One in five patients receiving treatments through a special lung-bypass machine since July were expectant mothers who have not had their first shots, the NHS said in a statement Monday. Even though women will have concerns about having the vaccine during pregnancy, there exists no link between getting jabbed and an increased risk of miscarriage, premature birth or illness, according to Edward Morris, president of the Royal College of Obstetricians and Gynaecologists.

“There is robust evidence showing that the vaccine is the most effective way to protect both mother and baby against the possibility of severe illness,” Morris said. Over 81,000 pregnant women in England have so far received their first dose, with 65,000 being fully vaccinated.

A mother-to-be who spent nearly in month in critical care said she was hesitant to be vaccinated after experiencing two miscarriages before the pandemic. 

“I completely understand the hesitation not to get vaccinated when you are growing a child inside you,” said Claire, a 33-year-old mother who the NHS identified only by her first name. “After what happened, I can honestly say the risk of not having the COVID vaccine outweighs any doubts about having it.”

More health care and Big Pharma coverage from Fortune:

• Everything to know about Merck’s COVID antiviral pill
• Hospital price lists were supposed to improve transparency—they haven’t
• Florida sees a more than 50% drop in new COVID cases
• 46% of the world’s population has received a COVID vaccine. How your country is doing
• More than 6 million Americans have already gotten a COVID vaccine booster