Malaria during pregnancy a risk factor for stillbirth

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Expectant mothers in the five counties that are hardest hit by the malaria outbreak are at risk of having stillbirths.

Authors of a new study published in the Lancet Global Health estimate that in Africa, between 132,000 and 221,000 stillbirths per year (between 12 to 20 per cent of all stillbirths) are as a result of malaria in pregnant women.

Researchers reviewed 59 studies and found that in nearly 20 studies the odds of stillbirth increased by 1.47 in pregnant women who were diagnosed with and treated for malaria. In over 30 studies, the odds of stillbirth after a malaria diagnosis and treatment increased by 1.81. Malaria in the placenta increased the odds of stillbirth by 1.95.

The risk of stillbirth was influenced by the intensity of malaria transmission. The risk of stillbirth was double in areas that are low-to-intermediate malaria endemic as compared to moderate-to-high malaria endemic areas.

Low levels of protective immunity in pregnant women result in more severe clinical manifestations of malaria, including higher densities of placental infections in settings with more sustained levels of transmission.

As infection becomes less common because of decreasing transmission, the clinical severity of those infections, including the risk of stillbirth, might increase.

A RISK FACTOR

Malaria is likely to remain a risk factor for stillbirth in the foreseeable future due to reductions in protective immunity thatmight shift the burden of malaria in pregnancy more widely across all gravidae rather than being concentrated in first and second pregnancies.

Therefore, even in areas where transmission has decreased considerably, protection of pregnant women from malaria will remain crucial

Globally, most stillbirths are preventable. An estimated 2·6 million third-trimester stillbirths occur annually, and over 90 per cent of these stillbirths result from modifiable medical conditions. Such disorders include chronic non-communicable diseases such as obesity, hypertension, and diabetes; obstetric conditions such as advanced maternal age and post-term pregnancies; and infections such as syphilis.

Stillbirths occur at the highest rates in southern Asia (25·5 per 1000 births) and sub-Saharan Africa (28·7 per 1000 births).

Malaria in pregnancy has devastating consequences for the developing foetus, resulting in preterm delivery and intrauterine-growth retardation, and is believed to be a major contributor to spontaneous abortions and stillbirths.

This is a hidden burden of malaria mortality, because stillbirths are not captured in standard estimates of infant and under 5 mortality.

Investment in strategies to enhance the uptake and effectiveness of malaria prevention during pregnancy can help increase perinatal survival rates and reduce stillbirths in malaria endemic areas.

 DISEASE ON DECLINE

Prevalence of malaria declined from 40 per cent in children aged 2 to 10 years between 1900 and 1929, to 24 per cent between 2010 and 2015.

The peak in the late 1900s has been attributed to excessive rainfall and the emergence of chloroquine resistance which was used to treat malaria.

Previous global initiatives have contributed to an unprecedented decline in infection since 2000, though reduction has not occurred uniformly throughout the continent, leaving large parts of West and Central Africa with high transmission rates.

According to the researchers one in four children still carry the malaria parasite and there are areas of the continent that haven’t changed much in the last three decades.

Therefore, if insecticide and drug resistance becomes established, or excessive rainfall hits Africa again, malaria will revert in large parts of Africa to the high levels we saw in the 1990s.

The researchers argue that there is need for new tools in the low-income and high malaria burden areas of Africa, where gains in malaria reduction have stalled.

The team identified several challenges facing malaria control, including emerging insecticide and drug resistance, and inadequate funding plans for replacing long-lasting insecticide-treated nets.

The African region carries disproportionately high levels of infection risk, with over 90 per cent of malaria cases and 92 per cent of malaria deaths according to the 2016 WHO World Malaria Report. This requires quick diagnosis and treatment to avert deaths.