Antibiotic prophylaxis for caesarean section
Prophylactic use of antibiotics (regardless of regimen) in women undergoing caesarean section reduces the risk of infection-related complications and serious infection post operation. Antibiotic prophylaxis should be used in all cases of caesarean section.
RHL Commentary by Cecatti JG
1. EVIDENCE SUMMARY
The Cochrane Review entitled "Antibiotic prophylaxis for caesarean section" analysed a large number of randomized controlled trials. It found that the use of antibiotic prophylaxis in women undergoing caesarean section leads to a decreased risk of infection-related complications, including fever, endometritis, wound infection, urinary tract infection, and serious infection after caesarean section; a small reduction was also found in the mother's duration of stay in hospital. There was, however, an increased risk of certain side-effects, although they were neither serious nor consistently recorded. Regardless of the antibiotic regimen used and of the differences among populations studied, the protective effect of prophylactic antibiotics was homogeneous across all patients undergoing caesarean section (reported in the trials as being elective, non-elective, or not specified). This effect of significant reduction in postoperative infectious morbidity (by around two-thirds) leads the reviewers to recommend that antibiotic prophylaxis be provided to all woman undergoing caesarean section.
The second review entitled "Antibiotic prophylaxis regimens and drugs for caesarean section" aimed to identify the most effective antibiotic regimen for the specific purpose of decreasing infectious morbidity after caesarean section. It found that it does not matter which regimen is used. Ampicillin and first generation cephalosporins show similar effectiveness and there seems to be no justification for using any other drug with a broader spectrum or multiple drugs. These effects are similar and homogeneous for all the main outcomes measured: endometritis, febrile morbidity, wound infections and urinary tract infection. There was, however, no consensus on the optimal timing of administration and doses.
Randomized controlled trials indexed in the Cochrane Pregnancy and Childbirth Group and the Cochrane Controlled Trials Register were selected for inclusion in both the reviews. The data were then pooled and analysed following standard procedures.
As to analysis of subgroups of data, a concern may arise regarding "non-elective caesarean section". In the trials this term was applied to women in labour with or without rupture of membranes for more than six hours. It would perhaps have been interesting to have these two conditions evaluated separately. This suggestion is based on the assumption that the effect of antibiotic prophylaxis would be higher among women with prelabour rupture of membranes for more than six hours.
2. RELEVANCE TO UNDER-RESOURCED SETTINGS
2.1. Magnitude of the problem
In general, the inability of health services to offer caesarean section in non-urban under-resourced settings is seen as a problem. However, more recently, sharp increases in caesarean section rates in some developing countries, especially in Latin America, have become a major problem. Data available for Brazil show that the overall rate of caesarean section for the country as whole is 30% of all deliveries, reaching as high as 50% of all deliveries in certain provinces (1, 2). In this situation other factors including malnutrition and poor social conditions are likely to exacerbate the already higher risk of infectious morbidity and mortality associated with caesarean section. Another serious concern is the fact that a considerable number of caesarean sections are unnecessary and planned in advance, with the additional potential risk of iatrogenic prematurity.
Deciding which antibiotic is most suitable as a prophylactic for caesarean section is very important given that in some developing country settings almost half the women deliver through an abdominal incision. In such cases, in order to reduce the cost for the health system, it would be very helpful to have a simple and inexpensive recommended antibiotic regimen.
2.2. Applicability of the results
The results of this review are applicable to under-resourced settings, especially those where caesarean section rates are high. Although the review includes a dozen studies from developing countries, data from these studies have not been analysed separately. If this were done results may show not only similar results but also a higher effect in the same direction (i.e. of reducing infectious puerperal morbidity). Even considering some differences and difficulties in diagnostic criteria, the high prevalence of poor social and economic conditions, anaemia, blood loss, vaginal examinations, prelabour rupture of membranes and other pathological conditions could account for a stronger protective effect of antibiotic prophylaxis.
The recommendation to use ampicillin or first generation cephalosporin for the purpose of caesarean section antibiotic prophylaxis makes this task easier. These antibiotics are in fact the most common drugs that have been used in the past decades in developing countries.
2.3. Implementation of the intervention
The results of this review are clear in recommending antibiotic prophylaxis for all caesarean sections. The only restriction could be for elective caesarean sections in institutions in which the rates of postoperative infectious complication are very low. This, of course, is not the case of under-resourced settings.
In order to implement this recommendation some education and training of health staff would be necessary. The inclusion of this recommendation in the rules and guidelines of ministries of health and of the national societies of gynaecology and obstetrics would help in the adoption of this practice by hospitals. This knowledge should also be spread among professionals in congresses, meetings and bulletins.
The choice of antibiotic is addressed in the second review which identified ampicillin or first generation cephalosporin as the most appropriate drugs for prophylaxis. For women with a history of penicillin-allergy, clindamycin is another suitable option. These should constitute the general national recommendations for a single-dose regimen.
3. RESEARCH
The above recommendations are based on a large number of trials that found strong and clear beneficial effects of antibiotic prophylaxis for caesarean sections. Additional efforts could be concentrated on clarifying the exact role of prelabour rupture of membranes, the existence of previous vaginal and cervical infections like bacterial vaginosis, and some cost-effectiveness analysis comparing the effects of this prophylaxis with the treatment of infectious morbidity in the post-partum period. These goals should not be addressed in new trials but perhaps in secondary analysis of already available data. Another research question to be elucidated refers to the real maternal side-effects associated with this intervention.
References
- Barros FC, Vaughan JP, Victora CG, Huttly SRA. Epidemic of Caesarean sections in Brazil. The lancet 1991;338:167-169.
- Faundes A, Cecatti JG. Which policy for Caesarean section in Brazil? An analysis of trends and consequences. Health policy and planning 1991;8:33-42.
This document should be cited as: Cecatti JG. Antibiotic prophylaxis for caesarean section: RHL commentary (last revised: 18 January 2005). The WHO Reproductive Health Library; Geneva: World Health Organization.