Health Education Division, Shanxi Children's Hospital/Shanxi Maternal and Child Health Care Hospital, Taiyuan, P. R. China.
Institute of Reproductive and Child Health/National Health Commission Key Laboratory of Reproductive Health, Beijing, China.
Matern Child Nutr. 2019 Oct;15(4):e12828. doi: 10.1111/mcn.12828. Epub 2019 May 23.
Folate insufficiency during the periconceptional period increases the risk of neural tube defects (NTDs) in offspring, and folic acid supplementation substantially reduces the risk. Widespread large-scale folic acid supplementation (0.4-mg folic acid tablet) has been adopted as a main strategy to prevent NTDs in China since 2009. We examined folate concentrations in plasma and red blood cells (RBCs) of pregnant women and the factors associated with blood folate concentrations in a population with a high prevalence of NTDs in northern China. A cross-sectional survey was conducted in 2014, and 1,107 pregnant women were recruited from 11 county or city maternal and child health centres across Shanxi province. Microbiological assays were used to determine folate concentrations. Factors associated with blood folate insufficiency were identified. The median (25th and 75th percentiles) folate concentrations were 28.4 (17.6, 45.2) nmol L and 1,001.2 (658.7, 1,402.5) nmol L in plasma and RBCs, respectively. According to the proposed RBC (906 nmol L ) concentrations for optimal NTD prevention, 42.4% participants had RBC folate insufficiency. Rural women had a higher proportion of folate insufficiency than urban women. Folic acid supplementation was the only factor associated with RBC folate insufficiency. A large proportion of women had RBC folate concentrations that are not optimal for the prevention of NTDs despite free access to folic acid supplements. Actions that aim to improve folic acid supplementation compliance are needed to reach the full potential of the nationwide folic acid supplementation programme in terms of NTD prevention.
在围孕期叶酸不足会增加后代神经管缺陷（NTD）的风险，而叶酸补充剂可显著降低这种风险。自 2009 年以来，中国广泛采用了大规模叶酸补充（0.4 毫克叶酸片）作为预防 NTD 的主要策略。我们检测了高发 NTD 地区中国北方孕妇的血浆和红细胞（RBC）中叶酸浓度，以及与血叶酸浓度相关的因素。2014 年进行了一项横断面研究，在山西省 11 个县/市妇幼保健中心招募了 1107 名孕妇。采用微生物学检测法测定叶酸浓度。确定了与血叶酸不足相关的因素。血浆和 RBC 中叶酸中位数（25 分位和 75 分位）分别为 28.4（17.6，45.2）nmol/L 和 1001.2（658.7，1402.5）nmol/L。根据 RBC（906 nmol/L）浓度来预防 NTD 的最佳值，42.4%的参与者存在 RBC 叶酸不足。农村妇女叶酸不足的比例高于城市妇女。叶酸补充是唯一与 RBC 叶酸不足相关的因素。尽管免费提供叶酸补充剂，但仍有很大比例的妇女 RBC 叶酸浓度不能达到预防 NTD 的最佳水平。需要采取行动，提高叶酸补充剂的依从性，以充分发挥全国叶酸补充计划在预防 NTD 方面的潜力。
