Sparks, the children’s medical research charity, has been funding a project at St Mary’s Hospital, Manchester, which aims to develop a much more accurate screening test for pre-eclampsia.
Pre-eclampsia is a common condition affecting 2 – 8 in 100 women; it is unique to pregnancy and can occur at any time from 20 weeks’ gestation onwards, including immediately post birth. It is particularly prevalent amongst first-time mothers (nulliparous women). Two per cent of women with pre-eclampsia will go on to develop eclampsia. Worldwide, every year, more than four million women will develop pre-eclampsia with around 100,000 women experiencing eclamptic convulsions. Ninety per cent of these cases occur in developing countries (RCOG 2012).
The majority of cases are mild and present at the very end of the pregnancy and do not compromise the health of the mother or her baby. Where women present with the more serious form of the condition (1:200 women), they can also develop reversible organ damage and blood clotting disturbances. Left untreated, pre-eclampsia can lead to serious complications, morbidity and mortality (Robson 2002, Lewis 2004).
The signs and symptoms of pre-eclampsia include high blood pressure (hypertension), fluid retention (oedema) and protein in the urine (proteinuria). In the unborn baby, pre-eclampsia can cause growth problems with babies showing intrauterine growth restriction (IUGR).
Although the exact cause is not known, it is thought that pre-eclampsia occurs when there is a problem with the placenta (the organ that links the baby’s blood supply to the mother’s). Pregnant women with pre-eclampsia may not realise they have it until the condition is diagnosed, usually during routine antenatal appointments. Mild pre-eclampsia can be monitored with blood pressure and urine tests at regular antenatal appointments and symptoms usually disappear soon after the baby’s birth. However, severe cases of pre-eclampsia need much closer observation and serial monitoring, which tends to be undertaken in hospital (Tuffnell et al 2006).
Each year, hundreds of babies die in the UK following complications from pre-eclampsia, often as a result of premature birth. It is also responsible for the deaths of around six women a year in the UK (NHS Choices 2011). The primary treatment is the early delivery of the baby; however being born prematurely carries its own risks. Whether this can be done safely will very much depend on the gestation of the pregnancy/fetal maturity.
This Sparks funded project aims to develop a test (an assay) that combines new and previously recognised circulating ‘biomarkers’ for pre-eclampsia found in the bloodstream of expectant mothers.
Using markers that singularly have poor predictive capabilities but which in combination could provide a robust early screening test for this significant condition, a team led by Dr Ian Crocker, Senior Scientist at St Mary’s Hospital Manchester have been validating the test against blood samples collected from women with underlying health complications which predispose them to pre-eclampsia.
If the research project at St Mary’s Hospital is successful, it will enhance care for women during pregnancy and their unborn babies. Catherine Chmiel, a Research Midwife working on the project, explains why she is so passionate about this work.
“Through my work as a midwife, I often come into close contact with pregnant women and babies affected by pre-eclampsia and this encouraged me to get involved in research that could improve the care for women on a larger scale. I didn’t want to just make a difference to women in my care – I wanted that to extend to pregnant women and babies around the world.
Hopefully this project will result in less women and babies dying from the effects of pre-eclampsia – at present it’s one of the most common causes of maternal death in the UK. I also hope that we’ll reduce the number of complications associated with pre-eclampsia, such as pre-term delivery; small birth-weight babies; and long-term health complications, like raised blood pressure and diabetes. All of these can have serious long term implications for both mother and baby.
The main goal of the project is to produce a screening test that will, hopefully, one day, be accessible to every pregnant woman. The test will classify their risk of pre-eclampsia by grouping them into a high or low-risk category. The idea would be to improve antenatal care for those at high risk of pre-eclampsia, by means of a specialist antenatal clinic run by doctors and midwives who are experts in the condition. Hopefully prompt intervention and treatment will lead to better results for both mother and baby.
To conduct this kind of research over a long period of time, you need to be focused on improving the lives of many pregnant women and babies in the future. For me personally, seeing first-hand the effects of pre-eclampsia as a clinical midwife is enough to keep me dedicated to making this project a success.
This is about the women and the babies. It is because of them that I wanted to be heavily involved in this research. I became a midwife to make a difference and, by running this project from the front line in the antenatal clinics at St Mary’s Hospital, I feel that I am working towards fulfilling that goal.”
Lewis G ed (2004). Why mothers die 2000-2002: the sixth report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. London: RCOG Press. 338 pages.
NHS Choices (2011). Pre-eclampsia http://www.nhs.uk/conditions/pre-eclampsia/pages/introduction.aspx
Robson S (2002). Pre-eclampsia and eclampsia. In: MacLean AB Neilson JP eds. Maternal morbidity and mortality. London. RCOG Press. 201-213.
Tuffnell DJ, Shennan AH, Waugh JJS et al (2006). The management of severe pre-eclampsia/eclampsia. London: Royal College of Obstetricians and Gynaecologists. 11 pages.