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Intervention Review

Effects and safety of preventive oral iron or iron+folic acid supplementation for women during pregnancy

  1. Juan Pablo Peña-Rosas1,*,
  2. Fernando E Viteri2

Editorial Group: Cochrane Pregnancy and Childbirth Group

Published Online: 7 OCT 2009

Assessed as up-to-date: 24 JUN 2009

DOI: 10.1002/14651858.CD004736.pub3

How to Cite

Peña-Rosas JP, Viteri FE. Effects and safety of preventive oral iron or iron+folic acid supplementation for women during pregnancy. Cochrane Database of Systematic Reviews 2009, Issue 4. Art. No.: CD004736. DOI: 10.1002/14651858.CD004736.pub3.

Author Information

  1. 1

    World Health Organization, Reduction of Micronutrient Malnutrition Unit, Department of Nutrition for Health and Development, Geneva 27, Switzerland

  2. 2

    Children's Hospital and Oakland Research Institute, Oakland, CA, USA

*Juan Pablo Peña-Rosas, Reduction of Micronutrient Malnutrition Unit, Department of Nutrition for Health and Development, World Health Organization, 20 Avenue Appia, Geneva 27, 1211, Switzerland. penarosasj@who.int.

Publication History

  1. Publication Status: New search for studies and content updated (no change to conclusions)
  2. Published Online: 7 OCT 2009

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This is not the most recent version of the article. View current version (12 DEC 2012)

 

Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Background

Intake of supplements containing iron or a combination of iron and folic acid by pregnant women may improve maternal health and pregnancy outcomes. Recently, intermittent supplementation regimens have been proposed as alternatives to daily regimens.

Objectives

To assess the effectiveness and safety of daily and intermittent use of iron or iron+folic acid supplements by pregnant women.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2009) and contacted relevant organisations for the identification of ongoing and unpublished studies.

Selection criteria

All randomised or quasi-randomised trials evaluating the effect of supplementation with iron or iron+folic acid during pregnancy.

Data collection and analysis

We assessed the methodological quality of trials using the standard Cochrane criteria. Two authors independently assessed which trials to include in the review and one author extracted data.

Main results

We included 49 trials, involving 23,200 pregnant women. Overall, the results showed significant heterogeneity across most prespecified outcomes and were analysed assuming random-effects. The trials provided limited information related to clinical maternal and infant outcomes.

Overall, daily iron supplementation was associated with increased haemoglobin levels in maternal blood both before and after birth and reduced risk of anaemia at term. These effects did not differ significantly between women receiving intermittent or daily iron or iron+folic acid supplementation. Women who received daily prenatal iron supplementation with or without folic acid were less likely to have iron deficiency at term as defined by current cut-off values than those who received no treatment or placebo. Side effects and haemoconcentration (a haemoglobin level greater than 130 g/L) were more common among women who received daily iron or iron+folic acid supplementation than among those who received no treatment or placebo. The risk of haemoconcentration during the second and third trimester was higher among those on a daily regimen of iron supplementation. The clinical significance of haemoconcentration remains uncertain.

Authors' conclusions

Universal prenatal supplementation with iron or iron+folic acid provided either daily or weekly is effective to prevent anaemia and iron deficiency at term. We found no evidence, however, of the significant reduction in substantive maternal and neonatal adverse clinical outcomes (low birthweight, delayed development, preterm birth, infection, postpartum haemorrhage). Associated side effects and particularly haemoconcentration during pregnancy may suggest the need for revising iron doses and schemes of supplementation during pregnancy and adjust preventive iron supplementation recommendations.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Effects and safety of preventive oral iron or iron+folic acid supplementation for women during pregnancy

Preventive daily or intermittent iron or iron+folic acid supplementation taken by women during pregnancy reduces anaemia and iron deficiency in mothers. There is evidence that taking iron or iron and folic acid daily or intermittently has a similar effect in reducing anaemia at term and improving haemoglobin concentrations in the mother. Daily iron or iron and folic acid is associated with adverse side effects.

