Flu Shot while pregnant?

My midwife and the antenatal midwifes have said they highly recommend the flu shot while pregnant and want me to do it on my next visit in 3 weeks, by then I will be 35 weeks. Does anyone know if it harms the baby in anyway. The midwifes also said they have had pregnant women in the intensive care unit with the flu.
My mum is freaking out and said do some research on it since she is into the all natural stuff, I thought I would ask you all first on your thoughts.....
Thanks 😉