Two simple blood tests could help to predict which pregnant women with high blood pressure are at risk of serious complications, including seizures, stillbirth and newborn death, a new study conducted in Sierra Leone has found.

The study is the first to show how such tests, which are simple to perform and give results within 30 minutes, could help to improve safety for mothers and babies in pregnancies affected by high blood pressure in settings where maternity and neonatal care resources are limited.

Led by King’s College London in collaboration with the Princess Christian Maternity Hospital in Sierra Leone and published in the journal Hypertension, the study included 488 pregnant women admitted to hospital with suspected preeclampsia—a pregnancy condition that causes high blood pressure and protein in the urine, and can lead to life-threatening complications for mother and baby.

Women with preeclampsia have low blood levels of placental growth factor (PlGF)—a protein that is important for the healthy development of the placenta during pregnancy.

The team found that using either of two blood tests (called RONIA and Lepzi Quanti), designed to measure the levels of PlGF at “point of care” (on admission to hospital), could help to identify women at risk of developing serious complications related to preeclampsia. In women who were less than 34 weeks pregnant, the tests correctly identified 95%–100% of women at risk of maternal death or seizures, and 100% of babies at risk of stillbirth.

“The tests were very good at ruling out serious problems when results were normal, meaning these women were unlikely to have life-threatening complications. Abnormal test results identified women at higher risk who may need closer monitoring or earlier delivery of the baby,” says Dr. Katy Kuhrt, Clinical Research Fellow and Registrar in Obstetrics and Gynecology at the Department of Women & Children’s Health at King’s and lead author of the study.

“Our study shows that simple, bedside blood tests could help doctors decide which women need urgent care, improving safety for mothers and babies in pregnancies affected by high blood pressure,” says Dr. Kuhrt.

Preeclampsia affects 2%–8% of pregnancies worldwide and each year results in about 46,000 maternal deaths and 500,000 fetal or newborn deaths. Those in lower- and middle-income countries (LMICs) are disproportionately affected due to limited access to diagnostic and monitoring equipment and neonatal intensive care.

While PlGF testing improves management and outcomes of preeclampsia, existing methods used in the clinic require blood samples to be sent to the laboratory for processing—making them difficult to implement in LMICs. Importantly, the two new tests used in this study can be performed at the hospital bedside using only a small drop of blood, acquired using a finger prick. Results are available in 15–30 minutes.

“Serious outcomes such as stillbirths can be easily avoided if we just know who is at risk. This test accurately provides this knowledge for the first time, and is suitable in settings where stillbirths are common. We are very excited about this test really being able to save lives,” says Professor Andrew Shennan, Professor of Obstetrics at King’s and senior author of the study.

Building on this work, the NIHR Global Health Research Group PAPAGAIO (Preterm preeclampsiA: PlAcental Growth factor testing for reduction of Adverse Outcomes), led by Professor Shennan, is working to introduce point-of-care PlGF testing into clinical care of women with suspected preeclampsia in Brazil, India, Sierra Leone and Zambia to understand the impact of testing on clinical management and outcomes for mothers and their babies.