Sir Elton John has confirmed his son will have a DNA test to determine whether the singer or his partner David Furnish is the tot's biological father.
The couple welcomed baby Zachary over Christmas (10) with the help of a surrogate mother and the Rocket Man revealed they both contributed sperm samples to the fertilisation process.
They currently don't know which of them is the child's biological father, but Sir Elton has revealed Zachary will have to undergo testing for his medical records.
He says, "Zach will have to know for his medical records. If it's David, I'd be very proud. It wouldn't matter to me - and vice versa."
In an interview with U.S. news show 20/20, which aired in the U.S. on Friday (22Apr11), Sir Elton also revealed their surrogate mother sent them breast milk via courier during their first four months after his birth.
He told talk show veteran Barbara Walters, "The baby's been brought up in Los Angeles for the first four months so we've had the breast milk 'FedEx-ed' from where she (the surrogate mother) is to Los Angeles every day."
Meanwhile the iconic singer says he is grateful his baby boy was born on Christmas Day (25Dec10), because the hospital was so deserted, it allowed the singer time to enjoy the first few hours of fatherhood in private before sharing his secret with the world.
The Rocket Man and his partner David Furnish welcomed their first child, Zachary, via a surrogate and the couple admits his festive birth was a blessing in disguise.
In an interview on U.S. news show 20/20, which aired on Friday night (22Apr11), Furnish says, "It was actually ideal in terms of a secrecy standpoint as well because when we walked into the maternity ward at Cedars-Sinai, it was empty, there was nobody there."
Sir Elton continues, "Nobody wants to have a Christmas baby. People want to have them early or they have them induced or they have a Caesarean, so from a secrecy point of view, it worked in our favor so well."
The new parents are already looking to the future and Furnish insists they are open to the idea of expanding their family: "We're talking about it, but we haven't made up our minds yet. It's not an impossibility."
The couple plans on telling little Zachary all about how he came into the world when he's old enough to understand, and Sir Elton reveals the surrogate mother will always be involved in the child's upbringing.
He says, "She and her family will be still a part of our lives when he's growing up."
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