A mother who had a disabled baby after antenatal scans at Bedford hospital failed to pick up that he had spina bifida has won a £515,000 pay-out.
NHS lawyers admitted at the High Court that scans should have pinpointed her son's condition.
Bedford Hospital NHS Trust also conceded that, had the mother learnt the truth, "she would have had a termination if properly counselled".
The NHS trust admitted breach of duty and has agreed an interim payment.
The boy, who cannot be identified, is now five years old and the £515,000 payment will enable his mother to buy a new home specially adapted for her son's needs.
That will only be a fraction of the NHS trust's final damages bill, which will have to be assessed by a judge in the future if final settlement terms are not agreed before then.
Jalil Asif QC, for the NHS trust, told Mrs Justice Swift that "complex issues" still had to be resolved,
He said it was the trust's case that it could not be held legally responsible for birth defects, other than spina bifida, which could not have been detected while the boy was still in his mother's womb.
The judge, sitting at London's High Court, gave directions for exchange of medical evidence, but the court heard the case is unlikely to come to a full hearing until 2012 at the earliest.