"We just saw the little baby, and the surprise was that she has 12 fingers, like me, like her mummy," Tammy said in the video.
The 27-year-old explained that her sisters, mother and brother also had the mutation, but that her first two children, son Wolf, six, and daughter Saskia, five, who she shares with ex-fiancé Reece Hawkins, 26, were not born with the rare mutation.
"Amy and Emilee had extra fingers when they were born as well, and so did my little brother. So did my mum. It runs in my family," she continued.
"It skips a few people" like it skipped Wolf and Sass, but this baby has 12 fingers. Isn't it crazy?
Last year, the fitness mogul shared a snap of herself as a baby prior to having her extra digits removed.
"Found this pic of my hand when I was a baby lol, count the fingers," she wrote on the photo.
"Me and my older sisters were all born with extras," she added.
She then followed that with a video of her hand currently, writing: "Only five fingers now lol my extra fingers where chopped off when I was born."
WATCH: Tammy Hembrow shares floor exercises to help fans workout at home
In a 2018 video titled '10 things you don't know about me', Tammy explained that the additional fingerss were attached to her little fingers on each hand and had nails, though they had no bones.