The shots were found to be safe and reduce the risk of stillbirth by 15% after a major review.
Researchers at St George's, University of London, and the Royal College of Obstetricians and Gynaecologists looked at 23 published studies and trials to assess the safety of the shots.
The Pfizer or Moderna vaccines provided 89.5% protection against Covid after the second dose, and the vast majority of the women received them. There was no evidence of a higher risk from the pregnancies.
The professor of maternal fetal medicine at St George's hospital in London wanted to know if the vaccine was safe for pregnant women.
Most of the data on vaccines in pregnancy has been about protecting the pregnant woman from Covid. She said that there is evidence that the vaccines protect the baby. Nature Communications publishes the results.
The majority of pregnant women admitted to UK hospitals are unvaccinated. The number of pregnant women taking the vaccine rose from 23% in August to 54% at the end of last year.
The Joint Committee on Vaccination and Immunisation made pregnant women a priority group for jabs after studies found women were more likely to become seriously ill if they caught Covid while pregnant.
The risk of stillbirth and preterm birth is linked to the infections. The vaccine seems to reduce the risk of stillbirth by protecting against severe disease, but the study found only hints that the vaccine reduced preterm births.
The best way to protect pregnant women and their babies is to get the Covid vaccine.
Edward Morris, the president of the Royal College of Obstetricians and Gynaecologists, said the paper provided further reassurance that Covid vaccine was safe in pregnant women.
Women have been hesitant about having the vaccine due to concerns over the effect on their baby. The vaccine does not increase the risk of adverse outcomes and is the best way to protect women and their babies.
The booster vaccine is recommended for pregnant women. If you get the Covid-19 when you are pregnant, you are more likely to get a severe illness.