Iodine and Reproduction

先兆子痫是一种包括高血压和蛋白尿的妊娠疾病，是孕产妇和胎儿发病和死亡的主要原因。一些研究（但不是全部）发现，患有先兆子痫的女性体内的碘含量明显低于健康孕妇。解决这个问题很重要，因为孕期缺碘在美国和包括芬兰在内的欧洲部分地区很常见。我们进行了一项巢式病例对照研究，以确定子痫前期的风险是否与碘状态有关。我们从芬兰的所有新生儿中选择204名先兆子痫妇女和246名未受影响的对照组，测量了10-14孕周时的血清碘、甲状腺球蛋白（Tg）和促甲状腺激素（TSH）。碘（病例平均值= 26.04 ng/mL，对照组平均值= 27.88 ng/mL, p = 0.995）、Tg（病例平均值= 31.11 ng/mL，对照组平均值= 29.61 ng/mL, p = 0.996）、TSH（病例平均值= 1.30 mIU/L，对照组平均值= 1.24 mIU/L, p = 0.896）水平在两组间无显著差异。在调整已知危险因素后，子痫前期风险与碘、Tg或TSH之间没有显著关系。考虑到孕期碘缺乏症的高发率，这些结果令人放心。

Preeclampsia, a pregnancy disorder that includes hypertension and proteinuria, is a major cause of maternal and fetal morbidity and mortality. Some studies, but not all, have found that women with preeclampsia have significantly lower iodine levels than healthy pregnant women. Resolving this issue is important because iodine deficiency in pregnancy is common in the USA and parts of Europe including Finland. We conducted a nested case-control study to determine whether the risk for preeclampsia is associated with iodine status. We measured serum iodine, thyroglobulin (Tg), and thyroid stimulating hormone (TSH) at 10-14 weeks gestational age in 204 women with preeclampsia and 246 unaffected controls selected from all births in Finland. We found no significant difference in iodine (case mean = 26.04 ng/mL, control mean = 27.88 ng/mL, p = 0.995), Tg (case mean = 31.11 ng/mL, control mean = 29.61 ng/mL, p = 0.996), and TSH (case mean = 1.30 mIU/L, control mean = 1.24 mIU/L, p = 0.896) levels between cases and controls. There was no significant relationship between preeclampsia risk and iodine, Tg, or TSH after adjustment for known risk factors. These results are reassuring given the high prevalence of iodine deficiency in pregnancy. Severe iodine deficiency or excess during pregnancy can cause congenital hypothyroidism (CH). Iodine deficiency is common in pregnant women in the United States. We conducted a nested case-control study in a cohort of 2.5 million births in California to determine whether iodine status is related to CH in a US population. Dried blood spots from 907 newborns with CH identified by newborn screening and 909 unaffected controls matched by month of birth were obtained from the California Newborn Screening Program to measure whole-blood iodine concentration. Iodine status was compared between cases and controls, and logistic regression was used to assess the association between CH status and blood iodine concentrations. Iodine status was also compared between cases and controls among infants treated in a neonatal intensive care unit (NICU) because CH has been reported in infants exposed to high levels of iodine in the NICU. Blood iodine concentrations did not differ significantly between cases (median: 20.0 ng/mL; IQR: 12.1-29.8 ng/mL) and controls (median: 20.3 ng/mL; IQR: 12.5-30.9 ng/mL; P = 0.59). Neither extremely high nor extremely low blood iodine concentrations (1st, 5th, 95th, and 99th percentiles of the distribution) were more common in cases. Among infants treated in NICUs, however, cases had significantly (P = 0.01) higher iodine (median: 22.7 ng/mL; IQR: 16.4-32.1 ng/mL) compared with controls (median: 17.3 ng/mL; IQR: 8.3-26.6 ng/mL). CH cases did not have significantly higher or lower iodine in this population, which is reassuring given that maternal iodine deficiency is common in the United States. Among newborns in the NICU, CH cases had higher blood iodine concentrations compared with controls, suggesting that excess iodine exposure in the NICU could be causing CH. It may be beneficial to monitor iodine exposure from surgical procedures, imaging, and iodine-containing disinfectants and to consider non-iodine alternatives.