Test for Down syndrome linked to miscarriages

From The Telegraph in the UK:

Two healthy babies are miscarried for every three Down's Syndrome babies that are detected and prevented from being born, research has suggested.

The losses are down to the invasive methods used to test for the condition, which affects approximately one in every 1,000 babies conceived, the researchers claim.

They also cast doubt on the advice and risk assessment given to the 6,000 women each year who are offered screening and subsequent testing to assess the health of their unborn baby.

If an expectant mother is deemed to be at risk of carrying a Down's baby following a blood test, she will then go on to undergo an amniocentesis and chorionic villus sampling (CVS) test, which involves inserting a fine needle through the abdomen to either withdraw amniotic fluid or take a tissue sample.

The NHS cites a miscarriage rate of between one and two per cent following the tests, but the researchers, from the charity Down's Syndrome Education International (DSEI), point out that only the number of Down's babies terminated, miscarried or born are recorded, not the number of healthy babies lost.

DSEI chief executive Frank Buckley and Professor Sue Buckley, who conducted their research using a database at London's Bart's Hospital, also point out that 95 per cent of women deemed to be high risk by the blood test will not be carrying a baby with the disorder, yet most go on to have the tests.

"The screening for Down's syndrome has consequences for every pregnant woman," they said. "You cannot look at it as just a search-and-destroy mission focused on babies with Down's alone."

Although they admit that their ratio is only an estimate, they are backed by a number of independent experts who fear inexperienced practitioners may also be to blame.

Professor Kypros Nicolaides, head of the Harris Birthright Centre at King's College Hospital in south London, said the loss of healthy babies was "completely unacceptable".

The Department of Health said the primary aim of screening for the syndrome was to help women make informed decisions about their pregnancies.

A new "combined screen", which is meant to be more effective in assessing who is at risk, is due to be rolled out nationally.

The Buckleys' findings are published in the journal Down's Syndrome Research and Practice.