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In draft diagnostics guidance published recently for public consultation NICE has said that further research is needed on 2 promising new tests that could help diagnose a potentially serious complication of pregnancy.

The Triage PlGF test (Alere International) and the Elecsys immunoassay sFlt-1/PlGF ratio (Roche Diagnostics) used together with clinical judgement and other diagnostic tests are designed to help diagnose suspected pre-eclampsia in the second and third trimesters of pregnancy.

Pre-eclampsia is characterised by high blood pressure (hypertension) and proteinuria which occurs when the kidneys leak protein into the urine. The presence of either hypertension or proteinuria during pregnancy can also indicate a risk of developing pre-eclampsia.

Pre-eclampsia is thought to be caused when the placenta doesn’t develop properly, because of a reduced blood supply to it. If it’s not treated, there is a risk that the mother can develop potentially life-threatening fits called eclampsia.

Pre-eclampsia can lead to liver, kidney and lung failure, problems with blood clotting and stroke. It is also thought that women who develop pre-eclampsia during pregnancy may have a greater risk of cardiovascular disease later in life. Hypertension and pre-eclampsia can affect the fetus, increasing the risk of its growth slowing or stopping, premature birth, or stillbirth.

The only cure for pre-eclampsia is delivery of the baby; the decision on when to deliver is based on clinical symptoms which indicate risk to the mother or baby, rather than the presence of pre-eclampsia alone.

The Triage PlGF test and the Elecsys immunoassay sFlt-1/PlGF ratio measure levels of placental growth factor (PlGF) in the blood. PlGF is a protein involved in the development of new blood vessels in the placenta. In pre-eclampsia levels of PlGF can be abnormally low. In normal pregnancy, PlGF levels rise and peak at 26 to 30 weeks, so when PlGF levels do not rise during pregnancy this may be an indicator that the placenta is not developing properly.

The Elecsys immunoassay sFlt-1/PlGF ratio also measures soluble FMS-like tyrosine kinase-1 (sFlt-1), a protein which is thought to disable proteins associated with blood vessel formation, such as PlGF. In women who develop pre-eclampsia, the levels of sFlt-1 are thought to be higher than those seen in normal pregnancy.

Professor Carole Longson, NICE Health Technology Evaluation Centre Director, said: “There are currently no tests which can be used to confidently rule-out pre-eclampsia. This means pregnant women with suspected pre-eclampsia often require increased monitoring or admission to hospital, which can be inconvenient and can cause anxiety.

“Having considered the evidence presented to it the Committee concluded that PlGF-based tests could be used to safely rule-out pre-eclampsia in women between 20 weeks gestation and 34 weeks plus 6 days gestation. This could potentially allow women who have pre-eclampsia ruled-out to receive community care instead of being admitted to hospital for observation.

“However, the Committee heard that the interpretation of positive test results to rule-in pre-eclampsia is more difficult. The Committee thought that if a PlGF result was positive for rule-in of pre-eclampsia, great emphasis may be placed on this result, rather than clinical assessment, which could result in the unnecessary early delivery of the baby.

“The Committee felt that because PIGF-based testing could not be limited only to the rule-out of pre-eclampsia further research is needed on the use of PlGF-based tests for the rule-in of pre-eclampsia in women presenting with suspected pre-eclampsia between 20 weeks gestation and 34 weeks plus 6 days gestation, before the tests can be recommended for routine use.”

The draft diagnostics guidance also recommends that further research is carried out on the use of repeat PlGF-based testing after a negative test result in women presenting with suspected pre-eclampsia.

Two further tests were considered as part of this assessment. The draft guidance does not recommend the DELFIA Xpress PlGF 1-2-3 test (Perkin Elmer) and BRAHMS sFlt-1 Kryptor / BRAHMS PlGF plus Kryptor PE ratio (Thermo Fisher Scientific) for routine adoption in the NHS. Further evidence to show the clinical effectiveness of these tests including diagnostic accuracy and analytical validity is needed.

For more information call the NICE press office on 0300 323 0142/pressoffice@nice.org.uk or out of hours on 07775 583 813.

Notes to Editors

1. The draft diagnostics guidance on tests to aid the assessment of suspected pre-eclampsia is available on the NICE website. The closing date for comments on the draft guidance is 19 November 2015.
2. NICE guideline on antenatal care (2008; CG62) recommends measuring blood pressure and testing urine for proteinuria to screen for pre-eclampsia at each routine antennal visit.
3. The NICE pathway on pre-eclampsia describes the assessment and treatment of women at risk of pre-eclampsia or with pre-eclampsia. The NICE guideline on hypertension in pregnancy was used to create the pathway (2010; CG107).

About the NICE Diagnostics Assessment Programme 

1. For further information about the NICE diagnostics assessment programme see Developing NICE diagnostic technologies guidance  
2. Topics to be considered by the Programme are routed through the related Medical Technologies Evaluation Programme. Further information about this can be found at Developing NICE medical technologies guidance

About NICE

The National Institute for Health and Care Excellence (NICE) is the independent body responsible for driving improvement and excellence in the health and social care system. We develop guidance, standards and information on high-quality health and social care. We also advise on ways to promote healthy living and prevent ill health.

Our aim is to help practitioners deliver the best possible care and give people the most effective treatments, which are based on the most up-to-date evidence and provide value for money, in order to reduce inequalities and variation.

Our products and resources are produced for the NHS, local authorities, care providers, charities, and anyone who has a responsibility for commissioning or providing healthcare, public health or social care services.

To find out more about what we do, visit our website:www.nice.org.uk and follow us on Twitter: @NICEComms.