Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 May 6:40:e2020376.
doi: 10.1590/1984-0462/2022/40/2020376IN. eCollection 2022.

A suggested screening method for hypothyroidism in very preterm and/or very low birth weight neonates

[Article in English, Portuguese]
Kayvan Mirnia  1 , Sina Dindarian  2 , Sedra Mohammadi  2 , Parastoo Rostami  1 , Hozan Mohammadi  3
Affiliations

A suggested screening method for hypothyroidism in very preterm and/or very low birth weight neonates

[Article in English, Portuguese]
Kayvan Mirnia et al. Rev Paul Pediatr. .

Abstract
in English, Portuguese

Objective: To assess thyroid function in very preterm or very low birth weight (VLBW) neonates by measuring combination levels of thyroid-stimulating hormone TSH and free T4 (FT4).

Methods: Inclusion criteria were defined as all very preterm (gestational age <32 weeks) or VLBW (birth weight ≤1500g) neonates with initial Thyroid Function Test (TFT) who were admitted to the Neonatal Intense Care Unit (NICU) of Taleghani Hospital, Tabriz, Iran, from March 2015 to March 2016. Exclusion criteria were the absence of initial TFT with any major congenital anomaly. The primary value of TSH was evaluated at 3-5 days, and mean levels of TSH with FT4 were measured at 2, 4, and 8-weeks.

Results: Ninety-five neonates with a mean gestational age of 29.5 weeks were included, and the mean levels of thyrotropin and FT4 at postnatal week two were 4.4mIU/L and 1.4ng/dL, respectively. Two of the patients had serum TSH concentration >25mIU/L that was considered as permanent primary hypothyroidism. Among nine hypothyroxinemia cases, two had elevated TSH levels (10.8±0.4mIU/L at the end of 8 weeks) and normal FT4 concentration, and were considered transient hypothyroidism. Seven cases had normal TSH levels (1.6±1.0mIU/L at 2 weeks, 3.5±2.8mIU/L at 8 weeks) and low FT4 concentrations.

Conclusions: Combined venous TSH and FT4 concentration at the end of the first postnatal month can be an efficient approach for detecting neonatal hypothyroidism.

Objetivo:: Avaliar a função da tireoide em recém-nascidos muito prematuros ou de muito baixo peso por meio dos níveis de combinação de TSH e T4 livre (FT4).

Métodos:: Os critérios de inclusão foram: todos os recém-nascidos muito prematuros (idade gestacional <32 semanas) ou de muito baixo peso (peso ao nascer ≤500g) com teste de função tireoidiana inicial e que foram admitidos na Unidade de Terapia Intensiva Neonatal do Hospital de Taleghani, Tabriz, Irã, de março de 2015 a março de 2016. Os critérios de exclusão foram: ausência de TFT inicial com qualquer anomalia congênita importante.

Resultados:: 95 neonatos com idade gestacional média de 29.5 semanas foram incluídos, e os níveis médios de tireotropina e FT4 na 2ª semana pós-natal foram 4.4mIU/L e 1.4ng/dL, respectivamente. Dois dos pacientes apresentavam concentração sérica de TSH >25mIU/L, considerada hipotireoidismo primário permanente. Entre nove casos de hipotiroxinemia, dois tinham níveis elevados de TSH (10.8±0.4mIU/L ao final de 8 semanas) e concentração normal de FT4 e foram considerados hipotireoidismo transitório. Sete casos tinham níveis normais de TSH (1,6±1,0mIU/L em 2 semanas, 3,5±2,8mIU/L em 8 semanas) e baixas concentrações de FT4.

Conclusões:: A concentração combinada de TSH e FT4 venoso no final do primeiro mês pós-natal pode ser uma abordagem eficiente para detectar hipotireoidismo neonatal.

PubMed Disclaimer

Conflict of interest statement

Conflict of interests

The authors declare there is no conflict of interests.

Figures

Figure 1.
Figure 1.. Study flowchart.
Figure 2.
Figure 2.. Follow-up flowchart.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Carrascosa A, Ruiz-Cuevas P, Clemente M, Salcedo S, Almar J. Thyroid function in 76 sick the very preterm neonates 30-36 weeks: results from a longitudinal study. J Pediatr Endocrinol Metab. 2008;21:237–44. doi: 10.1515/jpem.2008.21.3.237. - DOI - PubMed
    1. van Wassenaer AG, Kok JH. Hypothyroxinaemia and thyroid function after the very preterm birth. Semin Neonatol. 2004;9:3–11. doi: 10.1016/S1084-2756(03)00114-3. - DOI - PubMed
    1. Zoeller RT. Editorial: local control of the timing of thyroid hormone action in the developing human brain. J Clin Endocrinol Metab. 2004;89:3114–6. doi: 10.1210/jc.2004-0950. - DOI - PubMed
    1. Radetti G, Zavallone A, Gentili L, Beck-Peccoz P, Bona G. Foetal and neonatal thyroid disorders. Minerva Pediatr. 2002;54:383–400. - PubMed
    1. Waller DK, Anderson JL, Lorey F, Cunningham GC. Risk factors for congenital hypothyroidism: an investigation of neonate’s birth weight, ethnicity, and gender in California, 1990–1998. Teratology. 2000;62:36–41. doi: 10.1002/1096-9926(200007)62:1<36::aid-tera8>3.0.co;2-w. - DOI - PubMed