Abstract
Objective
Thyroid hormones are crucial for fetal growth, especially the development of the central
nervous system. The impact of maternal obesity on neonatal thyroid-stimulating hormone
(TSH) levels, however, remains underexplored. This study aimed to evaluate the influence
of maternal body mass index (BMI) on neonatal TSH (nTSH) levels.
Study Design
A prospective observational study was conducted involving 934 newborns with a gestational
age greater than 35 weeks, born between July 2021 and January 2022. nTSH levels were
measured from capillary blood samples obtained during routine congenital hypothyroidism
screening. Maternal data, including age, pre-pregnancy BMI, weight gain during pregnancy,
and thyroid function, were collected.
Results
The mean maternal BMI was 24 ± 4 kg/m2, and the mean nTSH level was 2 ± 2.7 mIU/L. No significant difference in nTSH levels
was observed between infants of mothers with BMI ≥25 and BMI <25 (p = 0.069). When mothers were categorized into five BMI groups, the only significant
difference observed between the groups was in weight gain during pregnancy (p = 0.001). Additionally, a positive correlation between maternal BMI and neonatal
birth weight, height, and head circumference was observed. A weak positive correlation
between maternal weight gain and nTSH levels (r = 0.204, p = 0.001) was also noted.
Conclusion
Our study indicates a potential relationship between maternal obesity and nTSH levels,
suggesting that maternal BMI may influence neonatal thyroid function.
Key Points
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There is a potential relationship between maternal obesity and neonatal TSH levels.
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Maternal BMI and weight gain might influence neonatal thyroid function.
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The study emphasizes the need for close monitoring of pregnant women with obesity.
Keywords
maternal BMI - neonatal TSH - neonatal thyroid function - gestational weight gain
- pregnancy outcomes
