagnostic approach used at first visit for PCH patients may determine the etiology in 53.3% of cases. Half of patients had thyroid dysgenesis.

Maternal and neonatal urinary iodine excretion and neonatal TSH in relation to use of antiseptic during caesarean section in an iodine sufficient area

AIM

To evaluate the influence of topical iodine-containing antiseptics on neonatal TSH in full-term infants born by Caesarean section in an iodine sufficient area.

POPULATION AND METHODS

Urinary iodide excretion (UIE) was estimated in 86 mothers on the second day after delivery by Caesarean section and their 86 full-term neonates. The mothers were divided into two groups according to the use of antiseptic to prepare Cesarean sections: 42 mothers who were prepared with povidone-iodine (Isosept, Bosnalijek) comprised the study group, and 47 mothers who were prepared with alcoholic solution (Skinsept color, Ecolab) formed the control group. Neonatal TSH was measured in whole blood drawn between day 3 and 5 of life, spotted on filter paper using a sensitive fluorometric assay (Delfia).

RESULTS

Maternal and neonatal UIE were significantly higher (p < 0.05) in the study group compared to the control group. No significant difference was found for neonatal TSH.

CONCLUSION

Our data suggest that perinatal iodine exposure of full-term neonates who were born by Caesarean section in an iodine sufficient area did not influence neonatal TSH, although median UIE was higher, suggesting optimal iodine intake during pregnancy. Further research is needed to define a critical value of urinary iodine concentrations in full-term neonates in an iodine sufficient area that may lead to the impairment of thyroid function.