What is Down’s syndrome?
Down’s syndrome is often referred to as Trisomy 21 and is caused by the presence of an extra chromosome 21 in the cells of the fetus, sometimes referred to as Trisomy 21, giving a total of 47 chromosomes.
This is a genetic accident that occurs at conception. Overall Down’s syndrome occurs in 1:800 pregnancies, though as can be seen below this risk is increased, more likely, with increasing age. People with Down’s syndrome may have learning disabilities, congenital abnormalities such as heart defects and Alzheimer’s disease later on in life. There is currently no cure for the condition, but there are treatments that can help someone with the syndrome lead an active and independent life.
| Maternal Age | Risk of Down’s Syndrome | Approximate number of Down’s syndrome cases per 9000 pregnancies |
| Less Than 25 years | 1:1500 | 6 |
| 30 years | 1:900 | 10 |
| 40 years | 1:110 | 82 |
| All | 1:800 | 11 |
Photo: Emily Walker
What is a Neural Tube Defect?
There are two kinds of Neural Tube Defects:
Spina Bifida
Babies with Spina Bifida have an opening in the bones of their spine, which usually results in damage to the nerves that control the lower part of the body. This causes weakness and paralysis of the legs.
In addition sometimes the bowel and/or the bladder can be affected. Babies with Spina Bifida are also more likely to have a collection of fluid on the brain – hydrocephalus, which can lead to mental handicap.
Anencephaly
Babies with anencephaly have a large part of their skull missing and the brain is not properly formed. Babies with this problem always die before or very soon after birth.
See the following for more information about Down’s syndrome:
http://www.downs-syndrome.org.uk/
http://www.nhs.uk/Planners/pregnancycareplanner/Pages/Downsscreening.aspx
http://www.babycentre.co.uk/pregnancy/antenatalhealth/testsandcare/screeningfordowns
http://www.bbc.co.uk/health/physical_health/conditions/downssyndrome1.shtml
http://www.womens-health.co.uk/downs.asp
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