Medics have been told to be on alert for blood clots among pregnant women and new mothers amid concern over a 20-year high in maternal deaths.

Some 275 women in the UK died during pregnancy or in the six weeks afterwards in 2020-2022, according to the latest MBRRACE-UK report.

This is the equivalent of 13.56 deaths per 100,000 pregnancies – and the last time deaths reached this rate was in 2004, according to an MBRRACE update published earlier this year.

Now experts have called for action to reduce deaths among pregnant women and new mothers.

Researchers examined the care received by the women who died in more detail and called for strategies and interventions to prevent more deaths.

The figures show that 16% of deaths were caused by blood clots – the leading cause of death among pregnant women and new mothers during pregnancy and the six week afterwards.

In a new report – Saving Lives, Improving Mothers’ Care – experts said that women at high risk of blood clots should get pre-pregnancy counselling and be “appropriately managed” during pregnancy, along with a “restructure” of the existing blood clot risk assessment tool.

The most common causes of death in women who died between six weeks and a year after giving birth were mental health related, including suicide and drug and alcohol use.

As well as making recommendations about blood clot care, the academics also make a series of other demands to improve care, including: better guidance on cancer care for pregnant women; appropriately managed 999 ambulance calls about women who are pregnant; and a call for digital maternity records to include details of a woman’s language needs.

The report also highlights inequalities in maternal deaths.

In 2020 to 2022, black women were three times more likely to die during or up to six weeks after pregnancy when compared with white women, while Asian women were twice as likely to die compared to white women.

And women from the most deprived areas had a two-fold increased risk of dying compared to those in the wealthiest areas, according to MBRRACE-UK, which is co-led by Oxford Population Health’s National Perinatal Epidemiology Unit.

Professor Marian Knight, director of the unit and MBRRACE-UK maternal reporting lead, said: “The UK has had continuous national enquiries into maternity care for more than 70 years, and acting on the recommendations of these enquiries remains as important as ever.

“This latest national enquiry has identified key actions which are needed to ensure women at risk of blood clots are recognised and can access preventative treatment.

“The enquiry also identified opportunities for earlier diagnosis and treatment of cancer in pregnancy by staff recognising when women are describing concerning symptoms not normal for pregnancy.

“(Meanwhile) 999 calls from pregnant women and their families can be better prioritised to ensure seriously unwell women are treated without delay.

“A continued effort is required to ensure equitable outcomes for all women and it is critical that the individual needs of different women are taken into account when planning their care.”

Donald Peebles, national clinical adviser for maternity at NHS England, said: “The NHS has much more to do to ensure all women and babies receive the safe, high-quality care they need, as well as addressing the wider factors that contribute to maternal mortality.

“We are determined to improve maternity services and have rolled out specialist community perinatal mental health teams and Maternal Medicine Networks across England, that help women with pre-existing conditions, or conditions that arise during pregnancy, to quickly get the extra care they need.”