Addenbrooke’s and University of Cambridge to lead first-of-its-kind UK study on pre-eclampsia and placental complications in pregnancy

Addenbrooke’s Hospital will lead a study involving up to 3,500 first-time mums to understand why some develop pre-eclampsia and placental complications during pregnancy and whether it affects their long-term health.

Funded by Wellcome, the POPPY study (Preconception to pOst-partum study of cardiometabolic health in Primigravid PregnancY) will be the first large-scale study of its kind in the UK.

Women will be monitored before, during and after their first pregnancy to see what factors might be influencing the health of their placenta and their long-term cardiovascular risk.

Women who experience placental complications are twice as likely to develop heart disease and diabetes later in life, compared with those who have a healthy pregnancy.

The hope is that by understanding the risks, the health of women who develop placental complications can also be improved over their lifetime.

Placental complications affect around 1 in 10 pregnancies and include:
- pre-eclampsia - high blood pressure involving the kidney, liver or brain;
- gestational hypertension - high blood pressure during pregnancy; and
- fetal growth restriction - where the baby is small.

Such conditions can lead to serious complications for both mother and baby if not monitored or treated.

High blood pressure, also known as hypertension, diabetes, autoimmune conditions, age and obesity before pregnancy are some of the factors likely to increase the risk of pre-eclampsia and placental dysfunction.

It is unclear exactly why, however, and whether there are other causes.

It is also not clear whether placental complications cause heart disease and diabetes directly, or whether these conditions occur in women who already have some underlying or unknown health issues before pregnancy.

Currently, women thought to be at high risk of developing pre-eclampsia are advised to take a 75-150mg daily dose of aspirin from the twelfth week of pregnancy until birth to reduce the risk of developing this condition.

If a woman develops pre-eclampsia, the only way to cure it is to deliver the baby, normally at around 37 to 38 weeks of pregnancy, although it can be earlier in more severe cases.

Led by a team from Cambridge University Hospitals NHS Foundation Trust (CUH) and the University of Cambridge, the study is also being carried out in Glasgow and up to four other research centres in London.

Dr Bernadette Jenner, a medical registrar in obstetric medicine and clinical pharmacology at CUH, will leadi the POPPY study in Cambridge.

She said: “This study is going to be monitoring thousands of women from before they become pregnant for the first time and will track them through to birth and beyond to try and discover why some develop placental conditions and others don’t. We also hope to find out whether or not these conditions trigger longer-term health issues such as heart disease and diabetes.

“We have a significant lack of understanding when it comes to placental conditions, especially when you consider how common they are, and the serious impact they can have on women and babies, which at times is life-threatening. To prevent pre-eclampsia and other placental conditions we need to know what really causes them and why. We have some big gaps in our knowledge and this study hopes to find answers.”

Prof Ian Wilkinson, who is leading the POPPY study, is a clinical pharmacologist and professor of therapeutics at the University of Cambridge.

He said: “The POPPY study is a world first and will help us to better understand why common complications of pregnancy adversely affect women’s long-term cardiovascular health. This is the key to reducing this risk and may also allow us to prevent pregnancy complications before they occur.

“Unfortunately, many women who suffer from pre-eclampsia, or one of the other placental complications, are not aware of the potential long-term risks, and very few of them are actively followed up after birth - despite recommendations by NICE.

“Therefore, whilst we await the findings of the POPPY study, it is important that women who have experienced one of these complications are seen by a medical professional in the months after delivery to ensure that their blood pressure and other cardiovascular risk factors are checked and treated if necessary.”

The POPPY study is now open at Addenbrooke’s in Cambridge, with two more study sites due to open soon at Glasgow Royal Infirmary NHS and Imperial College Healthcare NHS Trust, with further locations in London to start in the coming months.

Participants must be planning their first pregnancy and live in Cambridge, Glasgow or London. Participation will involve monitoring alongside regular pregnancy checks and tests.