The Duke and Duchess Of Sussex recently announced their delight at having their first child together.
And although he is currently estranged from the couple Thomas, 74, is happy for them both.
He told The Mail on Sunday: “I was sitting in line waiting to cross the border when I heard the baby announcement on the car radio.
“The first thing I thought about was holding Meghan in my arms as a newborn 37 years ago.
“I thought, “My baby is having a baby.” It was a very proud moment.
“I was filled with love, joy and happiness for both my beautiful daughter and my son-in-law. A new baby is a blessing and I look forward to seeing a little Meghan or a little Harry.”
And their baby joy took him back to the time when Meghan was born during the early hours of August 4, 1981, in Canoga Park hospital in the suburbs of Los Angeles.
He added: “It was in the middle of the night when Meghan was born by caesarean section. Doria [Meghan’s mother] was sleeping [anaesthetised] and so I was the first person in the world to hold Meghan.
“When they handed her to me and I held her in my arms for the first time it was love at first sight. She was the most beautiful baby.
“Meghan winked at me and I fell in love and have never stopped loving her from that day forward.”
He became estranged from his famous daughter just before the Royal Wedding in May after hanging up on Prince Harry.
The two fell-out after Harry chastised him for co-operating with paparazzi posing being ‘fitted’ for a wedding suit.
And as a result he did not attend the wedding to walk his daughter down the aisle St George’s Chapel, Windsor, before millions of television viewers.
It is understood that he was not personally informed that Meghan is expecting her first child with the British prince.
However, he still wants to wish the couple good wishes after their baby news and would like to congratulate them.
“I wasn’t surprised by the baby announcement. Meghan loves children and she and Harry have been talking about wanting a family from the start. I’m delighted for them both,” he added.
“She’s always been wonderful with children and most of her friends have families so she’s used to being around kids. She will make a fantastic mother.”