Mark Bridger was arrested the day after the schoolgirl vanished while playing on her bike near her home in Machynlleth, Mid Wales, on October 1 last year.
The 47-year-old was due to go on trial at Mold Crown Court today.
But the case was adjourned by Mr Justice Griffith-Williams on application of the defence "to make further inquiries".
A new trial date has been set for April 29.
April's parents, Coral and Paul Jones, sat just yards away from the defendant as the case was discussed.
They both wore pink ribbons, which have come to symbolise the ongoing search for their daughter.
Bridger, wearing a blue shirt with rolled-up sleeves and jeans, sat looking straight ahead in the dock, not making eye contact with the couple.
The judge ordered that none of the matters discussed at today's hearing could be reported.
The disappearance of April, who had cerebral palsy, sparked a massive outpouring of support for her family, with hundreds of people joining the search.
The youngster's body has never been found despite a major operation led by Dyfed Powys Police.
Bridger, of Ceinws, is charged with abducting and murdering April, and of unlawfully disposing of and concealing her body with intent to pervert the course of justice.
He pleaded not guilty to the allegations on January 14.