The maternity unit at St Peter’s Hospital is offering a new, non-invasive prenatal test, known as ‘SAFE’, to evaluate with remarkable accuracy whether a pregnancy is at risk of certain chromosomal conditions, such as Down’s syndrome.
Specialist Midwife for Screening and Fetal Medicine, Angie Bowles, explains: “All pregnant women are currently offered a ‘combined test’ between 10 and 14 weeks of pregnancy. This involves a blood test and measurement of the fluid at the back of the baby’s neck (nuchal translucency) during the dating ultrasound scan. The results of these are then combined to estimate the risk of the baby being born with Down’s, Edward’s or Patau’s syndrome. The vast majority of women will get a ‘lower risk’ result (meaning there is less than 1 in 150 chance of their baby having one of these conditions) and they can relax and not worry about it again.”
“However, for a small number, they will receive a ‘higher risk’ result – meaning the chance of Down’s, Edwards or Patau’s syndrome is greater than 1 in 150. When I call these women to explain their results they are obviously upset and anxious and many want to know with certainty if their baby will be born with one of these conditions. Traditionally however, the only other tests available were Amniocentesis or Chorionic Villus Sampling (CVS) – both of which are invasive tests involving passing a needle through the mother’s abdomen and carry a small (1%) chance of miscarriage. Whilst these tests will provide a definitive result, it can feel like an impossible decision to ask women to make.”
“Fortunately we now have an alternative by way of the SAFE test, which is suitable for most women who are identified as higher risk. It is a simple blood test that looks at the baby’s DNA in the mother’s blood, to predict whether or not the baby is affected by certain chromosomal conditions. It is suitable for all single and identical twin pregnancies with a 99% accuracy rate and most women will receive their results back within a few days.”
Whilst the SAFE test has been available privately for a while, it has only recently become available to local women on the NHS. “It’s brilliant this is now freely available for any woman with a higher risk result”, says Angie, “and we are also able to offer it to other women - those who receive a lower risk result but want greater certainty - for a fee. This is a positive development as it means we can offer the test in a controlled way – I take the blood sample, liaise with the laboratory at St George’s Hospital, receive the results and contact the woman. Then, if something is flagged up, I can provide ongoing help and support.”
The new test has proved hugely popular with women using the maternity service at Ashford and St Peter’s Hospitals, with 21 ‘higher risk’ women opting for it in the last three months. “Saving these women the awful decision of whether to opt for an invasive test that carries a small chance of miscarriage, or to spend the rest of their pregnancy waiting to see if their baby has one of these conditions is fantastic”, says Angie. “It’s a very positive development for our maternity service and is making a huge difference to the women we look after.”
Pictured above: Specialist Midwife for Screening and Fetal Medicine, Angie Bowles