The Duchess of Cambridge is unlikely to have been induced before giving birth to her daughter, experts have said.
Pat O'Brien, a consultant obstetrician at University College Hospital, said that because of the speed with which the baby was delivered, it is more likely the Duchess went into labour naturally.
He said: "The fact that she went into hospital at around 6am and had the baby by 8:34am would not imply that she was induced at all.
"Second time labours tend to be quicker than first time labours. Everything tends to go faster. The dilation stage is quicker, the pushing stage is usually quicker and easier as well, and the baby comes out more quickly.
"You would expect it to be an easier labour anyway."
Doctors at the Lindo Wing may have chosen to induce the Duchess later this week if she had not gone into labour naturally, as she was already around nine days overdue.
The fact that the Duchess went into hospital at 6am - 15 minutes later in the day than during her first pregnancy and at a time when few photographers were present - also gave rise to suspicions that she may have been given a little help.
But Mr O'Brien said that given when the Duchess gave birth, it was more likely she went into labour overnight.
He said: "If someone goes into hospital in the morning to have labour induced then very often labour doesn't get started until the evening."
A source whose children were born at the Lindo Wing said last week that the doctors do not usually wait for more than a week before they induce expectant mothers.
She said: "They will probably already have been in touch with Kate and talked about which day would suit her best to go in and be induced if the baby didn't arrive in the next couple of days."