9th February 2016, Mae Sot (Thailand) – Artemisinins, the most effective antimalarials available, should be endorsed in the first trimester of pregnancy to ensure optimal treatment of falciparum malaria in pregnant women, reports a paper published today in The Lancet Infectious Diseases.
Noting quinine’s low efficacy and the wide availability of effective artemisinin combination treatments, the study’s authors urge health authorities to revise their current treatment protocols for malaria.
“Because of the risk of miscarriage or congenital abnormalities, doctors are justifiably worried about drugs in the first trimester of pregnancy. We found no evidence that treatment of malaria with artemisinins in the first trimester increased the risk of miscarriage compared with quinine treatment,” said Ms Kerryn Moore, the study’s author.
Malaria infects 125 million pregnant women annually, increasing the risk of maternal and infant death and also impairing the development of children born to mothers infected during pregnancy.
Although malaria increases the risk of miscarriage, the study – which assessed all medical records of 55,636 women who visited Shoklo Malaria Research Unit (SMRU) antenatal clinics since 1994 – found no evidence that treatment with an artemisinin derivative was associated with an increased risk of miscarriage or congenital malformations. The study includes the largest number of confirmed first-trimester malaria treatments with artemisinins or quinine.
A unit of the Bangkok-based Mahidol Oxford Tropical Medicine Research Unit (MORU), SMRU is based in the refugee camps and migrant communities along the Thai-Myanmar border.
“The study adds to the body of evidence that artemisinins do not cause adverse effects in pregnancy,” said Oxford Prof Nick White, South-East Asia chairman of the Mahidol Oxford Tropical Medicine Research Unit (MORU). “Its findings should help international authorities and national health programmes reconsider their treatment recommendations for women in early pregnancy and reassure women who receive artemisinins that the drugs are safe and unlikely to harm their unborn child.”
Women who get malaria in their first trimester of pregnancy are more likely to miscarry, but under current guidelines from the World Health Organisation (WHO) artemisinin treatment is not recommended, unless their life is at risk. For a decade, artemisinins have been the first-line treatment for falciparum malaria in the general population, but because animal studies have found they are associated with miscarriage and congenital malformation in early pregnancy, their safety in the first trimester of pregnancy in humans has remained uncertain. Therefore, the recommended treatment for malaria in first trimester is quinine – an antiquated, less effective, and poorly tolerated antimalarial.
The study estimated that malaria in first trimester increased the risk of miscarriage by 60%. Recurrent malaria in first trimester, which can be the result of ineffective treatment, increased the risk of miscarriage more than three-fold. The risk of miscarriage following treatment with artemisinins was not higher, and possibly even lower, than after treatment of malaria with quinine.
“Pregnant women are at high risk of malaria and miscarriage in first trimester, so effective treatment is imperative,” said Oxford Prof Rose McGready, Deputy Director of SMRU. “Artemisinin treatments are widely available, have excellent tolerability, and are very effective. Others have reported that artemisinin treatment in first trimester is also very common in practice, despite current recommendations.”
Led by researchers at the Shoklo Malaria Research Unit (Thailand), The University of Melbourne (Australia), and the Burnet Institute (Australia), among others, the study was funded by the Wellcome Trust (UK) and the Bill & Melinda Gates Foundation (US).