Letter: Questions on antenatal screening for Down's syndrome

Sir: Your article on antenatal screening, and specifically the 'triple test' for Down's syndrome, highlighted the concern over 'false positive' results. Here in East Sussex, where we offer the 'triple test' to all mothers, the laboratory carrying out the tests has an excellent 'false positive' rate for Down's syndrome - just 2.9 per cent of the total tests.

All mothers are informed of the test and may refuse it if they wish - around 65 per cent accept. Although anxiety is increased if the result is 'screen positive', we do our best to ensure that this is kept to a minimum. Results are given face-to-face by the midwife and an appointment is made to discuss the result with a consultant the following day; amniocentesis is available at the same time if required.

The question is whether it is worth making so many women anxious for the sake of detecting one affected pregnancy. Our figures show that for every mother who has to make a decision about whether to continue her Down's syndrome-affected pregnancy, 21 other mothers are made unnecessarily anxious by a 'screen positive' result that is subsequently found to be normal. We try to minimise this anxiety, but the decision to be screened in the first place means there is a price to pay for choice. For younger women, this is a choice they were previously denied.

Yours faithfully,

MARY PIGGOTT

Triple Test Co-ordinator

Department of

Chemical Pathology

East Sussex Health Authority

Brighton, East Sussex

26 January