[Thyroid function for Chinese pregnant women in 2010-2012]

Area of Science:

• Endocrinology
• Public Health
• Nutritional Science

Background:

• Thyroid function is crucial during pregnancy for both maternal and fetal health.
• Iodine deficiency can significantly impact thyroid hormone production and function.
• Regional variations in nutritional status may affect thyroid health in pregnant populations.

Purpose of the Study:

• To assess thyroid function and iodine nutritional status in pregnant women across China.
• To determine plasma levels of thyrotropin (TSH), free triiodothyronine (FT3), and free thyroxine (FT4).

Main Methods:

• Analysis of 877 plasma samples from pregnant women in the 2010-2012 China National Nutrition and Health Survey.
• Measurement of TSH, FT3, and FT4 using automated chemiluminescence immunoassay.
• Evaluation of thyroid function based on determined plasma hormone levels.

Main Results:

• A normal thyroid function rate of 78.1% was observed, lower in urban areas (71.2%).
• Subclinical hypothyroidism was the most prevalent dysfunction (10.5%), highest in rural poverty regions (14.5%).
• Thyroid function rates declined in later pregnancy trimesters compared to earlier ones.

Conclusions:

• Less than 80% of pregnant women in China exhibit normal thyroid function.
• Subclinical hypothyroidism is the primary thyroid dysfunction during pregnancy.
• The link between subclinical hypothyroidism and iodine intake, especially deficiency, requires continued attention.