Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
Epidemiology. 2010 Jan;21(1):62-9. doi: 10.1097/EDE.0b013e3181c1592b.
An adequate iodine intake during pregnancy is essential for the synthesis of maternal thyroid hormones and normal brain development in the fetus. Scant evidence is available on the effects and safety of iodine supplementation during pregnancy in areas with adequate or mildly deficient iodine intake. We examined the association of maternal iodine intake and supplementation with thyroid function before 24 weeks of gestation in population-based samples from 3 different areas in Spain.
A cross-sectional study of 1844 pregnant women (gestational age range 8-23 weeks) was carried out in 3 areas in Spain (Guipúzcoa, Sabadell, Valencia), during the period 2004-2008. We measured levels of free thyroxine and thyroid-stimulating hormone (TSH) in serum, iodine in a spot urine sample, and questionnaire estimates of iodine intake from diet, iodized salt and supplements. Adjusted associations were assessed by multiple linear regression and logistic regression analyses.
There was an increased risk of TSH above 3 muU/mL in women who consumed 200 microg or more of iodine supplements daily compared with those who consumed less than 100 microg/day (adjusted odds ratio = 2.5 [95% confidence interval = 1.2 to 5.4]). We observed no association between urinary iodine and TSH levels. Pregnant women from the area with the highest median urinary iodine (168 microg/L) and highest supplement coverage (93%) showed the lowest values of serum free thyroxine. (geometric mean = 10.09 pmol/L [9.98 to 10.19]).
Iodine supplement intake in the first half of pregnancy may lead to maternal thyroid dysfunction in iodine-sufficient or mildly iodine-deficient populations.
妊娠期间摄入足够的碘对于合成母体甲状腺激素和胎儿正常大脑发育至关重要。在碘摄入充足或轻度不足的地区，关于妊娠期间补充碘的效果和安全性的证据很少。我们在西班牙三个不同地区的基于人群的样本中，研究了妊娠前 24 周内母体碘摄入量和补充与甲状腺功能之间的关系。
这是一项在西班牙三个地区（吉普斯夸、萨瓦德尔、巴伦西亚）进行的横断面研究，纳入了 1844 名妊娠妇女（妊娠年龄 8-23 周），研究时间为 2004-2008 年。我们测量了血清中的游离甲状腺素和促甲状腺激素（TSH）水平、尿液样本中的碘含量，以及问卷中饮食、碘盐和补充剂的碘摄入量估计值。采用多元线性回归和 logistic 回归分析评估调整后的关联。
与每天摄入碘补充剂少于 100μg 的妇女相比，每天摄入 200μg 或更多碘补充剂的妇女 TSH 超过 3muU/mL 的风险增加（调整后的比值比=2.5[95%置信区间=1.2 至 5.4]）。我们没有观察到尿碘与 TSH 水平之间的关联。尿碘中位数最高（168μg/L）、补充剂覆盖率最高（93%）的地区的孕妇，血清游离甲状腺素值最低（几何均数=10.09pmol/L[9.98 至 10.19]）。
在碘充足或轻度碘不足的人群中，妊娠前半期补充碘可能导致母体甲状腺功能障碍。
