The Effects of Maternal Subclinical Hypothyroidism on Fetal Thymus Size: A Prospective Study

<b>Objective</b>: This study investigated the impact of maternal subclinical hypothyroidism on fetal thymus size and development and explored how inadequate thyroid hormone production in pregnant women affects the fetal thymus. <b>Methods</b>: Conducted at the Giresun Obstetr...

Full description

Saved in:
Bibliographic Details
Main Authors: Mehmet Albayrak, Bekir Yükcü
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Diagnostics
Subjects:
Online Access:https://www.mdpi.com/2075-4418/15/3/276
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850200239950004224
author Mehmet Albayrak
Bekir Yükcü
author_facet Mehmet Albayrak
Bekir Yükcü
author_sort Mehmet Albayrak
collection DOAJ
description <b>Objective</b>: This study investigated the impact of maternal subclinical hypothyroidism on fetal thymus size and development and explored how inadequate thyroid hormone production in pregnant women affects the fetal thymus. <b>Methods</b>: Conducted at the Giresun Obstetrics, Gynecology, and Pediatrics Training and Research Hospital, this case–control study involved 86 pregnant women, 43 with hypothyroidism and 43 without. Maternal thyroid function was assessed using TSH and free T4 levels, and fetal thymus size and thymus–thorax ratio were measured using ultrasound. Exclusion criteria were chronic hypertension, gestational hypertension or eclampsia, multiple pregnancies, infectious diseases, renovascular diseases, diagnosed with hypothyroidism prior to pregnancy and other endocrine disorders, fetal cardiac diseases, and morbid obesity. Data collected included maternal age, gestational week, number of pregnancies, parity, number of living children, thyroid-stimulating hormone (TSH) and Free thyroxine 4 (T4) levels, and fetal thymus measurements (transverse diameter and thymus/thorax ratio). Statistical analyses were performed using the Mann–Whitney U test and logistic regression analysis. The relationships between TSH, thymus diameters, thorax diameters, and the thymus–thorax ratio were evaluated using Spearman’s correlation coefficient. <b>Results</b>: The thymus–thorax ratio was significantly reduced in the hypothyroid group (<i>p</i> = 0.003). Logistic regression analysis identified TSH as an independent risk factor for a low thymus–thorax ratio, with each unit increase in TSH associated with a 1.345-fold higher likelihood of having a low thymus–thorax ratio. A significant negative correlation was found between TSH levels and the TTR ratio (Spearman’s correlation coefficient r = −0.338, <i>p</i> = 0.001). <b>Conclusions</b>: An association was identified between maternal TSH levels and the thymus–thorax ratio, with increasing TSH levels correlating with a decrease in the thymus–thorax ratio. Regular monitoring of thyroid hormone levels during pregnancy and appropriate replacement treatment in cases of deficiency are crucial for optimal fetal thymus development. Further multicenter studies are needed to confirm these findings and investigate the long-term implications of altered fetal thymus development.
format Article
id doaj-art-914352617bef44b8a57b5dfa010c76a0
institution OA Journals
issn 2075-4418
language English
publishDate 2025-01-01
publisher MDPI AG
record_format Article
series Diagnostics
