Pena-Rosas J P, Viteri F E
U.S. Centers for Disease Control and Prevention (CDC), International Micronutrient Malnutrition Prevention and Control Program (IMMPaCt), 4770 Buford Highway MS K25, Atlanta, GA 30341, USA.
Cochrane Database Syst Rev. 2006 Jul 19(3):CD004736. doi: 10.1002/14651858.CD004736.pub2.
It has been suggested that routine intake of supplements containing iron or combination of iron and folic acid during pregnancy improves maternal health and pregnancy outcomes.
To assess the efficacy, effectiveness and safety of routine antenatal daily or intermittent iron supplementation with or without folic acid during pregnancy on the health of mothers and newborns.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2005). Additionally, we contacted relevant organizations for the identification of ongoing and unpublished studies.
All randomised or quasi-randomised trials evaluating the effect of routine supplementation with iron or combination of iron and folic acid during pregnancy.
We assessed trials for methodological quality using the standard Cochrane criteria. Two authors independently assessed the trials for inclusion and one author extracted data. We collected information on randomisation method, allocation concealment, blinding and loss to follow up. The primary outcomes included maternal and infant clinical and laboratory outcomes.
Forty trials, involving 12706 women, were included in the review. Overall, the results showed significant heterogeneity across most prespecified outcomes. Heterogeneity could not be explained by standard sensitivity analyses including quality assessment; therefore, all results were analysed assuming random-effects. Very limited information related to clinical maternal and infant outcomes was available in the included trials. The data suggest that daily antenatal iron supplementation increases haemoglobin levels in maternal blood both antenatally and postnatally. It is difficult to quantify this increase due to significant heterogeneity between the studies. Women who receive daily antenatal iron supplementation are less likely to have iron deficiency and iron-deficiency anaemia at term as defined by current cut-off values. Side-effects and haemoconcentration are more common in women who receive daily iron supplementation. No differences were evident between daily and weekly supplementation with regards to gestational anaemia; haemoconcentration during pregnancy appears less frequent with the weekly regimen. The clinical significance of hemoconcentration defined as haemoglobin greater than 130 g/L remains uncertain.
AUTHORS' CONCLUSIONS: Further studies are needed to assess the effects of routine antenatal supplementation with iron or a combination of iron and folic acid on clinically important maternal and infant outcomes.
有人提出孕期常规摄入含铁或铁与叶酸组合的补充剂可改善孕产妇健康及妊娠结局。
评估孕期每日或间歇补充铁剂（含或不含叶酸）对母亲和新生儿健康的疗效、有效性及安全性。
我们检索了Cochrane妊娠与分娩组试验注册库（2005年6月）。此外，我们联系了相关组织以识别正在进行和未发表的研究。
所有评估孕期常规补充铁剂或铁与叶酸组合效果的随机或半随机试验。
我们使用Cochrane标准评估试验的方法学质量。两位作者独立评估试验是否纳入，一位作者提取数据。我们收集了关于随机化方法、分配隐藏、盲法和失访的信息。主要结局包括母婴临床和实验室结局。
本综述纳入了40项试验，涉及12706名女性。总体而言，结果显示在大多数预先设定的结局中存在显著异质性。包括质量评估在内的标准敏感性分析无法解释异质性；因此，所有结果均采用随机效应模型进行分析。纳入试验中与母婴临床结局相关的信息非常有限。数据表明，孕期每日补充铁剂可使产妇产前和产后血液中的血红蛋白水平升高。由于研究之间存在显著异质性，难以量化这种升高。按照当前的截断值定义，接受每日产前铁剂补充的女性足月时缺铁和缺铁性贫血的可能性较小。每日补充铁剂的女性副作用和血液浓缩更为常见。每日和每周补充铁剂在妊娠期贫血方面无明显差异；每周方案在孕期血液浓缩似乎不太常见。血红蛋白大于130 g/L定义的血液浓缩的临床意义仍不确定。
需要进一步研究来评估孕期常规补充铁剂或铁与叶酸组合对母婴重要临床结局的影响。
