An unexpected medical report has derailed the planned sentencing of a teenager for the manslaughter of a young pregnant Hobart woman.
The 16-year-old, who cannot be named due to his age, was expected to be sentenced in the Supreme Court on Wednesday after pleading guilty to running a red light at high speed in a stolen car and ploughing into a hatchback driven by 32-weeks pregnant Sarah Paino, 24.
Emergency services found her dead, with severe neck and chest injuries, but hospital staff were able to deliver her baby son a short time later.
Before Justice Helen Wood sentenced the teenager on Wednesday, defence lawyer Kim Baumeler told the court she had received two days earlier a medical report, voluntarily compiled by a mental health specialist.
"There was a reference to (the youth) having regular psychological counselling," the judge said of the report, which had since been handed to her.
"It seemed to me that might not have been prominent or clear (previously) and I wanted to be sure it wasn't needed to be explored further."
Ms Baumeler applied for the matter to be adjourned so that a more extensive forensic mental health report can be prepared.
"The court must proceed on accurate information and at the present time we don't have it," Justice Wood said, as she reluctantly agreed to the application.
"The report should be obtained to assist the court in sentencing."
The case was adjourned to August 9.
"The timing of the adjournment is extremely unfortunate," Justice Wood added.
"But it must also be said that there is absolutely no fault on the part of the defence as to the way this situation has developed."
Outside court, Ms Paino's father Michael Paino said the family was keen for the case to be over.
The January 22 crash did not injure Ms Paino's two-year-old son who was in the back seat of her car at the time.