Other tests available during pregnancy
What tests apart from routine ones are available?
Really, there are two types of test:-
Screening tests: such as blood tests and scans. These identify a baby who is more likely to have a defect. They are non-invasive and low risk to baby and mother, but can only make a prediction, not a definite diagnosis. There is a margin for error in the tests, so if they indicate that you are at 'high risk' you will be given the opportunity to have diagnostic tests. Depending which region you live in, you may be offered one of three types of screening tests.
96% of all babies are born perfectly healthy... of the 4% born with an abnormality, roughly half will have a minor variation, i.e. an extra toe, that doesn't affect their quality of life
Diagnostic tests: such as amniocentesis or chorionic villus sampling (CVS), take cells directly from the uterus. They provide more information than screening tests (see above) and are more accurate. However, the disadvantage is that they are invasive. In addition there is no remedy for many of the detectable disorders so termination will be offered to you.
It is worth noting that 96% of all babies are born perfectly healthy. Of the 4% born with an abnormality, roughly half will have a minor variation, i.e. an extra toe, that doesn't affect their quality of life. The rest will have structural malformations such as heart defects, some of which can be corrected after birth. About a quarter are rare single gene defects like cystic fibrosis. Chromosome abnormalities, such as Down syndrome, account for 6 in 1,000 defects.
Again, it is worth noting that their link with maternal age gets so much mention that older mothers often think that the risk is greater than it actually is (see age-related Down syndrome 'risk' chart).
The tests are described briefly below, but please remember that you must take advice from your own qualified medical professional.
Click on the following links to read more:-
- 24-hour nurse-led helpline with confidential healthcare advice and
List of NHS Trusts
NetDoctor.co.uk - information on children's health & diseases
The Fetal Medicine Foundation
Harris Birthright Research Centre (originators of nuchal fold scan)