Zhao Shu-Hua, Wang Lin-Lin, Xu Wen-Jie, Jin Lei, Zhang Le, Liu Jian-Meng
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2012 Jul;33(7):654-7.
To study the plasma folate concentrations in the third trimester of pregnant women and newborn babies so as to assess the association between them.
Pregnant women in Yuanshi and Laoting counties in Hebei province from May to June in 2009 were recruited with related information collected at enrollment. Those pregnant women being enrolled were followed up until delivery. Maternal blood was collected before delivery, and cord blood was collected after the expulsion of the placenta. Data from 437 pairs of women and newborns were analyzed. Plasma folate concentration was measured by Microbiological assay, with maternal plasma folate concentration < 6.8 nmol/L defined as folate deficiency. Neonatal plasma folate concentration below 10% was defined as relative deficiency. Student t-test and ANOVA were used to compare the plasma folate concentrations between the groups and χ(2) test was used to compare the situation of folate deficiency. In order to assess the association between maternal and newborn folate levels, logistic regression analysis was used to estimate the odds ratio of the neonatal plasma folate relative deficiency between the maternal folate deficient and normal groups after adjusting factors as age, BMI, region, career and education. Linear regression was used to test the trend by quintiles of maternal plasma folate concentration. Pearson's test was used to test the relationship between the ratio of neonatal and maternal plasma folate level and the level of maternal plasma folate.
The geometric mean of maternal plasma folate concentration was 8.0 (95%CI: 7.6 - 8.5) nmol/L and the deficiency was 29.3%, but in newborn babies, they were 24.0 (95%CI: 23.1 - 25.0) nmol/L and 0.9% respectively. The plasma folate level in newborn babies was 3.0 times as high as in maternal (t = 32.519, P < 0.01) but the neonatal plasma folate deficiency status was higher than in maternal (χ(2) = 137.2, P < 0.01). When compared with the normal plasma folate level group, the risk on neonatal plasma folate relative deficiency in the maternal folate deficiency group was significantly higher after adjusted for confounders (OR = 1.96, 95%CI: 1.02 - 3.80). The neonatal plasma folate level significantly increased along with the maternal plasma folate level (P(trend) < 0.05). The ratio of neonatal and maternal plasma folate level was significantly inversely correlated with the maternal folate level (r = -0.810, P < 0.001).
Folate status in newborns was much better than in their mothers', in the northern rural areas of China. The maternal folate status was positively correlated with their offspring's. Active placental transport for folate was significantly increasing when the maternal plasma folate level decreased.
研究孕妇孕晚期及新生儿血浆叶酸浓度，以评估两者之间的关联。
选取2009年5月至6月河北省元氏县和乐亭县的孕妇，登记时收集相关信息。对入选的孕妇进行随访直至分娩。分娩前采集母血，胎盘娩出后采集脐血。分析437对母婴的数据。采用微生物法测定血浆叶酸浓度，母血血浆叶酸浓度<6.8 nmol/L定义为叶酸缺乏。新生儿血浆叶酸浓度低于10%定义为相对缺乏。采用Student t检验和方差分析比较各组血浆叶酸浓度，采用χ²检验比较叶酸缺乏情况。为评估母婴叶酸水平之间的关联，采用logistic回归分析估计调整年龄、BMI、地区、职业和教育等因素后，母血叶酸缺乏组和正常组新生儿血浆叶酸相对缺乏的比值比。采用线性回归按母血血浆叶酸浓度五分位数检验趋势。采用Pearson检验检验新生儿与母血血浆叶酸水平比值与母血血浆叶酸水平之间的关系。
母血血浆叶酸浓度几何均数为8.0（95%CI：7.6 - 8.5）nmol/L，缺乏率为29.3%，而新生儿分别为24.0（95%CI：23.1 - 25.0）nmol/L和0.9%。新生儿血浆叶酸水平是母血的3.0倍（t = 32.519，P < 0.01），但新生儿血浆叶酸缺乏状况高于母血（χ² = 137.2，P < 0.01）。与血浆叶酸正常水平组相比，调整混杂因素后，母血叶酸缺乏组新生儿血浆叶酸相对缺乏风险显著更高（OR = 1.96，95%CI：1.02 - 3.80）。新生儿血浆叶酸水平随母血血浆叶酸水平显著升高（P趋势<0.05）。新生儿与母血血浆叶酸水平比值与母血叶酸水平显著负相关（r = -0.810，P < 0.001）。
在中国北方农村地区，新生儿叶酸状况优于其母亲。母血叶酸状况与其后代叶酸状况呈正相关。当母血血浆叶酸水平降低时，胎盘对叶酸的主动转运显著增加。
