London, Jan 14 (IANS): Women who have Covid-19 towards the end of their pregnancy are vulnerable to birth-related complications, according to a study.

They are more likely to have complications than those who get Covid-19 in the earlier stages of pregnancy or who haven't had Covid-19 at all, said a team of researchers from Universities of Edinburgh, Glasgow, Aberdeen and others.

The findings, published in the journal Nature Medicine, show that preterm births, stillbirths and newborn deaths are more common among women who have the virus 28 days, or less, before their delivery date.

The majority of complications, which also include Covid-related critical care admissions, occurred in unvaccinated women.

Researchers said more should be done to increase vaccine uptake in pregnant women, whose vaccination rates are much lower than those of women in the general population.

"Our data add to the evidence that vaccination in pregnancy does not increase the risk of complications in pregnancy, but Covid-19 does," said Sarah Stock from the University of Edinburgh's Usher Institute.

"Covid-19 vaccination in pregnancy is crucial to protect women and babies from preventable, life-threatening complications of Covid-19," added Stock, who is also a consultant obstetrician.

The team analysed data relating to all pregnant women in Scotland. It included more than 87,000 women who were pregnant between the start of vaccination uptake in December 2020 and October 2021.

The team analysed data on extended perinatal deaths - defined as death of a baby in the womb after 24 weeks of pregnancy, or in the first 28 days after birth.

They found that the extended perinatal death rate among babies born within 28 days of their mother developing Covid-19 was 23 per 1,000 births.

All baby deaths occurred to women who were unvaccinated against Covid-19 at the time of infection.

Some 17 per cent of babies born within 28 days of their mother developing Covid-19 were delivered prematurely, more than three weeks before their due date.

Admission to hospital and critical care were also significantly more common in pregnant women with Covid-19 who were unvaccinated at the time of diagnosis than in vaccinated pregnant women - 98 per cent of women with Covid-19 during pregnancy who were admitted to critical care were unvaccinated.

The team also monitored complication rates in women who received a Covid-19 vaccination during pregnancy and found vaccination safe during pregnancy.