Intervention Review

You have free access to this content

Intermittent oral iron supplementation during pregnancy

  1. Juan Pablo Peña-Rosas1,*,
  2. Luz Maria De-Regil1,
  3. Therese Dowswell2,
  4. Fernando E Viteri3

Editorial Group: Cochrane Pregnancy and Childbirth Group

Published Online: 11 JUL 2012

Assessed as up-to-date: 12 JUN 2012

DOI: 10.1002/14651858.CD009997


How to Cite

Peña-Rosas JP, De-Regil LM, Dowswell T, Viteri FE. Intermittent oral iron supplementation during pregnancy. Cochrane Database of Systematic Reviews 2012, Issue 7. Art. No.: CD009997. DOI: 10.1002/14651858.CD009997.

Author Information

  1. 1

    World Health Organization, Evidence and Programme Guidance, Department of Nutrition for Health and Development, Geneva, Switzerland

  2. 2

    The University of Liverpool, Cochrane Pregnancy and Childbirth Group, Department of Women's and Children's Health, Liverpool, UK

  3. 3

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

*Juan Pablo Peña-Rosas, Evidence and Programme Guidance, Department of Nutrition for Health and Development, World Health Organization, 20 Avenue Appia, Geneva, 1211, Switzerland. penarosasj@who.int.

Publication History

  1. Publication Status: New
  2. Published Online: 11 JUL 2012

SEARCH

 

Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要
  5. 淺顯易懂的口語結論

Background

Anaemia is a frequent condition during pregnancy, particularly among women from developing countries who have insufficient iron intake to meet increased iron needs of both the mother and the fetus.Traditionally, gestational anaemia has been prevented with the provision of daily iron supplements throughout pregnancy, but adherence to this regimen due to side effects, interrupted supply of the supplements, and concerns about safety among women with an adequate iron intake, have limited the use of this intervention. Intermittent (i.e. one, two or three times a week on non-consecutive days) supplementation with iron alone or in combination with folic acid or other vitamins and minerals has recently been proposed as an alternative to daily supplementation.

Objectives

To assess the benefits and harms of intermittent supplementation with iron alone or in combination with folic acid or other vitamins and minerals to pregnant women on neonatal and pregnancy outcomes.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 March 2012). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) for ongoing studies and contacted relevant organisations for the identification of ongoing and unpublished studies (23 March 2012).

Selection criteria

Randomised or quasi-randomised trials.

Data collection and analysis

We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy.

Main results

This review includes 21 trials from 13 different countries, but only 18 trials (with 4072 women) reported on our outcomes of interest and contributed data to the review. All of these studies compared daily versus intermittent iron supplementation.

Three studies provided iron alone, 12 iron+folic acid and three more iron plus multiple vitamins and minerals. Their methodological quality was mixed and most had high levels of attrition. Overall, there was no clear evidence of differences between groups for infant primary outcomes: low birthweight (average risk ratio (RR) 0.96; 95% confidence interval (CI) 0.61 to 1.52, seven studies), infant birthweight (mean difference MD -8.62 g; 95% CI -52.76 g to 35.52 g, eight studies), premature birth (average RR 1.82; 95% CI 0.75 to 4.40, four studies). None of the studies reported neonatal deaths or congenital anomalies.

For maternal outcomes, there was no clear evidence of differences between groups for anaemia at term (average RR 1.22; 95% CI 0.84 to 1.80, four studies) and women receiving intermittent supplementation had less side effects (average RR 0.56; 95% CI 0.37 to 0.84, 11 studies) than those receiving daily supplements. Women receiving intermittent supplements were also at lower risk of having high haemoglobin (Hb) concentrations (greater than 130 g/L) during the second or third trimester of pregnancy (average RR 0.48; 95% CI 0.35 to 0.67, 13 studies). There were no significant differences in iron-deficiency anaemia between women receiving intermittent or daily iron+folic acid supplementation (average RR 0.71; 95% CI 0.08 to 6.63, 1 study). There were no maternal deaths (six studies) or women with severe anaemia in pregnancy (six studies). None of the studies reported on iron deficiency at term or infections during pregnancy.

Where sufficient data were available for primary outcomes, we set up subgroups to look for possible differences between studies in terms of earlier or later supplementation; women's anaemia status at the start of supplementation; higher and lower weekly doses of iron; and the malarial status of the region in which the trials were conducted. There was no clear effect of these variables on the results of the review.

