Efforts to reduce maternal mortality in Africa are not being driven by evidence, say Spanish and Mozambican reasearchers, after an autopsy study published this week in PLoS Medicine revealed that half of mothers died of infectious causes and just under one in seven died of HIV-related causes. Common obstetric complications accounted for just 38% of deaths during pregnancy, labour or after delivery.
Maternal death due to complications during labour or infection after delivery has been a fact of life throughout human history, but improvements in medical care have resulted in enormous reductions in maternal mortality since the 19th century in wealthy nations.
However, the lifetime risk of maternal death is one in six in Sierra Leone, compared with one in 30,000 in north-western Europe, and one of the stated Millenium Development Goals is the reduction of maternal mortality by three-quarters by 2015. Mozambique has the eighth highest rate of maternal death in the world.
The World Health Organization has stated that the main causes of maternal death are post-partum haemorrhage, puerperal sepsis, hypertensive disorders, obstructed labour, and abortion. It admitted that it was unable to quantify the effect of indirect conditions, such as infections, on maternal mortality.
Without better information on the causes of maternal death, there is a danger that health system investments designed to reduce maternal mortality will fail to have a significant effect. The lack of clarity about the causes of maternal death may also encourage assertions that particular diseases, such as HIV, are being over-funded in comparison with routine maternal health care.
In order to improve their understanding of causes of maternal death in Mozambique, researchers from the University of Barcelona and Maputo Central Hospital in Mozambique designed a prospective autopsy study in all mothers who died between October 2002 and December 2004.
One hundred and seventy-nine maternal deaths occurred among 21,135 live births during the study period, giving a maternal mortality ratio of 8.47 per 1000 live births.
The most common causes of death were haemorrhage (16.6%), HIV-related conditions (12.9%), pyogenic bronchopneumonia (12.2%), severe malaria (10.1%), puerperal septicaemia (8.7%), eclampsia (8.7%) and pyogenic meningitis (7.2%).
Overall, 48% of deaths were due to preventable infectious diseases: HIV-related conditions, pyogenic pneumonia, severe malaria and pyogenic meningitis. Thirty-eight per cent of deaths were due to obstetric complications such as haemorrhage.
HIV testing was carried out in 123 of 139 women; 52% were HIV-positive. Almost 13% of deaths were due to HIV-related conditions; in just over half these cases the cause was mycobacterial.
The authors note: ““A susbtantial reduction in maternal mortality would be achieved by increasing the uptake of HIV testing during pregnancy, antiretroviral treatment in HIV-positive pregnant women, and preventive measures in the general population.”
Malaria was also an important cause of death, despite the fact that Maputo, Mozambique’s capital, has a low malaria burden due to malaria control measures. The auhtors point out that Maputo, like other large cities in the developing world, is surrounded by areas where malaria is highly endemic, and an increase in maternal deaths due to malaria can be expected in large cities.
They also point out the high rate of death due to pyogenic pneumonia, a condition that is easily treated with antibiotics and an infrequent cause of death in adults with no other serious health condition.
The main limitation of the study is the restriction of sampling to women who died after referral to a tertiary level hospital in the capital of Mozambique. The authors admit that rates of haemorrhage might be higher in rural settings, due to the inability to refer cases to hospitals.
Menendez C et al. An autopsy study of maternal mortality in Mozabique: the contribution of infectious diseases. PLoS Medicine 5 (2): e44, 2008.