Watch the interview with Dr Gill Richardson
There are serious concerns about the numbers of pregnant women who are yet to come forward to receive their Covid vaccination.
The woman in charge of Wales' vaccine rollout Dr Gill Richardson, told ITV News there is now "extensive experience" of use of the Pfizer vaccine throughout the world in countries like America and Canada for pregnant women and said it "is the best thing" for mothers to "do for themselves and their babies".
This follows the rise in the number of unvaccinated pregnant women being admitted to hospital with COVID-19 who are experiencing serious illness.
The Royal College of Obstetrics and Gynaecology (RCOG) and the Royal College of Midwives (RCM) both recommend vaccination as one of the best defences against severe infection.
Dr Richardson warned unvaccinated pregnant women are still being hospitalised, some of whom have needed intensive care.
Dr Richardson said, "So far around 60% of pregnant ladies have had the vaccine, but of course this does mean that four in 10 haven't and that's a concern because we are finding that several of our hospitalisations are for pregnant ladies and some of those sadly have needed intensive care."
A recent study in August revealed similar birth outcomes between those who have had a Covid-19 vaccine and those who have not.
There were no statistically significant differences in the data, with no increase in stillbirths or premature births, no abnormalities with development and no evidence of babies being smaller or bigger, a paper from a team at St George’s, University of London said.
Why is the Covid risk higher in pregnancy?
During pregnancy, a woman's immune system is what is called "down regulated" to enable the mother to carry the child and support the baby.
Dr Richardson said protection against diseases and viruses is particular important during the whole pregnancy, but particularly during last three months of pregnancy.
"It's actually very important that protective vaccinations are accepted, and Covid is clearly one of those."
For any women concerned about the Covid vaccine, Dr Richardson urged them to contact their midwives who are qualified to talk about the programme.
"Also if you want to talk further, then obviously there's your GP or your nurse at your practice so please come forward and have those conversations if you're worried, and hopefully they can reassure you and get you protected."