妊娠晚期碘营养状况及其新生儿生长指标的调查与分析

Maternal iodine nutrition during late pregnancy and neonatal physical development

目的通过对妊娠晚期正常孕妇尿碘浓度测定及膳食调查,评价此类人群碘营养状况,并分析其碘营养状况与胎儿生长发育之间的关系。方法通过队列研究方法,选取2014年12月至2015年8月产科门诊产前检查的妊娠晚期孕妇(孕28~34周)为研究对象。于入组及入院待产时进行两次膳食调查(包括碘相关食物频度法和24 h饮食日记),使用膳食营养软件计算膳食碘摄入量。每隔两周门诊产检时完成1次随机尿样本留取(3次/人),检测尿碘浓度。期间记录产检资料完成分组,并于入院分娩后记录其新生儿体格发育指标及促甲状腺激素结果。结果研究共纳入符合研究标准并完成研究方案的研究对象151例。尿碘中位数为100.0μg/L。研究对象碘缺乏、碘充足和碘超足量的比例分别为76.8%(n=116)、19.2%(n=29)和4.0%(n=6)。比较碘缺乏组(n=116)与非碘缺乏组(n=35)的新生儿出生体重[(3295±370)g比(3395±450)g,P=0.183]、身长[50.0(48.0,50.0)cm比50.0(49.0,51.0)cm,P=0.171]、头围[34.5(34.0,35.0)cm比34.5(34.0,35.0)cm,P=0.691]和促甲状腺激素值[(4.0±1.9)mIU/L比(4.2±2.5)mIU/L,P=0.438],两组间各指标差异均无统计学意义。结论根据世界卫生组织标准,碘营养缺乏在妊娠晚期孕妇人群中发生的比率高达76.8%。但研究对象中,不同碘营养状况孕妇其新生儿体格发育及相关指标比较未见明显差异。

Objective To monitor iodine nutrition of women during late pregnancy and examine the correlation between maternal urine iodine concentration and newborn physical development.Methods Prospective cohort study was conducted in 151 pregnant women at 28-34 weeks' gestation who accepted nutrition follow-up between December 2014 and August 2015. Participants were surveyed twice at enrollment and hospitalization for delivery respectively by iodine related food frequency method and 24 h diet diary and dietary nutrition software was used to calculate diet iodine consumption amount. Spot urine samples were taken three times totally every two weeks and data of antenatal care was recorded and the participants were divided into groups during this period. The physical development indexes and neonatal thyroid stimulating hormone (TSH) levels were obtained.Results Maternal median urinary iodine concentration was 100.0 μg/L. Using urinary iodine levels 150 μg/L and 249 μg/L as cut-off points, participants were divided into three subgroups as iodine-insufficient, iodine-adequate and iodine-over, with incidences of 76.8% (n=116), 19.2% (n=29), and 4.0% (n=6), respectively. Subgroup analysis showed no significant differences between the iodine-insufficient group (n=116) and the iodine-sufficient group (n=35) in neonatal weight [(3 295±370) vs (3 395±450)g, P=0.183], neonatal length [50.0(48.0, 50.0) vs 50.0(49.0, 51.0)cm, P=0.171], neonatal head circumference [34.5 (34.0, 35.0) vs 34.5(34.0, 35.0)cm, P=0.691], or neonatal thyroid stimulating hormone levels [(4.0±1.9) vs (4.2±2.5)mIU/L, P=0.438].Conclusions According to World Health Organization criteria, iodine deficiency rate in women during late pregnancy reaches 76.8%. In this study there is no significant difference in newborn physical development indexes among various pregnancy iodine nutrition statuses.