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Thyroid Dysfunction and the Effect of Iodine-Deficient Parenteral Nutrition in Very Low Birth Weight Infants: A Nationwide Analysis of a Korean Neonatal Network Database. Nutrients 2022; 14:nu14153043. [PMID: 35893897 PMCID: PMC9331788 DOI: 10.3390/nu14153043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/20/2022] [Accepted: 07/23/2022] [Indexed: 11/30/2022] Open
Abstract
Background: To investigate the impact of nutritional iodine deficiency on thyroid dysfunction (TD) in very low birth weight (VLBW) infants, we analyzed the association between iodine-deficient parenteral nutrition (PN) and TD requiring L-thyroxine (TD-LT4). Methods: Data of VLBW infants were obtained from the Korean Neonatal Network registry. Factors including duration of PN were analyzed according to TD-LT4. Results: TD-LT4 occurred in 490 (8.7%) of 5635 infants, and more frequently occurred in infants requiring PN for ≥4 weeks (10.2%). PN ≥ 4 weeks was one of the risk factors for TD-LT4, with an odds ratio (OR) of 1.346, p = 0.002. However, multivariate analysis showed that TD-LT4 was more of a risk for infants that were small for gestational age (OR 2.987, p < 0.001) and for other neonatal morbidities such as seizures (OR 1.787, p = 0.002) and persistent pulmonary hypertension (OR 1.501, p = 0.039) than PN ≥ 4 weeks (OR 0.791, p = 0.080). Conclusions: Prolonged iodine-deficient PN might affect TD-LT4 in VLBW infants. However, the effect of nutritional iodine deficiency on TD-LT4 risk was less than that of SGA or severe neonatal morbidities in Korean VLBW infants.
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Rose SR, Blunden CE, Jarrett OO, Kaplan K, Caravantes R, Akinbi HT. Utility of Repeat Testing for Congenital Hypothyroidism in Infants with Very Low Birth Weight. J Pediatr 2022; 242:152-158.e1. [PMID: 34748741 PMCID: PMC8882159 DOI: 10.1016/j.jpeds.2021.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/01/2021] [Accepted: 11/01/2021] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To assess for possible missed hypothyroidism in infants of very low birth weight (VLBW) whose initial newborn screening (NBS) was within normal reference range. STUDY DESIGN We analyzed serum thyroid-stimulating hormone (TSH) obtained at 36 weeks of corrected gestational age or at hospital discharge if earlier (retest TSH) in infants with VLBW in the neonatal intensive care unit to determine the prevalence and factors associated with retest TSH ≥5 mU/L, a concentration requiring close follow-up for hypothyroidism. Utility of alternative cut-offs for NBS TSH also was assessed. RESULTS A total of 398 infants, median gestational age 29 (range 22-36) weeks, birth weight 1138 (470-1498) g, were included in this study. Retest TSH was obtained at 49.5 (12-137) days after birth. Median retest TSH was 3.1 (0.5-27.9) mU/L. Seventy-three (18.3%) of the cohort had retest TSH ≥5 mU/L. Adjusting NBS cut-off to ≥15 or ≥10 mU/L identified <50% of infants with TSH ≥5 mU/L, resulting in 6% false positives and >70% false negatives. Multiple regression modeling indicated that 35% of variance in retest TSH value was explained by NBS TSH concentration, birth weight, and gestational age, all P < .01. CONCLUSIONS Retesting for hypothyroidism at 36 weeks of corrected gestational age in infants with VLBL and normal NBS could identify infants who require ongoing surveillance until thyroid function has been definitively ascertained. Adjusting NBS TSH cutoffs is not a valid option for identifying potential hypothyroidism in infants with VLBW because of lack of sensitivity and unacceptable false-positive and false-negative rates.
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Affiliation(s)
- Susan R Rose
- Division of Endocrinology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Christopher E Blunden
- Division of Endocrinology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH; Children's Hospital of Michigan, Detroit Medical Center, Detroit, MI
| | - Olumide O Jarrett
- Global Health Center, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH; University College Hospital, Ibadan, Nigeria
| | - Kyle Kaplan
- James M Anderson Center for Health Systems Excellence, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH
| | | | - Henry T Akinbi
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH; Perinatal Institute, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH.
