Jenny Quiles, from Florida, suffered a brain injury when was she was hit on her way to a doctor's appointment on October 15.
The 36-year-old, who was 33 weeks pregnant at the time, woke up last Wednesday (Oct 29) and went into labour. Four hours later, she gave birth by Caesarean section to a healthy 6lb baby girl.
The baby's father, Angel, has named her Angel Noemi Quiles. Doctors at Bayfront Health St. Petersburgh described the baby – who was born five weeks early – as a 'miracle'.
Along with a photograph of his wife, he wrote: "This is my beautiful wife who got struck by a tow truck carrying our unborn baby girl.
"Protecting her child, she covered her belly like any other mom to be would have done and took the impact to her brain where now both, mom and baby are fighting for there (sic) lives."
He added: "I have nothing for the baby and the expenses we have with me unable to work are in serious need of your support. Anything will help."
He said: "I thought I was going to lose my baby and here we are celebrating the fact that Emmy is born and Jenny is doing better today.
"When Jenny gets out of this, I'm going to tell her thank you, thank you 10,000 times because if it wasn't for her protecting the baby at that time, we wouldn't have the baby or this conversation right now."
Police said truck driver Shaun Downing, 27, is unlikely to face criminal prosecution.