Malaria during pregnancy: New study assesses risks during first trimester
The largest ever study to assess the effects of malaria and its treatment in the first trimester of pregnancy has shown that the disease significantly increases the risk of miscarriage, but that treating with antimalarial drugs is relatively safe and reduces this risk.
In the study, carried out at the Shoklo Malaria Research Unit (SMRU), in Thailand and funded by the Wellcome Trust, researchers examined medical records of women attending the unit's antenatal clinic over the 25 years since it was founded.
Malaria kills around one million people each year, mainly children and pregnant women. Malaria in pregnancy is a major cause of maternal mortality, and low birth weight which predisposes to neonatal mortality. The disease is caused by infection with the malaria parasite, with two major species Plasmodium falciparum and Plasmodium vivax commonly infecting pregnant women in the South East Asia region The parasites are transmitted into the blood stream through the bite of infected mosquitos. They proceed to enter the liver where they multiply before leaving and infecting red blood cells. P. vivax is able to re-emerge from the liver stage which cannot be treated in pregnancy.
The most effective drug for treating malaria is artemisinin, which is usually given as part of a combination therapy, a cocktail of drugs aimed at treating the disease whilst reducing the risk of the emergence of parasites resistant to one particular drug. Artemisinin combination therapies (ACT) are recommended by the World Health Organization for the treatment of malaria except in the first trimester. This is because animal studies have indicated that the drugs can be toxic to embryos.
Despite the risks to pregnant women, there is very little published evidence on the effects of malaria and antimalarial drug exposure during the first trimester of pregnancy. This is in part because antenatal clinic services are often unavailable in the rural tropics and if they are, women rarely attend the clinics before their second trimester. Also, pregnant women are usually excluded from clinical trials of new drugs because of the risks of adverse effects; no randomised controlled trial has ever been carried out on how best to treat malaria in the first trimester.
In a study published today in the journal Lancet Infectious Diseases, researchers at the SMRU, part of the Wellcome Trust-Mahidol University-Oxford University Tropical Medicine Research Programme, examined the records of all women attending antenatal clinics at the unit. Of these, 16,668 had no malaria during pregnancy, whilst 945 had only a single episode during their first trimester and no episodes later in pregnancy.
Around one in five pregnancies resulted in miscarriage when malaria was not a factor. Symptomatic malaria increased the risk of miscarriage to one in two pregnancies; for asymptomatic malaria, the risk of miscarriage was one in three pregnancies. In women with malaria, more severe disease, higher levels of parasites in the blood and infection at an earlier stage of pregnancy increased the risk of miscarriage further. The risks associated with miscarriage were similar for P. falciparum and P. vivax infections.
P. falciparum infections were treated with quinine or artesunate, or inadvertently with ACT, and P. vivax with chloroquine. Of the women treated (irrespective of symptoms), 26% miscarried following chloroquine, 27% following quinine and 31% following artesunate. After inadvertent treatment with an ACT the miscarriage rate was 24%, comparable to the rate associated with other treatments.
"Malaria is a potentially deadly disease and is particularly dangerous during pregnancy, both to the health of the mother and to the health of her unborn child," explains Dr Rose McGready from the Shoklo Malaria Research Unit. "Understanding the risks is essential for weighing up the treatment options. Our work has highlighted the particular risk factors with malaria infection during pregnancy. Particularly worrying is the risk of miscarriage even when the disease is asymptomatic. However, whilst the dangers of miscarriage are considerable, our study offers some good news, that the most common drugs reduce this risk significantly."
Combating infectious diseases is one the strategic priorities of the Wellcome Trust. Much of this work is carried out at a local level in regions where disease is endemic. This includes several major overseas programmes, including the Wellcome Trust-Mahidol University-Oxford University Tropical Medicine Research Programme.
Dr Jimmy Whitworth, Head of International Activities at the Wellcome Trust, says: "This is a very important observational study on the risks of treating malaria in women in early pregnancy, a key high-risk group for this infection. These results, which come from the research group that has done the majority of studies of malaria in pregnancy anywhere in the world, show that antimalarial treatment with standard first-line drugs reduces the risk of miscarriage in the first trimester. These findings are likely to change practice guidelines worldwide and to save the lives of many women and unborn children."
