The mother of a child with Down syndrome is suing the British National Health Service, alleging the health system failed to test her child for the condition before birth.

Edyta Mordel, 33, claims her doctors did not perform a prenatal screening for Down syndrome, despite her desire for one. Mordel, who is from Poland, says she would have had an abortion if she knew her now 4-year-old son, Aleksander, had the condition.

“Miss Mordel would have been offered an abortion and her partner, Aleksander’s father, Lukasz Cieciura, agreed they would’ve terminated the pregnancy,” Clodagh Bradley, the couple’s lawyer said, according to the Daily Mail .

The case, which is now playing out in a High Court in London, is legally termed a “wrongful birth” claim because Mordel says she would have ended the pregnancy if the disability were known. She wants $250,000 in compensation because the cost of raising her son continues to rise.

National Health Service authorities say Mordel was offered the screening but declined it. The health system’s lawyer, Michael de Navarro, suggested that she changed her mind, like many other mothers, after learning the procedure carried a 1-in-50 risk for miscarriage.

“I spoke with the midwife about Down’s Syndrome screening. I had informed myself. I had watched a lot of videos and read about screening,” Mordel said in court . “I knew from the start that I would agree on the Down’s syndrome screening and I would not make any other decision.”

In Mordel’s medical records, her doctors wrote “Down’s screening declined.” De Navarro says it is “inconceivable” a medical professional would have written this if it were untrue.

Mordel gave birth to Aleksander at Royal Berkshire Hospital in January 2015. Medical notes indicate she was “very upset and angry” when her son was diagnosed with the disorder.

An increase in prenatal testing for genetic disabilities, like Down syndrome, has caused the number of babies being born with these conditions to fall dramatically. Expectant mothers who receive the diagnosis are choosing abortion instead.

Iceland, which introduced prenatal screenings in the early 2000s, has almost completely eradicated Down syndrome births. According to CBS News , between 1995 and 2011, the United States had a 67% Down syndrome pregnancy termination rate.

The test, which consists of an ultrasound, blood test, and risk factor calculations, is only 85% accurate.