Health officials have launched an investigation after a computer error in a Sheffield hospital led to 150 pregnant women being wrongly advised that their babies were at low risk of developing Down's Syndrome.
The error, which remained undetected for four months, occurred in a computer controlled machine used by the Northern General Hospital NHS Trust to analyse blood test results taken during the early stage of pregnancy.
According to the Community Health Association for Sheffield, a programming error led the machine to miscalculate the age of the women from their dates of birth. This meant that women at a higher risk of having a Down Syndrome baby were wrongly diagnosed as being at low risk and were not offered further tests.
Janet Beyleveld, chief officer of the health association, said she would be pressing the hospital to investigate whether the problem, which affected results from 4 January, may have resulted from year 2000 problems.
The programming error was discovered in the hospital's Pathlan system, which calculates the likely risk of carrying a child with Down's Syndrome, from an analysis of blood test results, the patient's age and other variables.
The women now face further tests that can create higher risk of miscarriage during the later stages of pregnancy. The hospital said it was investigating the error, but refused to comment on whether it related to year 2000 difficulties.