Methods of milk expression for lactating women

 

Abstract

Background

This is an update of a 2008 Cochrane review. Breastfeeding is important. However, not all infants can feed at the breast and methods of expressing milk need evaluation.

Objectives

To assess acceptability, effectiveness, safety, effect on composition, contamination and cost implications of methods of milk expression.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 January 2011), CINAHL (1982 to January 2011), conference proceedings, secondary references and contacted researchers.

Selection criteria

Randomised and quasi-randomised trials comparing methods at any time after birth, and crossover trials commencing at least 28 days after birth.

Data collection and analysis

Three authors independently assessed trials, extracted data and assessed risk of bias. Data were checked for accuracy.

Main results

We included 23 studies with 10 studies (632 mothers) providing data for analysis.

Mothers provided with a relaxation tape produced more milk than mothers who were not (mean difference (MD) 34.70 ml/single expression, 95% confidence interval (CI) 9.51 to 59.89, P = 0.007). A lower milk volume over six days was reported when comparing hand expression to the electric pump (standardised mean difference (SMD) -1.00 ml, 95% CI -1.64 to -0.36, P = 0.002); other studies of the same pump using different measures did not find a significant difference (12 to 36 hours postpartum SMD -0.38 cc, 95% CI -0.86 to 0.10, P = 0.12); day five postpartum SMD -0.62 ml/day, 95% CI -1.43 to 0.19, P = 0.13). No evidence of difference in volume was found with simultaneous or sequential pumping, or between manual and electric pumps studied. One study reported a higher sodium concentration in hand expressed milk compared to a manual pump (SMD 0.59 mmol/L, 95% CI 0.22 to 0.96, P = 0.002) and to an electric pump (SMD 0.70 mmol/L, 95% CI 0.32 to 1.09, P = 0.0003), and lower potassium concentration compared to a manual pump (MD -0.37 mmol/L, 95% CI 0.00 to 0.73, P = 0.05) or to an electric pump (SMD -0.32 mmol/L, 95% CI -0.69 to 0.06, P = 0.10). No evidence of difference was found for energy content, milk contamination or adverse effects. Reports of maternal views were not comparable. Economic aspects were not reported.  

Authors' conclusions

The most suitable method for milk expression may depend on the time since birth, purpose of expression and the individual mother and infant. Low cost interventions including early initiation when not feeding at the breast, relaxation, hand expression and lower cost pumps may be as effective, or more effective, than large electric pumps for some outcomes. Small sample sizes, large standard deviations, small number of studies reviewed, and the diversity of the interventions argue caution in applying these results beyond the specific method tested in the specific settings.

 

Plain language summary

Methods of milk expression for lactating women

Babies who do not receive human milk are more likely to suffer health problems as newborns and later. Not all babies are able to feed at the breast because they are premature, ill or separated from their mothers; thus expressed milk is needed. Mothers may express milk for their own comfort, to increase supply, or to leave milk for their baby. This updated review includes 23 randomised controlled studies with 10 (632 mothers) providing data for analysis. It includes mothers of infants in neonatal units in the USA, UK, Malaysia, Brazil, Egypt, Kenya and Nigeria, as well as term infants in the USA and UK. A greater milk volume was associated with providing a relaxation tape (one study), and when the mothers made an earlier start after birth of expressing milk for an infant unable to breastfeed. In another study, a large electric pump provided a greater mean volume of milk than hand expression over six days in the first two weeks after birth, though a greater volume was not found in two other studies of the same pump looking at 12 to 36 hours postpartum or on day five. No difference in volume was evident between the manual and electric pumps studied or with single versus double pumping. Sodium concentration was found to be higher in hand expressed milk, which may be important for preterm infants. Any milk contamination was similar comparing hand-expressed and pumped milk, and the level of maternal breast or nipple pain was no different between methods. All studies were small and results may not apply to pumps other than those tested or in different situations. No study asked mothers if they had achieved their own goals for expressing. None of the studies examined costs involved with methods. Twelve of the 18 studies that evaluated pumps or products had support from the manufacturers. The available evidence indicates that low-cost measures such as early initiation of expressing for an infant unable to breastfeed, relaxation, hand expression, and lower cost pumps may be as effective, or more effective, than large electric pumps for some outcomes. Not all the studies mentioned whether basic supports were provided, particularly for mothers with hospitalised children, including access to food and fluid, a place to rest near their baby, and the availability of knowledgeable health workers. These supports could affect milk expression.

