The actress, who plays Alicia Metcalfe in the rural soap, revealed that baby boy Freddie's heart stopped beating during her contractions.
Anderson gave birth to her first child with husband James Shepherd earlier this month.
She told Hello! magazine: "Every time I was having a really intense contraction, his heart was just stopping as the cord was tightening.
"It was the scariest time of our lives. They knew they had to get him out and said if nothing happened in the next five minutes I'd need to go to theatre for an emergency C-section."
Recalling the moment she first held her son, Anderson said: "When he was born all I could feel was overwhelming love for him. When they put him on my chest and I could see him for the first time, it was amazing.
"I would relive that moment over and over again. Freddie is surrounded by so much love. We are so lucky."
The 30-year-old, meanwhile, admitted that she is surprised by her weight loss since her pregnancy, adding: "I had a very compact bump and carried Freddie neatly across the front, which people say is more common with boys.
"I just ate very healthily throughout and the weight that's gone is Freddie. I'm breastfeeding as well, but I didn't think it would come off so quickly."