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Cortez AB, Lin B, May JA. Targeted Secondary Screening for Congenital Hypothyroidism in High-Risk Neonates: A 9 Year Review in a Large California Health Care System. Int J Neonatal Screen 2021; 7:81. [PMID: 34940051 PMCID: PMC8703346 DOI: 10.3390/ijns7040081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 11/16/2022] Open
Abstract
Secondary screening for missed congenital hypothyroidism (CH) has been introduced sporadically, but its necessity and optimal strategy have not been recognized. We hypothesized that a simple clinical protocol (performed by a medical group without a governmental mandate) targeting infants at high risk for missed CH can identify cases. We performed a 9-year retrospective review of 338,478 neonates within a California health plan following the introduction of thyrotropin (TSH) secondary screening for neonates at high risk for missed CH due to very-low-birthweight (VLBW), hospitalized congenital heart disease (CHD), and same-sex multiples (SSM). Screening performance by day 60 of life was 95% successful for VLBW and >50% for CHD and SSM, leading to an additional 35% CH treated cases despite re-testing only 1.7% of the cohort. Infants with VLBW or CHD were 33 times more likely (190 times more likely for CHD with Down Syndrome) to receive treatment for CH than random infants diagnosed by primary screening (p < 0.001), and 92% of these infants were not found by primary newborn screening. Currently, permanent disease has been documented in 84% of CH by primary screening compared to 27% by secondary screening (p < 0.001). This targeted secondary screening program identifies and treats additional CH cases after TSH-only newborn screening.
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Affiliation(s)
- Alan B. Cortez
- Southern California Permanente Medical Group, Department of Pediatrics, Pediatric Endocrinology, Tustin, CA 92780, USA;
| | - Bryan Lin
- Kaiser Permanente Department of Research, Pasadena, CA 91188, USA;
| | - Joshua A. May
- Southern California Permanente Medical Group, Department of Pediatrics, Pediatric Endocrinology, Los Angeles, CA 90027, USA
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Utility of the New Indian Society of Paediatric and Adolescent Endocrinology (ISPAE) Guidelines for Congenital Hypothyroidism Screening in a High Risk Unit. Indian J Pediatr 2021; 88:1075-1079. [PMID: 33215310 DOI: 10.1007/s12098-020-03555-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/22/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To study the new ISPAE guidelines in neonates with congenital hypothyroidism and present authors' experience in managing these neonates. METHODS A retrospective review of all babies who were screened for congenital hypothyroidism in the institution over a period of 5 y was conducted. Details pertaining to maternal risk factors, neonatal risk factors, screening TSH, venous TSH and details of etiological evaluation including: ultrasound thyroid, technetium 99m scintigraphy and anti thyroid peroxidase antibody estimation were retrieved. The cases were assessed using the new ISPAE guidelines. RESULTS During the study period, 8107 babies were screened for congenital hypothyroidism, 83 cases had confirmed disease and 47 had established etiology. There is a fair correlation between screening TSH and venous TSH (r = 0.7, p < 0.05). The estimated incidence of congenital hypothyroidism in present series is 1 in 97 cases. Out of the 83 cases, 36 (43.3%), 16 (19.2%) and 31 (37.3%) cases had screening TSH >20 μIU/mL, 6-20 μIU/mL and < 6 μIU/mL, respectively. Out of the 47 babies with screening TSH <20 μIU/mL, 23 (48.9%), 25 (53.1%) and 12 (25.5%) cases had prematurity, maternal thyroid disease and illness, respectively, as risk factors (some babies had more than one risk factor). Of the 83 cases, all of them had venous TSH >10 μIU/mL and five cases had low Free T4 (<1.1 ng/dl). Thus, none of the cases with congenital hypothyroidism were missed on the new ISPAE guidelines. CONCLUSION The new ISPAE guidelines for neonatal screening for congenital hypothyroidism are very useful and applicable in Indian neonates.
