The rapid diagnosis of pre-eclampsia, identification of placental dysfunction and likelihood of pre-term delivery is essential to ensure positive outcomes in pregnancy. A test deployed at the point of care or in rapid testing facilities for Placental Growth Factor (PlGF) can support clinical decisions in the detection and management of pre-eclampsia.
Abnormally low levels of maternal circulating PlGF at the first presentation are suggestive of the presence of placental dysfunction and are predictive of the development of pre-eclampsia and its complications.
Pre-eclampsia
Pre-eclampsia is a potentially life-threatening condition that affects some pregnant women either during or shortly after their pregnancy. The symptoms tend to present after 20 weeks gestation with early signs of pre-eclampsia including high blood pressure (hypertension) and proteinuria (protein in the urine). These tests are generally poor at predicting pre-eclampsia with only 38% of pregnant women of the total women investigated for pre-eclampsia having both hypertension and proteinuria 1,2.
The symptoms may not be easily detectable by the patient but will normally be picked up at routine ante-natal appointments whilst routine observations are being recorded. There may be other symptoms that present in a minority of cases such as blurred vision and headaches. Others may experience vomiting, pain in the thorax or swelling of the feet, hands or face.
A number of other factors can increase the chance of pre-eclampsia during pregnancy which can be found here https://www.nhs.uk/conditions/pre-eclampsia/. Most cases are mild but the earlier pre-eclampsia is detected the better the outcome for mother and baby. In rare cases the conditions can cause fitting which can become life-threatening for the mother and baby especially if gone undiagnosed or treated.
The condition has a high clinical suspicion and a low threshold for admitting pregnant women for management and potentially pre-term delivery of the baby.
A Significant Problem
According to NHS England, 65,000 pregnant women a year are admitted to hospital with symptoms of pre-eclampsia leading to an average of three days hospital stay to monitor the symptoms. The only way to resolve pre-eclampsia is to safely deliver the baby (potentially pre-term), but in some cases the symptoms need to be managed until a safe delivery can be achieved.
Pre-eclampsia is a complex clinical syndrome, affecting 3% of all pregnancies3. The cause of pre-eclampsia is thought to originate in the placenta. Placentation, the formation and growth of the placenta, occurs after implantation of the embryo into the uterine wall. This occurs between 6 and 18 weeks of pregnancy and involves a change in blood flow to the placenta to support the placental growth and development of the foetus. In pre-term eclampsia, this re-modelling of the spiral arteries partially fails which can lead to oxidative stress or placental injury, ultimately promoting foetal growth restriction and the symptoms described above.
The introduction of a simple test at the point of care for placental growth factor (PlGF) greatly improves the diagnosis of pre-eclampsia and risk stratification for pre-term delivery.
Quidel Triage MeterPro PlGF Test
‘The PARROT trial demonstrated that PlGF, measured on the Quidel Triage MeterPro, led to a faster diagnosis of pre-eclampsia, less maternal morbidity and better resource targeting with no evidence of a difference in perinatal adverse outcome or gestational age of delivery.’ (Quidel PlGF Brochure)
Furthermore, the use of PlGF could lead to cost savings within the maternity health sector through better and more rapid diagnosis of the condition, improved use outpatient clinic time, and reduction in the use of specialist ultrasound investigations where they are unwarranted.
“At last, with the Quidel Triage PlGF Test, we have a simple and reliable tool guiding clinicians to target women who will benefit from these interventions, whilst limiting unnecessary healthcare expenditures incurred by managing women at low risk for needing preterm delivery.”
Professor Andrew Shennan, Kings College London
Key Benefits
Measuring PlGF in expectant mothers suspected of having pre-eclampsia:
- Provides pathologically relevant information for use alongside other investigations
- Accurately risk stratifies women in their first presentation with suspected pre-eclampsia
- Helps reach a faster diagnosis and better resource targeting
- Helps appropriately adjust clinical surveillance and, where indicated, plan for preterm delivery
- May lead to less maternal morbidity without increasing perinatal adverse outcomes
Key Features of the Quidel Point of Care Test for PlGF
- Highly specific for PlGF isoform-1
- Results available in approximately 15 minutes
- Measurable range: 12-3,000 pg/mL
- Requires 250 μL of EDTA plasma from maternal blood
- Runs on the Quidel Triage MeterPro
- Can be used in the laboratory and/or point of care setting
The diagnostic accuracy of the Quidel PlGF test compared to other markers can be viewed here:
https://poctinnovators.com/wp-content/uploads/2021/11/Triage-PLGF-Brochure.pdf
Wide Adoption of PlGF Testing
From https://www.england.nhs.uk/2021/08/life-saving-world-first-nhs-test-for-pregnant-women/ published August 2021
‘The new testing (PlGF) is being rolled out as part of the NHS Long Term Plan’s ambitions to invest in more world-class treatments and cutting-edge technologies.
Three-quarters of maternity units are using the test which has helped tens of thousands of women already and will be available across all of England within the next two years.
NHS clinical director for maternity and women’s health Matthew Jolly said: “Pre-eclampsia is a life-threatening condition for both mum and baby if left untreated and this is why the NHS takes every precaution possible when soon-to-be mums have some of the early signs like high blood pressure.
“This new way of testing means we can rule out the condition in a much quicker and easier way – it removes the stress that comes with the uncertainty around not having a diagnosis and will reassure thousands of pregnant women every year.”
NHS director of innovation, research and life sciences Matt Whitty said: “This test is quick and easy and can rule out a condition that has for a long time been the of cause such stress to tens of thousands of pregnant women every year, whether they have pre-eclampsia or not.
“This latest innovation will benefit thousands of patients who have until now been put through extensive testing and possible hospital stays as the NHS continues to deliver on ambitious Long Term Plan commitments to provide patients with the most up to date tech, as quickly as possible.”
References
- Douglas KA., & Redman, C. Eclampsia in the United Kingdom. BMJ 1994; 309:1395-1400.
- Knight M. (2007) Knight M, on behalf of UKOSS. Eclampsia in the United Kingdom 2005. BJOG;114:1072-8
- Duley L. The global impact of pre-eclampsia and eclampsia. Semin Perinatol 2009; 33:130–37
Sources
https://www.nhs.uk/conditions/pre-eclampsia/
https://www.england.nhs.uk/2021/08/life-saving-world-first-nhs-test-for-pregnant-women/
https://poctinnovators.com/wp-content/uploads/2021/11/Triage-PLGF-Brochure.pdf
Visit https://poctinnovators.com/product/quidel-triage-meterpro/ for more information about the Quidel Triage MeterPro and its versatility.