The Queen's surgeon-gynaecologist, Dr Marcus Setchell, was approaching the age of retirement when he received a call from the royals last year asking him to deliver the Prince William and Kate Middleton's baby.
Mr Setchell, who will turn 70 in October and plans to retire at the end of the year, has also joked that he might return from retirement to deliver the other babies that the royal couple are believed to be planning.
"Marcus says he will retire after the baby is born but because he knows they are planning more children, he will probably have to take time out of his retirement to deliver those too," a source close to Marcus told the Mirror.
Dr Setchell was on hand to look after Kate when she suffered from hyperemesis gravidarum at the beginning of her pregnancy.
Dr Setchell, who is the Queen's surgeon-gynaecologist, delivered Sophie, Countess of Wessex's two children, Lady Louise Windsor and James, Viscount Severn. He also cared for Sophie following her ectopic pregnancy in 2001. He also performed the Duchess of Cornwall's hysterectomy in 2007.
William and Kate's baby, who will become third in line to the throne, will be delivered at the private Lindo Wing in St Mary’s Hospital, Paddington, London. It is the same hospital where Princess Diana gave birth to Princes William and Harry.
The Lindo Wing, within one of London's NHS-run teaching hospitals, also welcomed Zara Phillips and Peter Phillips into the world. According to the hospital's website, a normal delivery package costs £4,965 for the first 24 hours, rising to £6,420 for the first 24 hours of a Caesarean birth.
"The baby is due in mid July," a source told HELLO!.
"When he or she is born the announcement including the baby's gender, weight and time of birth will be posted on an easel on the forecourt of Buckingham Palace.
"The baby will be named at a later date."
William plans to be at his wife's bedside and Kate is said to be keen on a natural birth.
After the birth William plans to take two weeks paternity leave from RAF Valley in Anglesey. New mum Kate will take maternity leave, although it is not known how much time she will take off.
Watch: Prince William takes George to meet his sister
It's a little princess!