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Hashemipour M, Hovsepian S, Ansari A, Keikha M, Khalighinejad P, Niknam N. Screening of congenital hypothyroidism in preterm, low birth weight and very low birth weight neonates: A systematic review. Pediatr Neonatol 2018; 59:3-14. [PMID: 28811156 DOI: 10.1016/j.pedneo.2017.04.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 01/09/2017] [Accepted: 04/12/2017] [Indexed: 11/30/2022] Open
Abstract
Evidence from different screening programs indicated that the rate of congenital hypothyroidism (CH) was higher in pre-term and low-birth-weight (LBW) newborns than normal ones. Incomplete development of hypothalamic-pituitary axis in this group of neonates results in the delayed rise of TSH and missing cases with CH. Hence, there is a great need for a practicable systematic screening method for proper diagnosis of CH in this group of neonates. In this review, we systematically reviewed papers with the following key words ([Congenital Hypothyroidism AND Screening AND Thyroxine AND Thyroid Stimulating Hormone AND Low Birth Weight AND Premature]) in international electronic databases including PubMed, Scopus, and Google Scholar. After quality assessment of selected documents, data of finally included papers were extracted. In this review, 1452 papers (PubMed: 617; Scopus: 714; Google scholar: 121) were identified through electronic database search. One hundred and ninety four articles were assessed for eligibility, from which 36 qualified articles were selected for final evaluation. From the reviewed articles, 38.9%, 11.11% and 8.3% recommended rescreening in this group of neonates, lowering the screening cutoff of TSH and using cutoffs according to the gestational age, respectively. Some of them (13.9%) recommended using both TSH and T4 for screening of preterm infants. After reviewing available data, we recommend repeating the screening test in pre-term, LBW and very-low- birth-weight (VLBW) infants at age of two, six and ten weeks by measuring TSH and FT4 levels simultaneously and considering TSH = 10 mU/L as the cutoff level for positive and suspicious cases.
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Affiliation(s)
- Mahin Hashemipour
- Isfahan Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Pediatrics, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Emam Hossein Children's Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Silva Hovsepian
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Arman Ansari
- Students Research Committee, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mojtaba Keikha
- Department of Epidemiology, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Pooyan Khalighinejad
- Students Research Committee, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Negar Niknam
- Students Research Committee, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Lee JH, Kim SW, Jeon GW, Sin JB. Thyroid dysfunction in very low birth weight preterm infants. KOREAN JOURNAL OF PEDIATRICS 2015. [PMID: 26213551 PMCID: PMC4510356 DOI: 10.3345/kjp.2015.58.6.224] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Thyroid dysfunction is common in preterm infants. Congenital hypothyroidism causes neurodevelopmental impairment, which is preventable if properly treated. This study was conducted to describe the characteristics of thyroid dysfunction in very low birth weight infants (VLBWIs), evaluate risk factors of hypothyroidism, and suggest the reassessment of thyroid function with an initially normal thyroid-stimulating hormone (TSH) as part of a newborn screening test. METHODS VLBWIs (January 2010 to December 2012) were divided into two groups according to dysfunction-specific thyroid hormone replacement therapy, and associated factors were evaluated. RESULTS Of VLBWIs, 246 survivors were enrolled. Only 12.2% (30/246) of enrolled subjects exhibited thyroid dysfunction requiring thyroid hormone replacement. Moreover, only one out of 30 subjects who required thyroid hormone treatment had abnormal thyroid function in the newborn screening test with measured TSH. Most of the subjects in the treatment group (22/30) exhibited delayed TSH elevation. Gestational age, Apgar score, antenatal steroids therapy, respiratory distress syndrome, patent ductus arteriosus, sepsis, intraventricular hemorrhage, postnatal steroids therapy, and duration of mechanical ventilation did not differ between the two groups. Birth weight was smaller and infants with small for gestational age were more frequent in the treatment group. CONCLUSION Physicians should not rule out suggested hypothyroidism, even when thyroid function of a newborn screening test is normal. We suggest retesting TSH and free thyroxine in high risk preterm infants with an initially normal TSH level using a newborn screening test.
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Affiliation(s)
- Ji Hoon Lee
- Department of Pediatrics, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Sung Woo Kim
- Department of Pediatrics, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Ga Won Jeon
- Department of Pediatrics, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Jong Beom Sin
- Department of Pediatrics, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
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Lim G, Lee YK, Han HS. Early discontinuation of thyroxine therapy is possible in most very low-birthweight infants with hypothyroidism detected by screening. Acta Paediatr 2014; 103:e123-9. [PMID: 24117608 DOI: 10.1111/apa.12450] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 09/08/2013] [Accepted: 10/01/2013] [Indexed: 11/30/2022]
Abstract
AIM To determine the feasibility of discontinuing thyroid hormone treatment earlier than recommended by the current guidelines for congenital hypothyroidism. METHODS We retrospectively reviewed the medical records of very low-birthweight (VLBW) infants born at Chungbuk National University Hospital from January 2006 to December 2010. Infants were divided into two groups--hypothyroid and normal thyroid--on the basis of the thyroid function test results. Infants in the hypothyroid group were treated with levothyroxine (L-T4) and attempts to discontinue this therapy began when they were about 2 years old. RESULTS Of the 216 infants born during the study period, 20 died and 196 were included in the study. Of these, 46 were in the hypothyroid group and 150 were in the normal thyroid group. Thirty-nine infants were taken off L-T4 therapy at around 2 years of age. All were successfully weaned off L-T4 and retained normal thyroid function. Tc-99 m thyroid scans were performed in 32 infants, and no distinct abnormality was noted. CONCLUSION Thyroid dysfunction in VLBW infants was common in our cohort and most cases were transient. Attempts to discontinue this therapy could begin at around the age of two or earlier when low doses of L-T4 have achieved maintenance.
