The research also found that 98 per cent of all pregnant women with Covid-19 who were admitted to critical care were unvaccinated.

Preterm births, stillbirths and newborn deaths were also more common among women who had the virus 28 days or less before their delivery date, compared to background rates.

All the women whose babies died had not been vaccinated against Covid-19 at the time of infection.

Experts stressed that it is not possible to say if Covid-19 contributed directly to the deaths or preterm births as they did not have access to detailed clinical records for individual women.

Just under a third (32 per cent) of all pregnant women who gave birth in October 2021 were double-jabbed, compared with 77 per cent of the general female population.

Experts said the findings, which are part of the Covid-19 in Pregnancy in Scotland (Cops) study, highlight the importance of getting the vaccine.

Cops co-lead Dr Sarah Stock, of the University of Edinburgh’s Usher Institute , who is also a consultant obstetrician, said: “Our data add to the evidence that vaccination in pregnancy does not increase the risk of complications in pregnancy, but Covid-19 does.

“Covid-19 vaccination in pregnancy is crucial to protect women and babies from preventable, life-threatening complications of Covid-19.”