PARROT: using placental growth factor to tell if women are at high risk of pre-eclampsia

Professor Andrew Shennan, Professor Lucy Chappell, Dr Annette Briley, Professor Lucy Chappell, Professor Lucilla Poston, Professor Marcos Bastos Dias, Professor Jim Roberts, Chris Redman, Professor Peter Von Dadelszen

Scientists are looking at whether a simple test for a protein can identify women at risk of severe complications from pre-eclampsia.

Pre-eclampsia is a condition that only happens during pregnancy. Mothers who develop it can suffer from high blood pressure, blood clotting, and problems with their liver and kidneys.  The cause isn’t fully understood, but we think that it is related to the placenta not attaching properly to the wall of the womb. The placenta is incredibly important for the growing baby: it supplies it with all of the nutrients and oxygen it needs to survive in the womb. Problems with the placenta can stop the baby from growing as much as it should (fetal growth restriction), and in some cases can lead to stillbirth.

Pre-eclampsia is diagnosed through testing a woman’s blood pressure, as well as the amount of protein in her urine. If a woman is diagnosed, she may need to be admitted to hospital to have her blood pressure treated, and to be monitored closely whilst planning for safe delivery of the baby. Some women become unwell very quickly and need to have their baby delivered straight away. Others will need long stays in hospital so that they can be observed.

At the moment, we can’t always know which women are at risk of severe complications and need early delivery for the safety of themselves and the baby.

The PARROT trial is looking at levels of a protein made by the placenta called placenta growth factor (PlGF), which can be detected by a simple blood test. Previous studies have shown that women with very low levels of PlGF are more likely to develop severe pre-eclampsia, or have a stillborn baby. Women with normal PlGF levels are at low risk, and can return to normal antenatal care. This means that care is focused on the women that really need it, while those that don’t avoid long stays in hospital. This treatment would also save costs for the NHS. 

We have now reached our recruitment target of 1000 women and we anticipate that our research will be complete by March 2019.

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Read more: the PREPARE study

Working with the Gates foundation, we are supporting a study in Brazil to prevent premature birth by improving the care of women with pre-eclampsia. The PREPARE study will take place in 7 different centres across Brazil, and will include measurements of PlGF in the same way as the PARROT trial. As well as measuring PlGF, the study will introduce more accurate measurement of blood pressure using our MicroLife CRADLE device. It will also help put into effect WHO recommendations for treating women at high risk of pre-eclampsia. These include giving women at risk preventive treatments such as calcium supplements and aspirin. The project will help doctors in Brazil to decide which women need to deliver their babies straight away, and which are at lower risk.

This study started in December 2016 and so far, 350 women have been recruited to take part.

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This study takes place in a Tommy's centre and is funded by Tommy's and the National Institute for Health Research's Research for Patient Benefit stream

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