Letter: 'Elderly' mothers and Down's syndrome tests

Sir: As the consultant in charge of a unit that has always striven to provide, on the NHS, the very best of prenatal diagnostic services, I was saddened to read the comments of your correspondent Janet Daniels (Letters, 18 August).

At a time of financial stringency we have taken the as yet uncommon step of offering the triple screening test for Down's syndrome to all our expectant mothers. This test will, as Mrs Daniels correctly states, increase the detection rate of Down's syndrome overall by allowing the identification of a higher risk population, some of whom might wish to proceed to the secondary definitive, but invasive, investigation of amniocentesis.

Screening by this means is obviously of particular importance to younger, hitherto unscreened, women and it also enables us to reduce potentially the number of amniocenteses in women over 35 if favourable triple screening results are obtained.

We have never ceased offering amniocentesis to women over 35 but find that following the necessary counselling that we provide for a substantial number of such women, particularly those around the age of 35, they prefer a non- invasive pre-screening test in the first instance - just as a substantial number of women in the 'older' (40-plus) group who are at higher risk opt for the definitive procedure of amniocentesis as their primary investigation, despite the associated risk of miscarriage. In order to improve the service offered to these latter women we were one of the first units in the UK to offer early (12-14 weeks) amniocentesis.

The prenatal diagnostic counselling and investigative services offered at Addenbrooke's are as good as any in the UK and, I can assure you, are not governed in any way by financial considerations.

Yours sincerely,

PETER MILTON

Consultant Obstetrician and

Gynaecologist

Rosie Maternity Hospital

Cambridge