Antibiotic prophylaxis versus no prophylaxis for preventing infection after cesarean section

 

Abstract

Background

The single most important risk factor for postpartum maternal infection is cesarean section. Routine prophylaxis with antibiotics may reduce this risk and should be assessed in terms of benefits and harms.

Objectives

To assess the effects of prophylactic antibiotics compared with no prophylactic antibiotics on infectious complications in women undergoing cesarean section.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009).

Selection criteria

Randomized controlled trials (RCTs) and quasi-RCTs comparing the effects of prophylactic antibiotics versus no treatment in women undergoing cesarean section.

Data collection and analysis

Two authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction.

Main results

We identified 86 studies involving over 13,000 women. Prophylactic antibiotics in women undergoing cesarean section substantially reduced the incidence of febrile morbidity (average risk ratio (RR) 0.45; 95% confidence interval (CI) 0.39 to 0.51, 50 studies, 8141 women), wound infection (average RR 0.39; 95% CI 0.32 to 0.48, 77 studies, 11,961 women), endometritis (RR 0.38; 95% CI 0.34 to 0.42, 79 studies, 12,142 women) and serious maternal infectious complications (RR 0.31; 95% CI 0.19 to 0.48, 31 studies, 5047 women). No conclusions can be made about other maternal adverse effects from these studies (RR 2.43; 95% CI 1.00 to 5.90, 13 studies, 2131 women). None of the 86 studies reported infant adverse outcomes and in particular there was no assessment of infant oral thrush. There was no systematic collection of data on bacterial drug resistance. The findings were similar whether the cesarean section was elective or non elective, and whether the antibiotic was given before or after umbilical cord clamping. Overall, the methodological quality of the trials was unclear and in only a few studies was it obvious that potential other sources of bias had been adequately addressed.

Authors' conclusions

Endometritis was reduced by two thirds to three quarters and a decrease in wound infection was also identified. However, there was incomplete information collected about potential adverse effects, including the effect of antibiotics on the baby, making the assessment of overall benefits and harms complicated. Prophylactic antibiotics given to all women undergoing elective or non-elective cesarean section is clearly beneficial for women but there is uncertainty about the consequences for the baby.

 

Plain language summary

Routine antibiotics at cesarean section to reduce infection

Women undergoing cesarean section have a five to 20-fold greater chance of getting an infection compared with women who give birth vaginally. These infections can be in the organs within the pelvis, around the surgical incision and sometimes the urine. The infections can be serious, and very occasionally can lead to the mother’s death. The potential benefits of reducing infection for the mother need to be balanced against adverse effects such as nausea, vomiting, skin rash and rarely allergic reactions in the mother, and the risk of thrush and any effect of antibiotics on the 'friendly' gut bacteria in the baby. This review looked at whether antibiotics are effective at elective and emergency cesarean sections. It also studied the effect of giving the antibiotics before or after the cord is clamped. The review found 86 studies involving over 13,000 women. Routine use of antibiotics at cesarean section reduced the risk of fever and of wound, womb and urine infections in mothers. It also reduced the risk of serious complications of infections for the mothers. This was so whether the cesarean section was elective or emergency, and whether the antibiotics were given before or after clamping of the umbilical cord. However, none of the studies looked properly at possible adverse effects on the baby, for example, whether its use increased the risk of thrush. Similarly, it was unclear whether the routine use of antibiotics at cesarean section would contribute to increasing drug resistant strains of bacteria. Studies are needed on these two aspects of this intervention.

 

摘要

背景

預防性抗生素使用與否對於剖腹產術後感染之預防效果

產後母親感染的唯一最重要的危險因子是剖腹產。常規的預防性抗生素使用可能可以減少這種風險，其好處及壞處應當加以評估。

目標

為了評估預防性抗生素的使用對於接受剖腹產的婦女發生感染的預防效果。

搜尋策略

我們搜尋了2009年5月的Cochrane Pregnancy and Childbirth Group's Trials Regster。

選擇標準

比較預防性抗生素使用與否對於接受剖腹產的婦女發生感染的預防效果之隨機對照試驗 (randomized controlled trials, RCTs)和準隨機對照試驗 (quasiRCTs) 。

資料收集與分析

兩位作者獨立地評估研究是否納入及研究偏差的風險，並進行數據摘提。

主要結論

我們收集了包含1萬3千名婦女的86個研究。預防性應用抗生素的婦女接受剖腹產的發病率大大降低了產後發燒的發生率(平均風險比(RR)0.45; 95％可信區間(CI)0.39至0.51，50個研究，8141名婦女)，傷口感染率(平均風險比: 0.39; 95％信賴區間 0.32至0.48，77個研究，11961名婦女)，子宮內膜炎發生率(RR 0.38，95％CI 為 0.34至0.42，79個研究，12142名婦女)和產婦發生嚴重感染併發症的機會(RR 0.31，95％CI 為 0.19至0.48，31個研究，5047婦女)。這些研究中，抗生素對產婦的其他不良影響沒有結論RR 2.43，95％CI 為 1.00～5.90，13項研究，2131名婦女。在86個研究中也沒有報告嬰兒有不良反應，特別是有沒有嬰兒鵝口瘡的評估報告。研究中亦沒有系統地收集細菌抗藥性的數據。研究結果顯示在選擇性或緊急剖腹產手術，在夾住臍帶之前或之後給予抗生素的效果是類似的。總體而言，研究方法的品質上並不清楚，只有少數研究清楚地指出潛在的偏差來源。

作者結論

預防性抗生素的使用減少了三分之二至四分之三的子宮內膜炎，也減少了傷口感染的發生。然而，對於潛在的不良影響，包括抗生素使用對嬰兒的影響，並沒有完整的資料收集，使得整體利益和損害的評估變得複雜。預防性抗生素對所有接受選擇性或緊急剖腹產的婦女顯然是有益的，但對嬰兒的影響則不確定。

翻譯人

本摘要由屏東基督教醫院趙珮娟翻譯。

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

總結

常規抗生素的使用對於減少剖腹產感染：婦女接受剖腹產發生感染的機會為自然產的5至20倍。這些感染可發生在骨盆腔內的器官,手術傷口周圍，或尿路感染。感染程度可以很嚴重，少數時候會導致母親的死亡。使用抗生素以減少感染的潛在好處需和其不利影響相權衡，如母親發生噁心，嘔吐，皮膚紅疹，少數會有過敏反應，鵝口瘡，影響嬰兒腸道中的 ‘好菌’ 。這一篇回顧探討抗生素的使用對預防選擇性和緊急剖腹產手術感染是否有效，並且研究了的效果。回顧包含1萬3千名婦女的86個研究發現常規使用抗生素降低剖腹產後發燒，傷口'子宮及尿路感染的風險，也減少了母親併發嚴重感染的風險。不管是選擇性或緊急剖腹產手術，在夾住臍帶之前或之後給予抗生素皆有此效果。但是，沒有研究探究使用抗生素對嬰兒可能產生的不利影響，例如是否增加了發生鵝口瘡的風險，也不清楚在剖腹產時常規使用抗生素是否和抗藥性菌株的增加有關。在這兩方面的影響需要進一步的研究。