Post by pinktorontogirl on Nov 29, 2006 15:55:54 GMT
to the thread for the different diagnostic tests available.
Diagnostic tests can tell you for certain if your baby has a chromosomal abnormality such as Down's syndrome, or a structural defect such as spina bifida (screening tests cannot do this on their own). Some diagnostic tests, amniocentesis and CVS for instance, are invasive procedures that carry a risk of miscarriage of around 1%.
Amniocentesis
This test, performed between 16 and 20 weeks of pregnancy, involves a needle being passed through the mother’s abdomen into the uterus, under ultrasound guidance, and a sample of amniotic fluid surrounding the baby is withdrawn. The cells can be tested for Down’s syndrome and other chromosomal and inherited disorders. Results will take about a week if the tests are on the fluid and up to 4 weeks if the cells need to be grown for chromosome analysis. For every 100-200 women who have this test at about 16 weeks it is likely that one will miscarry as a direct consequence of the test.
Chorionic Villus Test
This test, which is usually known as CVS (CV sampling) or CVB (CV biopsy), involves taking a tiny sample of the placenta, also through a needle inserted in the abdomen or cervix.
The advantage of this test is that it can be performed earlier than amniocentesis, between 8 and 12 weeks. The disadvantage is that it carries a slightly greater risk of miscarriage and other complications.
Ultrasound Scanning
This is a technique used routinely in most hospitals to monitor the growth and development of the baby before birth. Scans before 16 weeks are useful for dating the pregnancy (and are able to detect some major malformations), detailed scanning at 18-21 weeks should show up any major malformations as well as some minor ones.
Cordocentesis / Percutaneous umbilical blood sampling (PUBS)
Only offered occasionally, this test involves taking a sample of the baby’s blood from the umbilical cord from about 18 weeks. The same analysis is applied but results may be available slightly quicker.
Diagnostic tests can tell you for certain if your baby has a chromosomal abnormality such as Down's syndrome, or a structural defect such as spina bifida (screening tests cannot do this on their own). Some diagnostic tests, amniocentesis and CVS for instance, are invasive procedures that carry a risk of miscarriage of around 1%.
Amniocentesis
This test, performed between 16 and 20 weeks of pregnancy, involves a needle being passed through the mother’s abdomen into the uterus, under ultrasound guidance, and a sample of amniotic fluid surrounding the baby is withdrawn. The cells can be tested for Down’s syndrome and other chromosomal and inherited disorders. Results will take about a week if the tests are on the fluid and up to 4 weeks if the cells need to be grown for chromosome analysis. For every 100-200 women who have this test at about 16 weeks it is likely that one will miscarry as a direct consequence of the test.
Chorionic Villus Test
This test, which is usually known as CVS (CV sampling) or CVB (CV biopsy), involves taking a tiny sample of the placenta, also through a needle inserted in the abdomen or cervix.
The advantage of this test is that it can be performed earlier than amniocentesis, between 8 and 12 weeks. The disadvantage is that it carries a slightly greater risk of miscarriage and other complications.
Ultrasound Scanning
This is a technique used routinely in most hospitals to monitor the growth and development of the baby before birth. Scans before 16 weeks are useful for dating the pregnancy (and are able to detect some major malformations), detailed scanning at 18-21 weeks should show up any major malformations as well as some minor ones.
Cordocentesis / Percutaneous umbilical blood sampling (PUBS)
Only offered occasionally, this test involves taking a sample of the baby’s blood from the umbilical cord from about 18 weeks. The same analysis is applied but results may be available slightly quicker.