Having Covid-19 may heighten risks of still and premature births.

Having coronavirus around the time of having a baby may increase the chance of stillbirths or premature births, although the overall risks remain low, according to a large UK study.

Scientists say while most pregnancies are not affected, their findings should encourage pregnant women to have jabs as soon as they are able to

The study, published in the American Journal of Obstetrics and Gynecology, was led by the National Maternity and Perinatal Audit which looked at data involving more than 340,000 women who gave birth in England between the end of May 2020 and January 2021.

All women were tested for the virus when they were admitted for births, whether they had symptoms or not.

The study found: 3,527 had positive tests and, of those, 30 had stillbirths after 24 weeks of pregnancy.

Scientists calculate 8.5 per 1,000 women who had a positive test went on to experience a stillbirth compared to 3.4 per 1,000 women who had a negative test.

A total of 12% of women who had a positive coronavirus test gave birth prematurely, or before 37 weeks of full term, compared to 5.8% of women who had negative tests.

It was more common for women who had Covid-19 at the time of birth to be younger and from a black, Asian or other minority ethnic background.

Researchers say a higher risk of stillbirth and prematurity, as well as a greater chance of having a Caesarean section, remained even once factors such as the mother's age, ethnicity, socio-economic background and common health conditions were taken into account.

Babies born to women who tested positive were more likely to need special neonatal intensive care because they were born early and needed more support rather than being infected with coronavirus itself.

Co-author of the paper Professor, Asma Khalil, said it was important for women and healthcare workers to be aware of the potential risks.

She said: "This study is the largest yet in England to describe the pregnancy outcomes in pregnant women who had tested positive for Covid-19 around the time of birth.

"While it is reassuring that the overall increases in the rate of stillbirth and pre-term birth remain low, this study does show that the risk of stillbirth, or premature birth, may be increased in women who have the infection around the time of birth.

"This highlights the importance of Covid-19 vaccination for pregnant women. It reduces the risk not just to themselves, but also to their babies."

Dr Mary Ross-Davie, from the Royal College of Midwives, said: "While the increased risk of a stillbirth or pre-term birth remains low when women have Covid-19 in pregnancy, the important message here is that pregnant women, like all of us, should continue to take precautions to reduce their chances of exposure to the virus including social distancing, hand-washing and mask-wearing.