孕期及脐血血清锌水平与新生儿出生体重关联的队列研究

The relationship of maternal and umbilical cord blood zinc level associated with newborn birth weight： a birth cohort study

目的探讨孕期和脐带血的血清锌水平和新生儿出生体重之间的关联。方法选取2013年5月至2014年9月在马鞍山市妇幼保健院进行产前检查的孕妇，于孕早、中和晚期进行随访，收集孕早期、孕中期及脐血样本，检测血清锌水平。最终3 239对母婴纳入分析。按照血清锌水平分为血清锌低（〈P25）、中（P25-P75）、高（〉P75）水平组，采用非条件多项式logistic回归模型分析孕早、中期和脐血血清锌与小于胎龄儿（SGA）及大于胎龄儿（LGA）之间的关联。结果孕早、中期和脐血血清锌浓度P50（P25-P75）分别为1 016.18（907.09-1 145.60）、813.36（732.47-897.89）和903.44（808.71-1 015.64）μg/L；血清锌缺乏检出率分别为1.5%（44/2 957）、15.9%（492/3 087）和6.5%（176/2 707）。SGA总检出率为9.7%（313/3 239），LGA总检出率为16.5%（536/3 239）。与血清锌高水平组相比，孕早期血清锌低水平组发生SGA的OR（95%CI）值为1.51（1.05-2.19）。孕中期和脐血的血清锌水平与SGA、LGA的关联均无统计学意义（P〉0.05）。结论马鞍山市孕妇锌营养状况处于较好水平，孕早期血清锌低水平会增加SGA的发生风险。

ObjectiveTo study serum zinc level in pregnancy and umbilical cord blood and their association with newborn birth weight.MethodsPregnant women accepting obstetric examination in Ma＇anshan Maternal and Child Care Center were recruited from May 2013 to September 2014. The follow up was conducted during their first, second and third trimesters of pregnancy and the self-designed questionnaire was used to collect information of social and demographic characteristics. Blood samples in the first, second pregnancy period and umbilical cord blood samples were collected and serum concentrations of zinc were assayed. 3 239 mother-infant entered the final analysis. We divided serum zinc level into low （〈P25）, medium （P25-P75） and high （〉P75） groups according to their exposure concentrations at each trimesters. Non-conditional multivariate logistic regression model was conducted to evaluate the association between serum zinc level in first, second trimesters of pregnancy and umbilical cord blood with small for gestational age （SGA） and large for gestational age （LGA）.ResultsSerum zinc level in P50 （P25-P75） during the first, second trimesters and cord blood were 1 016.18 （907.09-1 145.60）, 813.36 （732.47-897.89） and 903.44 （808.71-1 015.64） μg/L, respectively. The prevalence of zinc deficiency during the first, second trimesters and cord blood were 1.5% （44/2 957）, 15.9% （492/3 087） and 6.5% （176/2 707）, respectively. The prevalence of total SGA and LGA were 9.7% （313/3 239） and 16.5% （536/3 239）, respectively. Compared to high-level serum zinc group, the risk of SGA （OR （95%CI） in low-level serum zinc group during first trimesters was 1.51 （1.05-2.19））. Serum zinc level among second pregnancy period and umbilical cord blood had no statistically significant effect on SGA and LGA （both P values 〉0.05）.ConclusionZinc nutritional status of pregnant women in Ma＇anshan city was at a good level. The low serum zinc level in first trimester increased the risk of SGA.