Authors' conclusions

The present systematic review is the most comprehensive summary of the evidence assessing the benefits and harms of intermittent iron supplementation regimens in pregnant women on haematological and pregnancy outcomes. The findings suggest that intermittent iron+folic acid regimens produce similar maternal and infant outcomes at birth as daily supplementation but are associated with fewer side effects. Women receiving daily supplements had increased risk of developing high levels of Hb in mid and late pregnancy but were less likely to present mild anaemia near term. Although the evidence is limited and the quality of the trials was low or very low, intermittent may be a feasible alternative to daily iron supplementation among those pregnant women who are not anaemic and have adequate antenatal care.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要
  5. 淺顯易懂的口語結論

Intermittent regimens of iron supplementation during pregnancy

Anaemia is a frequent condition during pregnancy, particularly among women from developing countries who have insufficient iron intake to meet increased iron needs. Traditionally, pregnancy anaemia has been prevented with the provision of daily iron supplements, however, it has recently been proposed that if women take supplements less often, such as once or twice weekly rather than daily, this might reduce side effects and increase acceptance and adherence to supplementation. In this review we assess the benefits and harms of intermittent (i.e. one, two or three times a week on non-consecutive days) oral supplementation with iron or iron+folic acid or iron+vitamins and minerals for pregnant women.

We included 21 randomised controlled trials, but only 18 trials involving 4072 women, had information on the outcomes we evaluated. Three studies looked at intermittent iron alone versus daily iron alone; there did not appear to be differences in the effects of two types of regimens when women were followed up.The other studies included in the review compared intermittent iron+folic acid versus daily iron+folic acid. Two of these studies looked at intermittent versus daily iron+folic acid in women who were also advised to take daily calcium supplements.There was no clear evidence of differences between groups for most of the outcomes we examined including infant birthweight, premature birth, perinatal death, and anaemia, haemoglobin concentration and iron deficiency in women at the end of pregnancy. However, women receiving intermittent rather than daily iron supplements were less likely to report side effects (such as constipation and nausea). In addition, intermittent supplementation appeared to decrease the number of women with high haemoglobin concentrations during mid and late pregnancy compared with daily regimens. High haemoglobin concentrations may be harmful as they may be associated with an increased risk of having a premature birth and low birthweight baby. There were no other clear differences between groups for other outcomes examined.

 

摘要

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要
  5. 淺顯易懂的口語結論

懷孕期間週期性口服鐵劑補充

背景

貧血是懷孕期間常見問題,特別是發展中國家婦女,有鐵攝取不足以滿足母親與胎兒增加的鐵質需求的問題。傳統上,妊娠期貧血利用孕期每日的鐵劑補充以避免,但因為副作用、中斷補品供應而無法遵從此療法、以及有適當攝取鐵質婦女在使用此療法的安全性考量,限制了此介入的採用。週期性 (例如:一周1、2或3次,非連續天)的單獨補充鐵,或是結合葉酸或其他維生素與礦物質,已近來被提出可做為每日補充品之另一個替代選擇。

目的

評估懷孕婦女週期性的單獨補充鐵劑,或是劑結合葉酸或其他維生素與礦物質一起服用時,對新生兒與懷孕結果上的利弊。

搜尋策略

我們搜尋了考科藍孕期與出生群組的試驗註冊資料庫 (2012年3月23日)。我們也搜尋了WHO國際臨床試驗註冊平台(ICTRP)查詢進行中的研究,並連絡相關機構找出進行中且未公開的研究(2012年3月23日)。

選擇標準

隨機化或準隨機化試驗。

資料收集與分析

我們評估了採用考科藍標準( criteria)的試驗方法論品質。兩位審閱作者獨立評估試驗的合格性、節錄數據並執行精確度的檢核。

主要結果

此審閱包含了來自13個不同國家的21個試驗,但僅有18個試驗(有4072名女性)於我們有符合本次之審閱。所有這些研究都比較了每天與週期性的鐵質補充。

三個研究提供了單獨補充鐵質、12鐵質+葉酸以及另外三種鐵質加上多種維生素與礦物質。它們的方法論品質是混合的,且大多數皆有高度的消耗水準。整體而言,就嬰兒的重要成果而言,各組間並沒有明確的差異證據: 低出生體重(平均風險比 (RR) 0.96; 95% 信賴區間(CI) 0.61到1.52,7個研究),嬰兒出生體重 (平均數差異 MD -8.62 g; 95% CI -52.76 g到35.52 g,8個研究),早產 (平均RR 1.82; 95% CI 0.75 到4.40,4個研究)。這些研究都沒有報告新生兒死亡或先天性畸形。

