It's lovely seeing those first grainy images of your baby on a scan. But the main purpose of scans, tests and checks is to make sure your baby is developing normally. Here's what you're likely to have and why:
Routine tests
Most pregnant women will be offered these:
Dating scan
When? 8-14 weeks.
Why? To work out your baby's age. You'll need it if you're having any of the screening tests as it's important to know your baby's age for these to be reliable. The scan will also tell you if you're having twins and if they're identical.
Triple or quadruple blood test
When? 16-18 weeks.
Why? To evaluate your baby's risk of conditions such as spina bifida and Down's syndrome. You'll be given a number such as 1 in 750. This means for every 750 pregnant women, one in your risk bracket
will have a baby with Down's. If you are high risk (1 in 250 or less) you'll be offered a diagnostic test which will give you a definite answer.
Anomaly scan
When? 18-22 weeks.
Why? To look at your baby's
developing major organs. If there's something unusual you'll be
referred for further scans.
Other tests you might have
In some areas of the UK you'll be offered these:
Nuchal fold translucency scan When? 11-14 weeks.
Why? This ultrasound scan
measures the depth of fluid under the skin at the back of your baby's neck, as babies with Down's have more fluid here. Less than 4mm of fluid is considered low risk, while 4-7mm is high risk. If your hospital doesn't offer this, you can ask to have it at another hospital or privately.
- The combined test combines the scan with a blood test.
- The integrated test is carried out in two stages. The first stage combines a nuchal scan and a blood test. Then the quadruple blood test is done at 15-16 weeks. The results of both stages are put together.
Special tests If your midwife or doctor thinks you're at risk of a problem, you'll be offered these:
CVS (chorionic villus sampling) When? Between 11-14 weeks.
Why? This diagnostic test looks for conditions including Down's, sickle cell and thalassaemia. You'll be given a local anaesthetic, then a fine needle is pushed through your tummy to collect a sample of cells from your placenta. There's a very small risk of miscarriage.
Amniocentesis This diagnostic test is done from 15 weeks to check for things such as Down's syndrome. Using ultrasound, a fine needle is put through your tummy to collect some amniotic fluid. Cells from the fluid are then tested. There's a slight risk of miscarriage - about 1%.
Sickle cell and thalassaemia test Sickle cell is an inherited condition that affects the red blood cells' ability to carry oxygen around the body. Thalassaemia is a
condition that causes life-threatening anaemia. This blood test finds out if you're a carrier of either. If you are, the baby's dad will need the test too, as if you're both positive there's a risk your baby could
develop the condition. If so, you'll be offered a diagnostic test.
Cystic fibrosis carrier test This test will only be offered if there's a family history of cystic fibrosis. In some places it's done with mouthwash; in others a blood sample is taken. If your test is positive, the baby's dad will also be tested as if you're both positive your baby has a one in four risk of the disease. If this is the case, you'll be offered a diagnostic test.
- Remember, you don't have to have any tests if you'd prefer not to. In some cases they can cause unnecessary worry, so if you're unsure, talk to your partner, midwife or GP first.
| JARGON BUSTING Confused by all the different names and terms used to describe your tests? Then check our quick jargon-buster… SCANS look for any potential problems as well as dating your pregnancy. SCREENING TESTS tests let you know whether your baby is at higher than usual risk of having a problem. If so, you’ll be offered a diagnostic test so you can get a definite answer. DIAGNOSTIC TESTS are the only way to find out for definite if your baby has a condition such as Down’s syndrome. There’s a small risk of miscarriage if the test involves inserting a needle into your abdomen. |
- Contact Antenatal Results and Choices for advice on 020 7631 0285 or visit www.arc-uk.org.
- For information on Down’s syndrome, contact the Down’s Syndrome Association on 0845 230 0372 or visit www.downs-syndrome.org.uk.
