At 6am on Thursday March 26, Kathryn Fanton woke up her partner, Robin Edrenius, when she realised her waters had broken.
After Ms Fanton started experiencing contractions, Mr Edrenius called an ambulance at 8am.
However, before the paramedics arrived at their home in Stone Cross near Eastbourne, Ms Fanton gave birth to their daughter, who they named Heidi Astrid.
The couple’s first daughter, two-year-old Leia, and the baby’s grandfather, 51-year-old Matthew Layzell, were also at home.
Mr Edrenius cut the baby’s umbilical cord before she and her mother were taken to Eastbourne District General Hospital.
“It escalated quite quickly. I’m on the phone and suddenly a head pops out,” Mr Edrenius said.
“I was in shock. Shortly after, all of a sudden a baby comes out. I have never been so panicked in my life. I didn’t know what to do.”
Mr Edrenius said he “didn’t realise how close it was” when his partner went into labour.
“All of a sudden I was holding my baby in my arms,” he said.
“You hear about people giving birth at home but you don’t expect it to happen to you.”
The couple said their elder daughter Leia was “a little bit in shock”.
Ms Fanton’s stepfather, Matt, said the arrival of Heidi is “a bit of exciting news in these uncertain times”.