Thomas Ridsdill, 40, had to help birth Heather Ridsdill, who was born caul where a piece of membrane – similar to the amniotic sac – covers a newborn baby’s head.
The phenomenon only occurs in around one in 80,000 births.
Mother Kirsten’s waters didn’t break, but she gave birth to baby Heather minutes near Helensburgh after going into labour.
Her husband Thomas called an ambulance, but 13 minutes later his daughter was born.
Kirsten, 38, from Craigendoran in Argyll and Bute, had been at the hospital for a check up on the morning of December 28, 2018.
She was six days overdue, but Kirsten claimed medics told her they did not think she was close to giving birth.
Kirsten said: “We went for a checkup at the hospital in the morning and they didn’t think something was going to happen.
“We went to the shops and then came home.
“Thomas was picking up his car from its MoT and I was in the bath, then I realised I was having contractions and called Thomas to say the baby was coming.”
Thomas, 40, rushed home and called the Vale of Leven Hospital in Alexandria, West Dunbartonshire, but they were unable to assist the couple.
He said: “Kirsten didn’t think we would make it to the hospital so I rang 999 and got her out of the bath and into the bedroom, then they started speaking to me over the phone to give me a hand.
“I got as many towels as I could get, plus a shoelace and a safety pin.”
“The shoelace was for the umbilical cord, but we still don’t know what the safety pin was for.”
Thomas, a lifeboat helmsman, called the ambulance at 1:19pm. By 1:32pm, Heather had been born.
But the father-of-four quickly realised something was not right as he saw his baby girl’s head was still inside the amniotic sac.
Thomas, who called on his experience from saving lives at sea, said: “When Heather was being born I noticed she was still in a bag.
“I didn’t know what it was at the time, it was see-through and halfway out she started crying.
“I just ripped it open, thinking kids shouldn’t have plastic bags over their heads and cleared her mouth.
“That was that, absolutely no difficulties whatsoever.”
After delivering Heather, mum Kirsten was taken to the hospital, where she was told that caul births are good luck.
In medieval times the appearance of a caul on a newborn baby was seen as a sign of good luck.
It was considered an omen that the child was destined for greatness.
Kirsten said: “It was a midwife that told us about the caul birth and that it means good luck.”
She admitted the experience came as a ‘shock’ to her as it happened so quickly and less than a year after her and husband Thomas lost a child to a miscarriage.
Kirsten, a charity volunteer, said: “There was a slight nervousness about it, but it all happened so quickly that I had to deal with it.
“That’s probably why I got so emotional afterwards, but it was a happy release that everything was OK.”
Thomas, who was due to renew his RNLI first aid card around the time of his daughter’s birth, said: “Sleeping in the same bed that night, it was all a bit weird really.
“We were walking around town earlier that day as if nothing was happening, then had a baby an hour later.”