Pregnant women with suspected pre-eclampsia will now be offered a test on the NHS to detect the condition.

Pre-eclampsia affects some pregnant women, usually during the second half of pregnancy or soon after their baby is born.

It can lead to serious complications if not picked up during maternity appointments, with early signs including high blood pressure and protein in the urine.

In some cases, women can develop a severe headache, vision problems such as blurring or flashing, pain just below the ribs, swelling and vomiting.

Tests have been available to help rule the condition out, but midwives will now use tests designed to pick up a positive diagnosis.

In new draft guidance, the National Institute for Health and Care Excellence (Nice) said midwives caring for pregnant women can use one of four blood tests to help diagnose suspected preterm pre-eclampsia.

They can be used from 20 weeks to 36 weeks and six days, with experts hoping they will pick up the 6% of pregnancies affected by the condition.

The four tests recommended in the guidance are: DELFIA Xpress PLGF 1-2-3; DELFIA Xpress sFlt-1/Xpress PLGF1-2-3 ratio; Elecsys immunoassay sFlt-1/PLGF ratio; and Triage PLGF Test.

The tests measure levels of placental growth factor (PLGF) in the blood.

PLGF is a protein that helps the development of new blood vessels in the placenta.

In pre-eclampsia, levels of PLGF can be abnormally low and could be an indicator that the placenta is not developing properly.

Jeanette Kusel, acting director for MedTech and digital at Nice, said: “These tests represent a step-change in the management and treatment of pre‑eclampsia.

“New evidence presented to the committee shows that these tests can help successfully diagnose pre‑eclampsia, alongside clinical information for decision-making, rather than just rule it out.

“This is extremely valuable to doctors and expectant mothers as now they can have increased confidence in their treatment plans and preparing for a safe birth.”

Dr Mark Kroese, chair of the Nice diagnostics advisory committee, said: “The committee called for further research when it looked at this topic in 2016.

“Following some excellent research, we can now issue draft guidance for four tests which the NHS can use to help diagnose pre‑eclampsia.”