spelling doaj-art-914352617bef44b8a57b5dfa010c76a02025-08-20T02:12:24ZengMDPI AGDiagnostics2075-44182025-01-0115327610.3390/diagnostics15030276The Effects of Maternal Subclinical Hypothyroidism on Fetal Thymus Size: A Prospective StudyMehmet Albayrak0Bekir Yükcü1Perinatology Department, Giresun Obstetric and Pediatric Disease Education and Research Hospital, 28200 Giresun, TürkiyePediatric Cardiology Department, Giresun Obstetric and Pediatric Disease Education and Research Hospital, 28200 Giresun, Türkiye<b>Objective</b>: This study investigated the impact of maternal subclinical hypothyroidism on fetal thymus size and development and explored how inadequate thyroid hormone production in pregnant women affects the fetal thymus. <b>Methods</b>: Conducted at the Giresun Obstetrics, Gynecology, and Pediatrics Training and Research Hospital, this case–control study involved 86 pregnant women, 43 with hypothyroidism and 43 without. Maternal thyroid function was assessed using TSH and free T4 levels, and fetal thymus size and thymus–thorax ratio were measured using ultrasound. Exclusion criteria were chronic hypertension, gestational hypertension or eclampsia, multiple pregnancies, infectious diseases, renovascular diseases, diagnosed with hypothyroidism prior to pregnancy and other endocrine disorders, fetal cardiac diseases, and morbid obesity. Data collected included maternal age, gestational week, number of pregnancies, parity, number of living children, thyroid-stimulating hormone (TSH) and Free thyroxine 4 (T4) levels, and fetal thymus measurements (transverse diameter and thymus/thorax ratio). Statistical analyses were performed using the Mann–Whitney U test and logistic regression analysis. The relationships between TSH, thymus diameters, thorax diameters, and the thymus–thorax ratio were evaluated using Spearman’s correlation coefficient. <b>Results</b>: The thymus–thorax ratio was significantly reduced in the hypothyroid group (<i>p</i> = 0.003). Logistic regression analysis identified TSH as an independent risk factor for a low thymus–thorax ratio, with each unit increase in TSH associated with a 1.345-fold higher likelihood of having a low thymus–thorax ratio. A significant negative correlation was found between TSH levels and the TTR ratio (Spearman’s correlation coefficient r = −0.338, <i>p</i> = 0.001). <b>Conclusions</b>: An association was identified between maternal TSH levels and the thymus–thorax ratio, with increasing TSH levels correlating with a decrease in the thymus–thorax ratio. Regular monitoring of thyroid hormone levels during pregnancy and appropriate replacement treatment in cases of deficiency are crucial for optimal fetal thymus development. Further multicenter studies are needed to confirm these findings and investigate the long-term implications of altered fetal thymus development.https://www.mdpi.com/2075-4418/15/3/276maternal subclinical hypothyroidismfetal thymusthyroid hormonespregnancyfetal developmentthymus–thorax ratio
spellingShingle Mehmet Albayrak
Bekir Yükcü
The Effects of Maternal Subclinical Hypothyroidism on Fetal Thymus Size: A Prospective Study
Diagnostics
maternal subclinical hypothyroidism
fetal thymus
thyroid hormones
pregnancy
fetal development
thymus–thorax ratio
title The Effects of Maternal Subclinical Hypothyroidism on Fetal Thymus Size: A Prospective Study
title_full The Effects of Maternal Subclinical Hypothyroidism on Fetal Thymus Size: A Prospective Study
title_fullStr The Effects of Maternal Subclinical Hypothyroidism on Fetal Thymus Size: A Prospective Study
title_full_unstemmed The Effects of Maternal Subclinical Hypothyroidism on Fetal Thymus Size: A Prospective Study
title_short The Effects of Maternal Subclinical Hypothyroidism on Fetal Thymus Size: A Prospective Study
title_sort effects of maternal subclinical hypothyroidism on fetal thymus size a prospective study
topic maternal subclinical hypothyroidism
fetal thymus
thyroid hormones
pregnancy
fetal development
thymus–thorax ratio
url https://www.mdpi.com/2075-4418/15/3/276
work_keys_str_mv AT mehmetalbayrak theeffectsofmaternalsubclinicalhypothyroidismonfetalthymussizeaprospectivestudy
AT bekiryukcu theeffectsofmaternalsubclinicalhypothyroidismonfetalthymussizeaprospectivestudy
AT mehmetalbayrak effectsofmaternalsubclinicalhypothyroidismonfetalthymussizeaprospectivestudy
AT bekiryukcu effectsofmaternalsubclinicalhypothyroidismonfetalthymussizeaprospectivestudy