甘肃省碘适量地区农村孕妇碘营养及甲状腺功能变化研究

摘要

Objective To assess the iodine nutrition and thyroid function of pregnant women during different periods of pregnancy,to provide evidence for guiding iodine supplementation for them.Methods A cross-sectional survey was performed in 215 pregnant women in Yongjing couty from May to June 2013.Samples of blood and random urine were collected,and serum thyrotrophin (TSH),free triiodothyronine (FT3),free thyroxine (FT4),anti-thyroid peroxidase (anti-TPO),antithyroglobulin (anti-TG) and urinary iodine were measured.Results The medians of urinary iodine from the three groups of pregnant women (first,second and third trimester) were 189.8 μg/L,152.5 μg/L and 144.9 μg/L respectively.With the exception of pregnant women in the third trimester,the urinary iodine medians of pregnant women in the first and second trimesters were within the 150-249 μg/L range which was defined as optimal by WHO/UNICEF/ICCIDD.With the increase of gestational age,the level of FT3 decreased (P＜0.05),with the FT3 levels in the first trimester were higher than those in the second or third trimester (P＜0.05).The difference of TSH levels among the three groups of pregnant women was statistically significant (P＜0.01),with a U-shaped curve seen between the iodine TSH levels and the gestational age.The medians of anti-TG and anti-TPO appeared the lowest in the first trimester,and remained at a high level in women at second and third trimesters.Significant diffierence was seen in anti-TG,anti-TPO levels of the three groups of pregnant women (first,second and third trimester) (P＜0.01).The incidence of thyroidfunction disorder was 1.86％,including subclinical hypothyroidism accounted for 1.40％,and hypothyroidism accounted for 0.47％.The incidence of thyroidfunction disorder mainly appeared in the early pregnancy.Abnormal FT3,TSH,positive anti-TG and anti-TPO were mainly seen during early pregnancy.The changes of TSH,FT3,FT4,anti-TG and anti-TPO along with the changes of urine iodine levels were not obvious.Conclusion With the increase of gestational age,the incidence of iodine deficiency also increased among pregnant women.Abnormal thyroid hormones,TSH,positive anti-TG and anti-TPO were mainly existed in the early pregnancy.Programs as monitoring urinary iodine as well as thyroid function targeting all the pregnant women should be carried out.%目的 评价碘适量农村地区不同孕期孕妇碘营养和甲状腺功能状态及分析其变化规律,为孕妇科学补碘提供指导.方法 2013年5-6月在甘肃省永靖县采用横断面方法随机抽取215名农村常住健康孕妇,其中孕早期(0～13周)、孕中期(14 ～ 27周)、孕晚期(28～40周)分别为70、72和73名.采集孕妇一次性随机尿样10 ml测定尿碘,血样测定促甲状腺素(TSH)、血清游离甲状腺素(FT4)、游离三碘甲状腺原氨酸(FT3)、甲状腺球蛋白抗体(TGAb)、甲状腺过氧化物酶抗体(TPOAb),同时采集居民家中食盐、饮用水分别测定盐碘和水碘含量.结果 孕早、中、晚期妇女尿碘中位数分别为189.8、152.5和144.9 μg/L,除孕晚期妇女外其余两组妇女尿碘中位数均达到WHO推荐标准.随孕龄的增加FT3水平呈下降趋势(F=6.983,P=0.001),孕早期FT3水平高于孕中期和孕晚期(P＜0.05);各孕期FT4水平变化不大(P＞0.05);TSH水平随孕期增加,呈现“U”形曲线,不同孕期TSH水平差异有统计学意义(P＜0.01);孕早期TGAb、TPOAb中位数最低,孕中期和孕晚期保持较高水平,不同孕期抗体水平差异有统计学意义(P＜0.01).孕妇甲状腺功能紊乱发生率为1.86％,其中亚临床甲状腺功能减低占1.40％,甲状腺功能减低占0.47％,主要分布在孕早期.FT3、TSH水平异常者和TGAb、TPOAb阳性者均主要分布在孕早期.TSH、FT3、FT4、TGAb和TPOAb随尿碘水平变化不明显.结论 随孕龄增加孕妇碘营养不足亦增加,甲状腺激素、TSH及甲状腺抗体异常均主要分布在孕早期,建议孕妇全程开展甲状腺功能和尿碘检查.