Lumley Judith, Watson Lyndsey, Watson Max, Bower Carol
Mother and Child Health Research, La Trobe University, 324-328 Little Lonsdale Street, Melbourne, Victoria, Australia, 3000.
Cochrane Database Syst Rev. 2011 Apr 13;2011(4):CD001056. doi: 10.1002/14651858.CD001056.pub2.
Neural tube defects arise during the development of the brain and spinal cord.
The objective of this review was to assess the effects of increased consumption of folate or multivitamins on the prevalence of neural tube defects periconceptionally (that is before pregnancy and in the first two months of pregnancy).
We searched the Cochrane Pregnancy and Childbirth Group trials register. Date of last search: April 2001.
Randomised and quasi-randomised trials comparing periconceptional supplementation by multivitamins with placebo, folate with placebo, or multivitamins with folate; different dosages of multivitamins or folate; prepregnancy dietary advice and counselling in primary care settings to increase the consumption of folate-rich foods, or folate-fortified foods, with standard care; increased intensity of information provision with standard public health dissemination.
Two reviewers assessed trial quality and extracted data.
Four trials of supplementation involving 6425 women were included. The trials all addressed the question of supplementation and they were of variable quality. Periconceptional folate supplementation reduced the incidence of neural tube defects (relative risk 0.28, 95% confidence interval 0.13 to 0.58). Folate supplementation did not significantly increase miscarriage, ectopic pregnancy or stillbirth, although there was a possible increase in multiple gestation. Multivitamins alone were not associated with prevention of neural tube defects and did not produce additional preventive effects when given with folate.One dissemination trial, a community randomised trial, was identified involving six communities, matched in pairs, and where 1206 women of child-bearing age were interviewed following the dissemination intervention. This showed that the provision of printed material increased the awareness of the folate/neural tube defects association by 4%, (odds ratio 1.37, 95% confidence interval 1.33 to 1.42).
AUTHORS' CONCLUSIONS: Periconceptional folate supplementation has a strong protective effect against neural tube defects. Information about folate should be made more widely available throughout the health and education systems. Women whose fetuses or babies have neural tube defects should be advised of the risk of recurrence in a subsequent pregnancy and offered continuing folate supplementation. The benefits and risks of fortifying basic food stuffs, such as flour, with added folate remain unresolved.
神经管缺陷发生于脑和脊髓发育期间。
本综述的目的是评估孕期前（即怀孕前及怀孕后的头两个月）增加叶酸或多种维生素的摄入量对神经管缺陷患病率的影响。
我们检索了Cochrane妊娠与分娩组试验注册库。最后检索日期：2001年4月。
比较孕期前补充多种维生素与安慰剂、叶酸与安慰剂、或多种维生素与叶酸的随机和半随机试验；不同剂量的多种维生素或叶酸；在初级保健机构中提供孕前饮食建议和咨询以增加富含叶酸食物或叶酸强化食物的摄入量，并与标准护理进行比较；与标准公共卫生宣传相比，增加信息提供强度。
两名评价员评估试验质量并提取数据。
纳入了4项涉及6425名妇女的补充剂试验。这些试验均涉及补充剂问题，质量参差不齐。孕期前补充叶酸可降低神经管缺陷的发生率（相对危险度0.28，95%可信区间0.13至0.58）。补充叶酸虽可能增加多胎妊娠的几率，但并未显著增加流产、宫外孕或死产的发生率。单独补充多种维生素与预防神经管缺陷无关，与叶酸一起服用时也未产生额外的预防效果。一项传播试验，即社区随机试验，涉及6个配对的社区，在传播干预后对1206名育龄妇女进行了访谈。结果显示，提供印刷材料使叶酸/神经管缺陷关联的知晓率提高了4%（优势比1.37，95%可信区间1.33至1.42）。
孕期前补充叶酸对神经管缺陷有很强的保护作用。应在整个卫生和教育系统中更广泛地提供有关叶酸的信息。对于胎儿或婴儿患有神经管缺陷的妇女，应告知其后续妊娠复发的风险，并建议继续补充叶酸。在基础食品（如面粉）中添加叶酸强化的益处和风险仍未解决。
