高水碘地区甲状腺抗体阴性妊娠期妇女甲状腺功能分析

Analysis on maternal thyroid function of pregnant women with negative thyroid antibody in high water iodine area

目的探讨高水碘地区甲状腺抗体阴性妇女妊娠各期甲状腺功能的变化特征。方法在高水碘地区选天津市静海县妇幼保健院（饮水水碘〉200μg／L）和在适碘地区选天津市和平区妇幼保健院（饮水水碘〈10μg／L，碘盐普及率〉90％，居民尿碘中位数〉100μg／L）作为调查地点。在妇幼保健院门诊，选取妊娠资料完整的妊娠早、中、晚期孕妇各50名，采集血样，用化学发光法检测甲状腺功能。同时收集日间随意一次尿样、家中饮用水样和食用盐样，尿碘测定采用砷铈催化分光光度法，水碘测定采用快速定量检测试剂盒，盐碘测定采用硫代硫酸钠滴定法。结果①甲状腺抗体阴性孕妇中，高水碘地区孕早期妇女血清TT4、TT3、FT4明显低于适碘地区（111．97nmol／Lvs140．46nmol／L，Z=3．56，P〈0．01；1．86nmol／Lvs52．26nmol／L，Z=2．35，P〈0．65；14．13pmol／Lvs16．32pmol／L，Z=5．14，P〈0．01）；孕中期妇女血清FT4、FT3明显低于适碘地区（11．98pmol／Lvs14．30pmol／L，Z=5．75，P〈0．01；4．04pmol／Lvs54．32pmol／L，Z=2．76，P〈0．01）；孕晚期妇女血清，TT3、TSH明显高于适碘地区（2188nmol／Lvs2．70nmol／L，Z=-2．27，P〈0．05；2．37mU／Lvs1．75mU／L。Z=-2．70，P〈0．01）。②高水碘地区孕妇家中饮水碘和孕妇尿碘明显高于适碘地区（205．57μg／Lvs8．22μg／L，Z=-14．71，P〈0．01；305．91μg／Lvs191．86μg／L，Z=-4．01，P〈0．01），家中盐碘明显低于适碘地区（26．5mg／kgvs31．7mg／kg，Z=5．68，P〈0．01）。③健康且没有甲状腺病史的被调查孕妇中，妊娠各期甲状腺抗体阳性率在高水碘和适碘地区之间比较差异无统计学意义（孕早期：10．20％vs10，64％；孕中期：14．00％vs9．52％：孕晚期：4．00％vs57．69％，P均〉0．05）。结论高水碘地区甲状腺抗体阴性孕妇妊娠各期甲状腺功能不同于适碘地区，对高水碘地区孕妇应加强孕期（特别是孕早、中期）甲状腺功能监测。

Objective To investigate the characteristics of maternal thyroid function of pregnant women with negative thyroid antibody in high water iodine area. Methods The investigation sites were selected, which were the Hospital for Women and Children of Jinghai county in the high water iodine area（drinking iodine 〉 200 μg/L） and the Hospital for Women and Children of Heping district in Tianjin in the adaptive iodine area （drinking iodine 〈 10 μg/L, popularization rate of iodized salt 〉 90%, residents urinary iodine 〉 200 μg/L）. In the maternal and child hospitals, 50 pregnant women of each stage from obstetric clinics in first, second, third term of pregnancy were selected, the blood samples were collected and the thyroid function were measured with chemiluminescence. Water, salt and diurnal optional urine samples were measured for iodine concentration. Iodine levels of urine, water, salt were determined respectively by As-Ce catalysis spectrophotometry method, quantitative determining kit which use time-recorded determination by catalytic effect on the As-Ce reaction and sodium hyposulfite titration method. Results （1）In pregnant women with negative thyroid antibody, serum TT4,TT3,FT4 in first term of pregnancy and TF4,TF3 in second term of pregnancy were significantly lower in high water iodine area than low water iodine area（111.97 nmol/L vs 140.46 mnol/L, Z =3.56, P 〈 0.01 ; 1.86 nmol/L vs 2.26 nmol/L, Z = 2.35,P 〈 0.05; 14.13 pmol/L vs 16.32 pmol/L, Z = 5.14, P 〈 0.01, and 11.98 pmol/L vs 14.30 pmol/L, Z = 5.75, P 〈 0.01 ; 4.04 pmol/L vs 4.32 pmol/L, Z = 2.76, P 〈 0.01 ）, while TT3 and TSH in third term of pregnancy were significantly higher（2.88 nmol/L vs 2.70 nmol/L, Z = - 2.27, P 〈 0.05 ; 2.37 mU/L vs 1.75 mU/L, Z = - 2.70, P 〈 0.01 ）. （2）Concentration of water iodine and urine iodine were higher（205.57 μg/L vs 8.26 μg/L, Z = - 14.71, P 〈 0.01 ; 305.91 g/L vs 191.86 g/L, Z = - 5.30, P 〈 0.01）, while salt iodine was lower（26.5 mg/kg vs 31.7 mg/kg, Z = - 5.86, P 〈 0.01） in high water iodine area. （3）Among 290 selected healthy pregnant women without medical history of thyroid diseases, there was no significant difference in positive rate of thyroid antibody in each term of pregnancy between high water iodine area and low water iodine area（ 10.20% vs 10.64% ; 14% vs 9.52% ; 4% vs 7.69% ; all P 〉 0.05）. Conclusions The thyroid function of pregnant women with negative thyroid antibody in high water iodine area is different from pregnant women in low water iodine area with universal salt iodization. Enhanced monitoring on thyroid function of pregnant women in high water iodine area should be performed, especially in first and second trimester.