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Affiliation(s)
- Gina Lim
- Department of Pediatrics; Ulsan University Hospital; University of Ulsan College of Medicine; Ulsan Korea
| | - Youn Kyung Lee
- Department of Pediatrics; Chungbuk National University Hospital; Cheongju Korea
| | - Heon-Seok Han
- Department of Pediatrics; Chungbuk National University Hospital; Cheongju Korea
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Korzeniewski SJ, Kleyn M, Young WI, Chaiworapongsa T, Schwartz AG, Romero R. Screening for congenital hypothyroidism in newborns transferred to neonatal intensive care. Arch Dis Child Fetal Neonatal Ed 2013; 98. [PMID: 23183553 PMCID: PMC4136805 DOI: 10.1136/archdischild-2012-302192] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To evaluate the effectiveness of four dried blood spot testing protocols used in newborn screening for congenital hypothyroidism (CH) among newborns transferred to the neonatal intensive care unit (NICU). DESIGN, SETTING AND PATIENTS Michigan newborns transferred to the NICU from 1998 to 2011 and screened for CH are included in this population-based retrospective cohort study. MAIN OUTCOME MEASURES Screening performance metrics are computed and logistic regression is used to test for differences in the likelihood of detection across four periods characterised by different testing protocols. RESULTS Primary thyrotropin (TSH) plus retest at 30 days of life or discharge achieved the greatest detection rate (2.6: 1000 births screened). The odds of detection was also significantly greater in this period compared with the tandem thyroxine (T4) and TSH testing period and separately compared with TSH testing alone, adjusted for birth weight, sex and race (OR 1.5; CI 1.0 to 2.2; p=0.046, and OR 2.2; CI 1.5 to 3.4, respectively). Approximately half of the cases detected during primary TSH plus serial testing periods were identified by retest. CONCLUSIONS Primary TSH testing programmes that do not incorporate serial screening may fail to identify approximately half of newborns with congenital thyroid hormone deficiency transferred to the NICU. Tandem T4 and TSH testing programmes also likely miss cases who otherwise would receive treatment if serial testing were conducted. Further research is necessary to determine the optimal newborn screening protocol for CH; strategies combining tandem T4 and TSH with serial testing conditional on birthweight may be useful.
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Affiliation(s)
- Steven J. Korzeniewski
- Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA,Corresponding Author: Steven J. Korzeniewski, Director, Perinatal Epidemiology Unit, Perinatology Research Branch, NICHD/NIH/DHHS, Assistant Professor, Department of Obstetrics & Gynecology, Wayne State University School of Medicine, Hutzel Women's Hospital, 4 Brush - Office 4817, 3990 John R. - Detroit, MI 48201, P 313.577.0364~ F 313.577.5242,
| | - Mary Kleyn
- Michigan Department of Community Health, Lansing, MI, USA
| | | | - Tinnakorn Chaiworapongsa
- Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA
| | | | - Roberto Romero
- Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA
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Korzeniewski SJ, Grigorescu V, Kleyn M, Young W, Birbeck GL, Todem D, Romero R, Chaiworapongsa T, Paneth N. Performance metrics after changes in screening protocol for congenital hypothyroidism. Pediatrics 2012; 130:e1252-60. [PMID: 23045555 PMCID: PMC3483888 DOI: 10.1542/peds.2011-3340] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE To evaluate Michigan newborn screening for congenital hypothyroidism (CH) protocol changes. METHODS This population-based study includes infants born and screened in Michigan (January 1, 1994-June 30, 2010). Screening performance is compared across 4 periods defined by the dried blood spot testing method: (1) thyroxine (T4) with backup thyrotropin, (2) tandem T4 and thyrotropin, (3) primary thyrotropin testing without serial testing, and (4) primary thyrotropin plus serial testing for births weighing <1800 g. Logistic regression is used to test for differences across periods. RESULTS Thyrotropin testing exhibited greater specificity overall and greater likelihood of detection with serial testing relative to primary T4 testing. Tandem T4 and thyrotropin testing appeared more sensitive relative to other protocols, yet it produced significantly more false-positives, and detection may have been affected by overdiagnosis and misclassification. Central CH was no longer detected once T4 testing ceased. CONCLUSIONS Primary thyrotropin plus serial testing for infants at risk for later rising thyrotropin outperformed other newborn screening strategies for classic CH, although 2 false-negatives occurred among normal birth weight infants admitted to the NICU during this testing period. Tandem T4 and thyrotropin screening outperformed other strategies for detection of both classic and central CH combined, although it is associated with increased operating costs. Additional research is necessary to weigh the benefits of increased sensitivity against additional program operating costs.
