A mother whose son was born with Down's syndrome after a missed screening is to receive a payout from the NHS.
Edyta Mordel, 33, sued Royal Berkshire NHS Foundation Trust for not detecting the condition in her son Aleksander before his birth in 2015.
She said she and her partner would have aborted the baby if they had known.
Speaking after the judgement, lawyer Richard Money-Kyrle said the couple "adored" their son and had wanted the trust to admit its mistake.
Caroline Ainslie, director of nursing at the trust, said it had since changed its policy regarding screening and "further failsafes have been introduced to improve our services to parents".
The High Court in London heard Ms Mordel initially asked for a Down's syndrome screening but when later asked by a sonographer if she wanted one she declined.
Therefore, a scan was carried out without a screening.
Giving judgment on Tuesday, Mr Justice Jay found Ms Mordel had misunderstood the question.
Aleksander was diagnosed with the condition hours after his birth. In medical records his parents were described as "angry and upset".
The trust contended Ms Mordel had declined the test and regretted her decision.
But the judge concluded both the sonographer and a midwife, who saw Ms Mordel at a later appointment, "failed to discharge their duty" to her by not querying her apparent refusal, since she previously indicated she wanted it.
Ruling in her favour, he said: "The claimant probably would have proceeded to invasive testing had she been told that there was a high risk of Down's syndrome.
"[She] was a relatively young mother and I think that at the end of the day the fear that she might be carrying a child with Down's syndrome would, at least for her, have tipped the balance."
He added the judgement should not be interpreted "as suggesting that the birth of a child with Down's syndrome must be seen as unwelcome".
But he said Down's syndrome screening should be offered to all expectant mothers as "many would wish to exercise their right to proceed to medical termination in the event of a diagnosis".
Speaking after the judgement, lawyer Richard Money-Kyrle said Ms Mordel and her partner, Lukasz Cieciura, "adore Aleksander and remain determined to give him the best life possible".
"This was never about whether or not they loved their son," he added.
"It was always about getting an admission and answers about the failures in Edyta's care to find out what had gone wrong and to ensure that no-one else would suffer from similar failings in the future."
The size of the payout is expected to be a six-figure sum.