孕期碘营养状况对新生儿足跟血促甲状腺激素水平影响的横断面研究

Objective Congenital hypothyroidism(CH) is one of the causes of intellectual disability in children. Neonatal heel blood thyroid stimulating hormone(TSH) screening is a means to identify this disease. The iodine nutritional status during pregnancy is an important factor affecting fetal thyroid development, but the specific quantitative relationship between the two has not been fully clarified. Therefore, this study aims to systematically evaluate the correlation between the two. Methods A cross-sectional study was conducted, involving 211 pregnant women and their newborns, we collected maternal urinary iodine concentration(UIC), urinary creatinine(CR), urinary iodine-to-creatinine ratio(UICR), maternal thyroid function indices, iodine-salt use, and neonatal heel-blood TSH. Analyses included descriptive stats, Fisher's exact test, scatterplots with locally estimated scatterplot smoothing(LOESS), and bayesian regression. Results Median maternal UIC was 77.05 μg/L, indicating iodine insufficiency. The prevalence of elevated neonatal TSH(≥5 μIU/mL) was 18.48%, with no difference among pregnancy periods. Scatterplots and LOESS curves suggested an inverse UIC-TSH relationship. Bayesian regression confirmed a negative UIC effect on TSH(posterior mean=-0.0117). CR had a weak positive link with TSH. Maternal age, UICR, thyroid indices, iodine-salt use, and gestational week had no significant TSH association. Conclusion In this cohort, maternal UIC was an independent neonatal TSH correlate, with higher UIC associated with lower TSH. These findings highlight the need for better pregnancy iodine monitoring. Larger prospective studies are needed to define optimal maternal iodine status for CH prevention.