就母親的結果而言,各組間沒有明確差異可證實在懷孕達足月時的貧血問題(平均RR 1.22; 95% CI 0.84到1.80,4個研究),且週期性接受補充品的婦女較每天接受補充品的婦女產生的副作用較少(平均RR 0.56; 95% CI 0.37到0.84,11個研究)。週期性接受補充品的婦女在第二或第三個孕期時產生高血紅素(Hb)濃度(大於130 g/L)的風險也較低(平均RR 0.48; 95% CI 0.35到0.67,13個研究)。接受週期性鐵+葉酸補充或每日鐵+葉酸補充的婦女間在缺鐵貧血上並沒有顯著的差異(平均RR 0.71; 95% CI 0.08到6.63,1個研究)。沒有母親死亡(6個研究)或孕期中貧血嚴重的婦女(6個研究)。沒有研究報告在孕期達足月後有缺鐵或感染的情形。

於可取得重要結果的充分數據之處,我們設定子群組以尋找研究間的可能差異:包括(1)於較早或稍晚進行補充鐵劑異; (2)補充初期的婦女貧血狀況; (3)每周較高或較低劑量之鐵劑;(4)以及執行試驗區域的瘧疾狀況。 這些變數在審閱結果上沒有明確的影響。

作者結論

目前之系統性審閱是最完善的證據概要,評估懷孕婦女週期性補充鐵劑之療法在血液學與懷孕結果上的利弊。研究的發現顯示,週期性的鐵+葉酸療法與每日鐵+葉酸補充對於母親與新生嬰兒的結果類似,但週期性補充的副作用較少。接受每日補充的婦女在懷孕中期與後期產生高Hb值的風險增加,但接近足月時較可能不會出現輕微貧血。雖然證據受限且試驗的品質低或非常低,在沒有貧血且有適當產前照顧的婦女中,週期性補充或可成為每日補鐵的彈性替代。

 

淺顯易懂的口語結論

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要
  5. 淺顯易懂的口語結論

懷孕期間週期性口服鐵劑補充

懷孕期間週期性補鐵方案

貧血是懷孕期間的常見情形,特別是來自發展中國家的婦女,鐵質攝取不足以滿足增加的鐵質需求。傳統上,利用每日的鐵質補充避免孕期貧血,然而,近來有人提出,若婦女較不頻繁的進行補充,像是一周一到兩次而非每日補充,此可能可以降低副作用並增加補充的接受度與尊從。在這些審閱中我們評估了懷孕婦女週期性(例如: 一周1、2或3次,非連續天)口服補充鐵或是鐵+葉酸或是鐵+維生素與礦物質的利弊。

我們包含了21個隨機對照試驗,但僅有18個,共有4072名婦女參與的試驗具有我們所評估成果相關的資訊。有3個研究觀察週期性與每日單獨補充鐵,兩種類型的效果中沒有出現差異。審閱中所包含的其他的研究比較週期性與每日補充鐵+葉酸。這些研究中,有兩個研究在觀察週期性與每日補充鐵+葉酸的婦女,也被建議補充鈣。在大多數成果中,各組間並沒有明確的差異證據,包含有我們所檢驗的嬰兒之(1)出生體重、(2)早產、(3)出生前後死亡、以及產婦懷孕後期之(1)貧血、(2)血紅素濃度與(3)缺鐵。。然而,接受週期性而非每日鐵質補充的婦女較沒有副作用(像是便秘和噁心)的情形。此外,與進行每日療法相比,週期性補充似乎降低了懷孕中期與後期高血紅素濃度的婦女人數。因為高血紅素濃度可能與早產與嬰兒出生體重低的情形有關,因此高血紅素濃度可能有害。其他所檢驗的成果中,各組間並沒有其他明確差異。

譯註

翻譯: East Asian Cochrane Alliance
翻譯補助: 台灣衛生福利部/台北醫學大學實證醫學研究中心