Offer screening in pregnancy for chromosome disorders earlier, say experts

Expectant mothers should be offered earlier screening for rare chromosomal conditions, the UK National Screening Committee (UK NSC) recommends.

Edwards' syndrome and Patau syndrome are the two most common forms of trisomy after Down's syndrome. Although together these conditions affect only around two in every 10,000 live births in the UK they are a frequent cause of miscarriage. Where pregnancies are carried to term, only a small proportion of children will survive beyond early infancy and all will have severe developmental problems.

Edwards' and Patau's syndromes are currently usually detected during a scan at around 20 weeks, but the UK NSC has now recommended that women be offered a test earlier, during the first trimester.

Dr Anne Mackie, director of programmes at the UK NSC, said that the recommendation 'would give women access to support and enable them to make important choices at an earlier stage of their pregnancy'.

The new test could be included as part of the existing screening programme for Down's syndrome, which includes a blood test in the first trimester and an ultrasound at around 12 weeks to assess the amount of fluid at the back of the fetus' neck. If either Edwards' or Patau's syndrome are suspected, this could then be followed up with more invasive tests such as amniocentesis, to confirm the diagnosis.

According to BBC News, the recommendations have already received ministerial approval in England and are also likely to be adopted in the rest of the UK.