Journal reference: Lancet Infectious Diseases
Provided by Wellcome Trust
- Better treatments for malaria in pregnancy are needed Jun 17, 2008 | not rated yet | 0
- Most effective malaria drug regimens highlighted in study Sep 09, 2010 | not rated yet | 0
- Profiling malaria-causing parasites Feb 07, 2011 | not rated yet | 0
- New study finds 125 million pregnancies globally at risk from malaria every year Jan 26, 2010 | not rated yet | 0
- Studies identify more effective treatment for malaria control during pregnancy in Africa Jun 20, 2007 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Assumptions of Griffith's fracture theory
1 hour ago Any experts on Griffith's fracture theory? I am studying the subject and I am having hard time finding out if the theory is valid for all possible...
Current leading voltage or vice versa concept
2 hours ago Hello, I was wondering if there is a conceptual explanation for when current leads voltage or vice versa for capacitors or inductors with AC...
Angular Frequency of AC voltage
5 hours ago Hello, I am wondering, what is the physical interpretation of the angular frequency of AC voltage? I don't see the physicality of what the angle...
Modeling Rigid Body - Unsure about Euler angles and angular velocity
6 hours ago I'm modeling a single 3D rigid body in preparation for some more complicated modeling in order to gain a better understanding of Euler angles, the...
Function for a bullet's path
7 hours ago I've been mulling this over all weekend, and I've decided to get some help on this. The problem is writing a function to describe a bullet's path....
Elementary questions relating to Newton's laws of motion
8 hours ago i) If a wall breaks when it gets hit by a cannonball, did the wall exert an equal and opposite force on the cannonball? ii) Would the force...
- More from Physics Forums - Classical Physics
More news stories
Nearly three out of four pregnant women experience constipation, diarrhea or other bowel disorders during their pregnancies, a Loyola University Medical Center study has found.
Obstetrics & gynaecology 11 hours ago | not rated yet | 0
New research indicates that women's reproductive function may be tied to their immune status. Previous studies have found this association in human males, but not females.
Obstetrics & gynaecology May 17, 2013 | not rated yet | 0 |
Elsevier today announced the publication of a recent study in Reproductive BioMedicine Online on 5-day old human blastocysts showing that those with an abnormal chromosomal composition can be identified by the rate at whic ...
Obstetrics & gynaecology May 16, 2013 | not rated yet | 0
While global attention has for decades been focused on reducing maternal mortality, population-based data on other causes of death among women of reproductive age has been virtually non-existent. A study conducted by researchers ...
Obstetrics & gynaecology May 14, 2013 | not rated yet | 0
Doctors have terminated the pregnancy of a 23-year-old Turkish woman who was the first ever to receive a uterus transplant from a dead donor, a hospital in southern Turkey said on Tuesday.
Obstetrics & gynaecology May 14, 2013 | not rated yet | 0
Early-life exposure to traffic-related air pollution was significantly associated with higher hyperactivity scores at age 7, according to new research from the University of Cincinnati (UC) and Cincinnati Children's Hospital ...
3 hours ago | not rated yet | 0 |
(Medical Xpress)—A research team, led by Jeremy Barr, a biology post-doctoral fellow, unveils a new immune system that protects humans and animals from infection.
8 hours ago | 4.6 / 5 (12) | 4 |
New research suggests that a compound abundant in the Mediterranean diet takes away cancer cells' "superpower" to escape death. By altering a very specific step in gene regulation, this compound essentially re-educates cancer ...
11 hours ago | 4.8 / 5 (11) | 2 |
Salamanders' immune systems are key to their remarkable ability to regrow limbs, and could also underpin their ability to regenerate spinal cords, brain tissue and even parts of their hearts, scientists have ...
12 hours ago | 4.8 / 5 (6) | 2 |
Researchers have pinpointed a catalytic trigger for the onset of Alzheimer's disease – when the fundamental structure of a protein molecule changes to cause a chain reaction that leads to the death of neurons ...
12 hours ago | 5 / 5 (3) | 0 |
Bacteria resistant to the antibiotic colistin are also commonly resistant to antimicrobial substances made by the human body, according to a study in mBio, the online open-access journal of the American Society for Microb ...
3 hours ago | 5 / 5 (1) | 0