 

摘要

背景

哺乳婦女的擠乳方法

母乳哺育對健康很重要，不過，並非所有的嬰兒都可以用乳房哺餵，目前並未對有效的擠乳方法進行適當地評估。

目標

評估各種擠乳方式(包括手擠和人工式、電池式或插電式擠乳器)的接受度、效果、安全性、對母乳成份的影響、細菌污染情況與費用負擔。

搜尋策略

我們搜尋Cochrane Pregnancy和Childbirth Group's Trials Register (2007年12月)、CINAHL (1982年2007年7月)，以人工方式搜尋相關期刊與研討會紀錄，並掃描參考文獻與連絡該領域的專家。

選擇標準

比較產後任何時間、各種擠乳方式或技術的隨機與準半隨機控制試驗(quasirandomised controlled trials)，以及產後至少28天後才開始的交叉試驗(crossover trials)。

資料收集與分析

2位作者獨立評估試驗品質與選用資料。我們聯絡試驗作者以獲得其他資料。

主要結論

12個研究符合納入標準，其中6個研究(397名母親)提供的資料可用來進行分析。相較於用手擠乳，一個研究發現使用電動擠乳器(373.10 ml, 95% 信賴區間為161.09 – 585.11)和腳踩擠乳器(212.10 ml, 95% 信賴區間為 9.39 – 414.81)在6天後的總乳量顯著較多；不過，電動擠乳器和腳踩擠乳器之間的差異並不顯著。聆聽放鬆音樂的母親的擠乳量比未聽音樂之婦女多(34.70 ml, 95% 信賴區間為9.51 – 59.89)。一個研究發現兩側乳房同時擠乳花的時間比連續擠乳少(3.50小時/週, 95% 信賴區間為1.39 – 5.61)。沒有證據顯示兩側乳房同時擠乳和連續擠乳的擠乳量及使用不同擠乳方法所導致母乳污染、出院時哺餵母乳、母乳中脂肪含量、血清泌乳激素有所差異。缺乏各種擠乳方法相關母親滿意度、不良反應和經濟影響的報告。

作者結論

產後6天內產婦使用電動或腳動幫浦擠乳可以比用手擠乳獲得較多的乳量，產後第2週聆聽放鬆音樂也可以增加一次擠乳量。兩側乳房同時擠乳花的時間比連續擠乳少。需要有更多樣本和更廣泛報告的研究來探討，母親擠乳的動機和她們對擠乳效果的評估有關，而非關於擠乳用具性功能的研究。

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

哺乳婦女的擠乳方法：世界衛生組織建議嬰兒在出生到6個月以純母乳。未接受母乳哺育的孩童比較可能有健康問題。並非所有嬰兒都可以用乳房親餵，不能親餵的原因包括早產、疾病、異常或和母親分開， 因此就需要擠乳提供給這些嬰兒。母親也可能因為乳頭疼痛(sore nipples)或乳房腫脹(engorgement)而須擠乳以使自己感到舒適；或是為了增加乳量或把母乳留給不在身旁的嬰兒。擠乳的可能副作用包括母親受傷和可能影響胎兒的細菌感染。此文獻回顧包括12個研究，其中6個研究的資料可納入分析。這6個試驗裡的所有母親的嬰兒都住在新生兒病房，研究地點包括美國、英國、馬來西亞、肯亞與奈及利亞。一個研究發現在產後2週內連續6天使用電動式或腳踩式擠乳器可以比用手擠乳獲得更多的乳量。兩側乳房同步時擠乳和連續擠乳獲得的量差不多，不過所費時間有差。另一個研究中發現聆聽放鬆音樂的母親獲得的擠乳量較多。一個小型研究發現，用手擠乳和幫浦擠乳的母乳污染發生率差不多。因為所有的研究都是小型研究，所以結果可能無法運用到其他未檢測的幫浦擠乳器。沒有研究詢問哺乳婦女是否有達到自己的擠乳目的，也沒有研究檢視各種方法的花費，而且10個研究中有8個研究是由製造商贊助。現有的證據顯示，低花費的方法如放鬆、乳房按摩、增加擠乳頻率和兩側同步擠乳，可以幫助供乳。並非所有研究都有提到是否有提供基礎支持，特別是孩童住院的母親們，這些支持包括飲食之取得、病房接近嬰兒房、有充分知識的照護者。不論使用哪種擠乳方式，都需讓母親們感覺受到尊重與獲得支持。