During pregnancy, women need iron and folate to meet their own needs and those of their developing fetus. There is concern that pregnant women may become deficient in these nutrients and unable to supply them in sufficient quantities to their fetus. Low iron and folate levels in women can cause anaemia, and low folate periconceptionally increases the risk of neural tube defects (NTD). Anaemia can make women tired, faint, and at increased risk for infection. Iron and folate deficiencies could impact the mother and her pregnancy, and the baby. In this review of 49 trials, involving 23,200 pregnant women, we found data to conclude that the use of iron or iron+folic acid supplements was associated with a reduced risk of anaemia and iron deficiency in pregnancy and that daily iron supplementation was associated with increased risk of haemoconcentration at term. The effects of iron or iron+folic acid on reducing anaemia and iron deficiency anaemia at term were similar whether the supplements were taken daily or weekly. More research is needed on the safe and effective amounts of iron and schemes to provide in preventive supplementation programs for pregnant women on functional outcomes, particularly in low-income countries.

 

摘要

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

背景

預防性口服鐵質或鐵質加葉酸補充品對孕婦的效果與安全性

孕婦服用含鐵質或鐵質加葉酸的補充品,或許可以改善母體健康和懷孕預後。最近,有人提出以間歇性補充來替代每日補充。

目標

評估孕婦每天和間歇性使用鐵質或鐵質加葉酸的效果與安全性。

搜尋策略

我們搜尋Cochrane Pregnancy和Childbirth Group's Trials Register (2009年3月)以及聯絡相關機構,以區別進行中的和未發表的研究。

選擇標準

評估懷孕期間補充鐵質或鐵質加葉酸的所有隨機或半隨機試驗。

資料收集與分析

我們使用Cochrane之標準規範來評估試驗的方法品質,2位作者獨立評估哪些試驗可納入回顧,1位作者摘錄資料。

主要結論

共納入49篇試驗、23,200名孕婦。整體而言,結果顯示在多數預先定義的預後之間有明顯的異質性,因此採用隨機效果模式來進行分析。試驗提供有關臨床母嬰預後的資訊有限。整體而言,每天補充鐵質和增加母親產前與產後血紅素值有關,且減少生產時之貧血風險。在間歇性或每日服用鐵質或鐵質加葉酸的婦女之間,這些效果並無顯著差異。相較於沒有接受治療或使用安慰劑者,產前每天服用鐵質補充品的婦女,不論有無加葉酸,都比較不會在生產時缺鐵(根據現有的數值定義)。相較於沒有接受治療或使用安慰劑者,副作用和血液濃稠(血紅素值大於130 g/L)在每日服用鐵或鐵加葉酸組比較常見。每天服用鐵質補充品的婦女,第2和第3懷孕期的血液濃稠之風險較高。但血液濃稠所扮演的臨床意義還不清楚。

作者結論

產前普遍在使用的鐵質或鐵質加葉酸之補充品,不論是每天或每週服用,都可有效預防生產時之貧血和缺鐵。不過,我們發現,並無證據顯示可顯著減少後續母親及嬰兒的不良臨床預後(低出生體重、發育延遲、早產、感染、產後出血)。相關的副作用,特別是懷孕期間引起血液濃稠,可能代表需調整懷孕期間鐵劑劑量以及給藥時間,而且可能代表需要修正預防性鐵質補充之建議。

翻譯人

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

懷孕期間預防性口服鐵質或鐵質加葉酸的安全性與效果。 孕婦預防性服用鐵質或鐵質加葉酸,不論是間歇性或每日服用,都可減少孕婦的貧血和缺鐵。證據顯示,間歇性或每日服用鐵質或鐵質加葉酸,對於減少母親生產時之貧血和改善血紅素值的效果相當。每日服用鐵質或鐵質加葉酸與副作用有關。 懷孕期間,婦女需要鐵質和葉酸來滿足自己和胎兒的需求。因此後有此擔心,孕婦可能會缺乏這些物質,而無法提供足夠的量給胎兒。婦女低鐵和低葉酸會引起貧血,受孕前後時之低葉酸會增加神經管缺陷(neural tube defects (NTD))之風險。貧血會造成孕婦感到疲倦、虛弱,且會增加感染風險。鐵和葉酸的缺乏會影響婦女和懷孕,也會影響胎兒。本次回顧49篇試驗、23,200名孕婦,我們發現,使用鐵質或鐵質加葉酸之補充品可減少懷孕時之貧血和缺鐵,另外每天補充鐵質和生產時之血液濃稠風險增加有關。不論是每天或每週服用,鐵質或鐵質加葉酸減少生產時之貧血和缺鐵性貧血的效果相似。需要更多研究探討鐵質劑量和給藥時間的安全性和效果,以提供孕婦有關功能性預後的預防性補充計畫,特別是低收入國家。