Placental growth factor (PlGF)-based testing to help diagnose suspected preterm pre-eclampsia

Recommendations for NHSScotland

1. The following placental growth factor (PlGF)-based tests, used with standard clinical      assessment, are recommended as an option to help clinicians rule in or rule out                preterm (between 20 weeks and 36 weeks and 6 days of pregnancy) pre-eclampsia:

• DELFIA® Xpress PlGF 1‑2‑3
• DELFIA® Xpress sFlt‑1/PlGF 1‑2‑3 ratio
• Elecsys® immunoassay sFlt‑1/PlGF ratio
• Triage® PlGF Test                                                                                                                                                                                                                                                                                                        Not all manufacturers indicate their tests are suitable for use across the 20 weeks to 36 weeks and 6 days of pregnancy range. The tests should be used according to their indications for use.​

2.  Using PlGF-based testing may particularly benefit groups of people who have a               higher risk of developing pre-eclampsia and having severe adverse pregnancy                 outcomes, such as people from African, Caribbean and Asian family backgrounds, or       people from more deprived areas.

3.  A positive PlGF-based test used alongside standard clinical assessment can help             clinicians make a diagnosis of pre-eclampsia. The PlGF-based test does not indicate       the severity of the condition. PlGF-based test results should not be used to make             decisions about timing of birth in people with preterm pre-eclampsia. The NICE               guideline on hypertension in pregnancy has recommendations on timing of birth.

4. The PIGF-based test should be used once per episode of  suspected preterm pre-          clampsia. Further research is recommended on repeat testing. this should include:

• exploring the different scenarios in which repeat testing may be indicated
• the appropriate intervals between PIGF-based tests, and
• the diagnostic accuracy of repeat PIGF-based testing

5. BRAHMS sFlt‑1 Kryptor/BRAHMS PlGF plus Kryptor PE ratio is not recommended for      routine use in the NHS. Further research is needed to show the accuracy of this test        when using specified thresholds.

6. Further research is recommended into how the test will be used in people who are          pregnant with more than one baby, and whether different test result thresholds are          needed.

 This Scottish Health Technology Group (SHTG) recommendation is based on       guidance produced by the National Institute for Health and Care Excellence (NICE) in     2022. This guidance was considered and modified following an SHTG adaptation         process.

NHSScotland is required to consider SHTG Recommendations.

What were we asked to look at

Diagnostics Guidance published by NICE in 2022 recommends four placental growth factor (PlGF)-based tests, intended for use alongside standard clinical assessment, to help decide on care for people with suspected preterm pre-eclampsia. SHTG was asked to adapt the NICE guidance for NHSScotland, to inform a Scotland-specific approach to the use of PlGF-based testing. 

Why is this important?

Pre-eclampsia is a potentially serious complication in pregnancy, affecting up to 6% of pregnancies in the UK. Severe pre-eclampsia develops in around 1–2% of UK pregnancies. Approximately 10% of pregnant people will require further assessment and/or monitoring for suspected pre-eclampsia. In 2021, there were 52,584 pregnancies booked for maternity care in NHSScotland. Based on this, an estimated 5,260 pregnant people per year will present with suspected pre-eclampsia in Scotland.

Referred by  

Scottish Government Maternal and Infant Health Policy team