Two new tests to help rule out pregnancy complications look set to be recommended for NHS use, having originally been excluded due to safety concerns.
The National Institute for Health and Care Excellence said it would now be recommending the Triage PIGF test and the Elecsys immunoassay sFlt-1/PIGF test in draft diagnostics guidance.
The tests – used to rule-out potentially life-threatening pre-eclampsia – were not included in an original draft due to concerns they could lead to women being incorrectly diagnosed with the condition.
Both tests measure levels of placental growth factor (PIGF) in the blood, which can be abnormally low in cases of pre-eclampsia.
The Elecsys immunoassay sFlt-1/PIGF test also measures a protein thought to hamper the formation of blood vessels, with higher than normal levels expected to show up in cases of pre-eclampsia.
“Until now there have been no tests which can be used to confidently rule-out pre-eclampsia”
Until now there have been no tests that can be used to confidently rule out pre-eclampsia, which means pregnant women suspected of having the condition undergo increased monitoring and may be admitted to hospital.
NICE experts concluded the tests could be safely used to rule out pre-eclampsia, but were initially worried that women with positive test results would automatically be assumed to have the condition – which is not always the case.
“If a PIGF result was positive for rule-in of pre-eclampsia great emphasis may be placed on this result rather than clinical assessment,” said Mirella Marlow, programme director for device and diagnostic systems at NICE. “This could result in the unnecessarily early delivery of the baby.”
However, the draft guidance now advocates the tests providing they are not used on their own to diagnose pre-eclampsia.
Laboratory reporting of test results must make this clear and health professionals should be trained to use the tests correctly, the draft guidance stressed.
Ms Marlow added: “The committee concluded that careful laboratory reporting of PlGF-based test results combined with targeted medical education is important and should prevent situations in which results of a test designed to make a rule-out decision start to be used to make a diagnosis.”
“Until now there have been no tests which can be used to confidently rule-out pre-eclampsia,” she noted.
Two other tests were also considered but were not recommended for routine use in the NHS. These were the DELFIA Xpress PIGF 1-2-3 test and BRAHMS sFlt-1 Kryptor/BRAHMS PIGF plus Kryptor PE ratio.
The closing date for comments on the draft guidance is 11 January. Final guidance is expected in May.