WHO defines puerperal sepsis as infection of the genital tract occurring at any time between the onset of the rupture of membranes or labour and the 42nd day post partum in which fever and one or more of the following are present: pelvic pain, abnormal vaginal discharge, abnormal odour of discharge, and delay in the rate of reduction of size of the uterus.15
The term maternal sepsis is used in this Review to include all infections in the same period.
Most estimates of puerperal sepsis in sub-Saharan Africa come from retrospective studies of maternal deaths, without microbiological investigation. Thus, these data reflect the burden of clinically defined puerperal sepsis as a cause of death, rather than the actual incidence (cases per live births) of puerperal sepsis or other important infections in the population.
A 2006 WHO systematic review of the causes of maternal deaths worldwide16
estimated that 9·7% (95% CI 6·3–12·6) of maternal deaths in Africa were due to puerperal sepsis. The datasets (since 1990) were selected to be representative of their populations and selected by methodological quality against predetermined criteria. Nine studies from Africa were included, and eight of these were from sub-Saharan Africa. All concerned a single country or region, retrospectively reviewing maternal deaths,17-23
except one, which was a multinational, prospective, population-based study in six countries in west Africa recruiting and following up 19 545 pregnant women.24
In this study, maternal deaths were followed up by analysis of medical records and by verbal autopsy. Six maternal deaths were attributed to sepsis, accounting for 10·9% of all maternal deaths or 33·9 (12·4–73·8) deaths per 100 000 live births.24
The wide CIs reflect the difficulty of using maternal death as a prospective outcome, even in a multinational study. Retrospective case reviews, however, are hampered by poor documentation and limited investigations, which reduce the accuracy of these reports. Many maternal deaths are unrecorded, particularly if delivery occurs outside of a hospital.
Since the WHO systematic review, a South African confidential enquiry25
into maternal deaths (representative of the population it described) reported puerperal sepsis as the cause of 8·3% (274) of deaths (2002–04). The diagnosis of puerperal sepsis was separated from non-pregnancy related infections, which accounted for 23·0% (130) of maternal deaths in 1998,21
increasing to 37·8% (1246) of maternal deaths in 2002–04.25
Of these deaths, 53·1% (662) were attributed to HIV/AIDS, 25·4% (316) to pneumonia, 8·3% (104) to tuberculosis, and 6·3% (79) to meningitis. Diagnoses were clinical, rather than from systematic microbiological investigation.
An important recent study comes from a tertiary facility in Mozambique;26
although not population-based (referral centre), it is included here as the first prospective study in sub-Saharan Africa to use autopsy and histology to determine the cause of maternal death. From 139 autopsies, 14 (10·1%) were puerperal or post-caesarean sepsis. Additionally, 67 (48·2%) deaths were from other infectious diseases (). Using the data from this study, a retrospective review has since been carried out to assess the correlation between autopsy (used as gold-standard for cause of death) and prior clinical diagnosis of maternal cause of death. The highest rates of false-negative clinical diagnoses were for infectious diseases, with sensitivities under 50%. Hypertensive disorders (eclampsia) were the main false-positive diagnoses.36
All of the other studies of maternal mortality described above are based on diagnoses of maternal death from clinical records or verbal autopsy only. Although the study from Mozambique is a single-site tertiary-referral centre and the results cannot necessarily be extrapolated across sub-Saharan Africa, it does suggest that there might be substantial inaccuracies in the available data on causes of maternal mortality, particularly under-reporting of infection as a cause of death.36
Summary of maternal morbidity data
Data on maternal morbidity in sub-Saharan Africa are very limited. summarises those studies providing data on maternal morbidity from puerperal sepsis, or providing microbiological and histological data. These studies mainly comprise retrospective case reviews, facility based studies,27,28
or studies with substantial missing data.35
Some of the best evidence comes from the multinational, prospective, population-based study from west Africa, described above,30
which includes data on maternal morbidity and puerperal sepsis—19 545 women were actively followed up post partum.30
18 cases of puerperal sepsis were identified, representing a maternal morbidity ratio of 90 (50–140) per 100 000 live births. The six patients that died represented a case fatality ratio of 33%.
Estimates of the prevalence of maternal sepsis also come from intervention studies. Three clinical trials in sub-Saharan Africa intervened to reduce puerperal sepsis. A single facility-based trial in Malawi32
used manual antiseptic cleansing of the birth canal at vaginal examination, and wiping of the newborn at delivery. Post partum infection was diagnosed clinically after delivery, or if women re-presented (passive follow-up). Six (5·6%) of 107 women who delivered in the intervention period, compared with 17 (12·7%) of 134 women who delivered in the non-intervention period were diagnosed with puerperal sepsis.
The second study was a double-blind randomised controlled trial in two facilities in Durban, South Africa,31
among women infected with HIV in whom vaginal delivery was expected. A single dose of intravenous cefoxitin or placebo was given during birth, with follow up for signs of any infectious morbidity at 72 h, 1 week, and 2 weeks. Overall there was no significant difference in symptoms suggestive of puerperal sepsis, although cefoxitin significantly reduced endometritis.
The third study was community-based in ten surveillance sites across two rural districts of Mwanza, Tanzania,34
involving the provision of a clean delivery kit and maternal education on hygienic delivery. Allocation was dependent on maternal choice rather than randomisation; puerperal sepsis up to 5 days post partum was diagnosed in 1·1% (19) of women who used the kit and 3·6% (50) who did not.
It is clear that a single, reliable estimate of the incidence of puerperal sepsis in sub-Saharan Africa cannot be made. However, the available evidence suggests that infections around childbirth substantially contribute to maternal morbidity, are underestimated, are a leading cause of death in mothers in sub-Saharan Africa, and are more frequent in hospital-based deliveries than in the community. It is apparent that future studies should look at the morbidity and mortality from both puerperal sepsis and maternal sepsis not thought to be directly related to delivery, and should use adequate microbiological investigations.