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Affiliation(s)
- Steven J. Korzeniewski
- Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Detroit, Michigan;,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan
| | | | - Mary Kleyn
- Michigan Department of Community Health, Lansing, Michigan; and
| | - William Young
- Michigan Department of Community Health, Lansing, Michigan; and
| | - Gretchen L. Birbeck
- Department of Epidemiology, Michigan State University, East Lansing, Michigan
| | - David Todem
- Department of Epidemiology, Michigan State University, East Lansing, Michigan
| | - Roberto Romero
- Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Detroit, Michigan
| | - Tinnakorn Chaiworapongsa
- Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Detroit, Michigan;,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan
| | - Nigel Paneth
- Department of Epidemiology, Michigan State University, East Lansing, Michigan
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Bijarnia S, Wilcken B, Wiley VC. Newborn screening for congenital hypothyroidism in very-low-birth-weight babies: the need for a second test. J Inherit Metab Dis 2011; 34:827-33. [PMID: 21331666 DOI: 10.1007/s10545-011-9286-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Revised: 01/12/2011] [Accepted: 01/24/2011] [Indexed: 10/18/2022]
Abstract
BACKGROUND Very-low-birth-weight babies (VLBW) with hypothyroidism may show a delayed postnatal rise in thyroid stimulating hormone (TSH), mainly due to immaturity of the hypothalamic-pituitary-thyroid axis. Transient hypothyroidism is prevalent in VLBW babies and some affected babies are considered to need treatment. There is disagreement about whether a second screening test is needed in VLBW babies to detect all cases that need treatment. METHODS We included in the study all babies with a birth weight ≤ 1,500 g born in New South Wales and the Australian Capital Territory between January 2006 and December 2008. Newborn screening samples for TSH measurement were taken in the first days of life and again at 1 month. During week 1, a blood-spot TSH level of ≥20 mIU/L was considered positive, and at 1 month a positive level was ≥7 mIU/L, and triggered full investigation. RESULTS In the cohort of 301,000 babies, 2,313 VLBW babies survived for testing, and 2,117 repeat screening samples were received. Forty-three babies had transient hypothyroidism, with thyroid function normalising before 2 months of age, usually without treatment. Eighteen babies required treatment beyond 2 months of age (1:128 of surviving babies), 16 having had normal TSH results on initial testing, and 12 having levels below 6 mIU/L. CONCLUSION Significant hypothyroidism, transient or permanent, but persisting beyond 2 months of age is common in VLBW babies. There is a delayed rise in TSH in some, and secondary screening at 1 month of age detects babies deemed by local paediatric endocrinologists as needing treatment.
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Affiliation(s)
- Sunita Bijarnia
- The Children's Hospital at Westmead, Westmead, NSW, Australia.
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Najafi M, Farsi MM, Sabahi M. Primary blood TSH/back up TSH measurements: an improved approach for neonatal thyroid screening. J Clin Lab Anal 2011; 25:61-3. [PMID: 21254245 DOI: 10.1002/jcla.20431] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE 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. METHODS 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. RESULTS Three missed neonates by current programs using the cutoff point more than 20 mU/l for blood TSH were found by our approach. CONCLUSION Results showed that the programs based on the primary blood TSH/back up TSH measurements improve the thyroid screening results.
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Affiliation(s)
- Mohammad Najafi
- Biochemistry Department, Cellular and Molecular Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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