Rose McGready: Malaria in pregnancy

This is a podcast from the Nuffield Department of Medicine. Today we talk to Professor Rose McGready about her research on malaria in pregnancy.

Q: Why is malaria in pregnancy particularly harmful?

Rose McGready: On the Thai-Myanmar border where I work, the most obvious harm we see is when a pregnant woman dies from severe malaria. As a clinician, sending home the husband with the two children without the mother is very harrowing, and made worse because these deaths are preventable. We see tens of thousand of these deaths every year.

Uncomplicated malaria is also harmful but it is much more sinister. The mother might not have any symptoms at all of malaria, but her foetus is on a pathway to be born with a low birth weight and premature. Then it has a higher risk of mortality in the first year of life, it cannot reach its full growth potential which means it will be short in stature and not do as well at school or at job attainment. When a baby born too small reaches adulthood, they suffer diseases like diabetes and hypertension. So malaria sets up this really negative health cycle, which is not just destructive to the individual but to the countries endemic for malaria.

Q: How do you treat malaria in pregnancy?

RMG: I would really rather prevent malaria in pregnancy, failing that we treat. Treatment is fairly similar to uncomplicated malaria in non-pregnant patients, except for the first trimester, where we use quinine rather than an artemisinin derivative. Pregnancy already makes you susceptible to anaemia, so we are very vigilant at looking for and treating anaemia.

Severe malaria in pregnancy has got a very high mortality rate. We would like to take care of these women in intensive care, but in most rural and resource-poor settings, these are very hard to access. For example, if I had ten women with severe malaria in intensive care in good facilities and gave them my best drug - intravenous artesunate - still two of them will die, they won't go home. Our intention is to save the life of the mother, but a lot of those women will also lose their baby.

Q: What is your approach to malaria in pregnancy?

RMG: Where we are on the Thai-Myanmar border, the drugs that we would normally give a woman to prevent malaria have all been lost to resistance, so we cannot prevent with drugs. We also know that two thirds of our deaths occur before delivery, so we have to offer early detection and treatment. Each time we see the pregnant women we do a finger prick blood smear, we check for malaria and we treat very early. There is a 50% chance that if she had malaria, the parasites will come back, so we need to follow up right up to delivery. For delivery, we really encourage all women to birth with trained and skilled birth attendants, because they have the skills and the resources to prevent the unexpected events during childbirth.

Q: What are the most important lines of research that have emerged in the last 5-10 years?

RMG: I think artemisinins, that we now know can be used safely in pregnancies, is number one and have saved many lives. In 2001 we introduced ultrasounds in our setting and that was a big challenge. The clinics are made of bamboo, we get surges in the electric supply, certain insects favour the warm and dry insides of the machine. Once we got over that, we could document what happens in early pregnancy. Malaria is associated with miscarriage. More of a problem, when we talk about those babies who are born too small - that is actually that’s happening very early in pregnancy, which brings into question how we can control malaria.

We have also looked at antibody responses throughout the length of pregnancy. It is quite hard to follow a woman for nine months, so this work is very importantly for vaccine studies. We have continued to work on vivax malaria; in fact 90% of our vivax infection is emerging from the liver. Our main problem is that the only drug we have for the liver stage, we can’t use it in pregnant women, which makes things difficult.

Q: Why does your line of research matter and why should we fund it?

RMG: I think if we can have a pregnancy free from malaria parasites - this is the most common parasitic infection of humans - then we will decrease infant and maternal mortality and morbidity significantly. If we can get that early in utero environment healthy, then this child has a chance at a productive life. That’s just one individual, but we are talking about malaria endemic countries and it can have a huge financial impact.

Q: How does your work fit into translational medicine within the department?

RMG: We documented artesunate use in pregnancies since 1992, slowly and carefully, every time we had to give that treatment. This has formed the backbone of evidence for the World Health Organisation to change their guidelines for pregnant women. The new findings on the early pregnancy effects that we have worked out with ultrasound, these are more challenging because our current policy is to treat pregnant women from the second trimester with antimalarials, but the early work says that is too late. So we need to rethink how we work. We could take a lesson from the West: then a woman has a disease we ask her to come early, to see her GP and we optimise her health before conception. If we could do that in resource-limited settings, we can take on a lot - we can look at anaemia, malaria, worms and sexually transmitted infections, and really optimise health before conception.

This interview was recorded in November 2015.