Carried out between 18 and 22 weeks of pregnancy, this scan checks that the baby has developed normally and does not have a major ‘anomaly’ or problem. It won’t detect all problems, but it may show problems in the baby’s brain, heart, kidneys or digestive tract. In most cases it will simply show that your baby is growing well. The scan also checks the position of the placenta.
The sonographer will also check the umbilical cord and the volume of amniotic fluid surrounding your baby.
These measurements indicate whether your baby is developing as expected and act as a double-check on your estimated due date.
As well as developmental checks, the sonographer is looking for specific conditions that may be treatable, or may jeopardise your baby’s survival.
These are the different conditions that are being looked for (the varying detection rates are as documented by the NHS Fetal Anomaly Screening Programme):
If the sonographer detects any problems, you will be referred to a fetal medicine specialist and should be seen within a few days. You will be examined again and it may be that your baby can be treated within the womb or that they will need treatment after their birth.
In a few instances, you may be given the option to end your pregnancy. You will be given counselling and support when making this tremendously difficult decision.
Screening for Down’s syndrome and other genetic disorders is offered to all pregnant women. There are different ways of carrying out screening tests.
Screening tests don’t tell you for definite if your baby has Down’s syndrome – they tell you how likely it is that your baby might have it.
Blood test plus nuchal translucency scan
This involves a blood test and an ultrasound scan. All women should be offered a dating scan between weeks 8 and 14 of pregnancy, and a nuchal translucency scan between 11 weeks, 2 days and 14 weeks, 1 day of pregnancy. If you choose to be screened for Down’s syndrome, the dating scan and the nuchal translucency scan can be carried out at the same time, between 11 weeks, 2 days and 14 weeks, 1 day of pregnancy.
The blood test measures two proteins associated with pregnancy. At the ultrasound scan appointment, the sonographer measures the thickness of the nuchal translucency (a pocket of fluid) at the back of your baby’s neck. The information from the blood test is combined with your age and the nuchal translucency measurement and used to work out your individual chance of having a baby with Down’s syndrome.
Quadruple blood test
If it has not been possible for you to have the combined screening test in early pregnancy, you will be offered a blood test between 14 weeks, 2 days and 20 weeks.
This test is sometimes called the quadruple test, and measures four proteins associated with pregnancy. This information is combined with your age and used to work out your individual chance of having a baby with Down’s syndrome.
result are as follows “lower risk/screen negative” or “higher risk/screen positive”. These are explained below.
If the screening test shows the risk of the baby having Down’s syndrome is lower than the recommended national cut-off level for risk (1 in 150), this is known as having a lower-risk result. A lower-risk result means that you will not be offered a diagnostic test, but it doesn’t mean that there is no risk at all of the baby having Down’s syndrome.
If the result shows the risk of the baby having Down’s syndrome is greater than the recommended national cut-off level for risk (1 in 150), this is known as an increased risk, or higher-risk result. An increased risk means you will be offered a diagnostic test but it does not mean that your baby definitely has the condition.
The appointment will include a discussion with a midwife who will discuss the scan in detail and take the blood sample upon consent
The results will need to be given to your chosen hospital so they are aware
Price for the combined scan and blood test £220
A growth scan is carried out by our qualified sonographers who will measure your baby and give an estimated weight. A full check will also be carried out to check fluid volume and placental site.
Gynaecological scans are carried out by our qualified Sonographer who will examine all of the female reproductive organs. These scans can be carried out in woman who isn’t pregnant and is concerned about any abnormal bleeding, pain or difficulty conceiving
The Harmony Prenatal Test
What is the Harmony test?
It has been discovered that a blood sample taken from the mother at any time from early pregnancy can be analysed for cell-free fetal DNA, which is essentially a marker in the mother’s blood of the DNA of the baby. The result of the simple blood test (Harmony), taken at 10 weeks or later, is predictive to more than 99% in Downs syndrome, 98% of Edwards syndrome and 80% of Patau’s syndrome which will hugely reduce the need for invasive testing by CVS or amniocentesis. This is great news for couples because it eliminates the risk of a miscarriage of the pregnancy. It is important that an ultrasound scan is performed just before the blood test to confirm the pregnancy, and to check that the mother is not carrying twins or more. The Harmony test can be used to check twins as long as it is not an egg donation pregnancy. The Harmony can now be used if the pregnancy is conceived with donated egg. The result of the Harmony is predictive to more than 99% in Downs syndrome.
Why the Harmony test?
This is now one of the most predictive and accurate non-invasive tests to predict the chance of a chromosomal abnormality in a pregnancy (greater than 99% for Downs Syndrome)
For the last ten years’ doctors have been using the results of the Nuchal Translucency Scan to advise pregnant women and their partners on their risk of having a baby with Downs syndrome, or other abnormalities. The Nuchal Translucency Scan looks at the skin fold on the back of the baby’s neck at about 12 weeks. This has been further refined by looking at the nose bone of the baby with an additional blood test to identify two pregnancy hormones. This is the combined test and has achieved a predictive value of about 92%. Women with a high risk have an option to proceed to chorion villous sampling (CVS) or amniocentesis. These are invasive tests that carry a miscarriage risk of about 1:100. This is changing. The Harmony blood test has become available.
Who needs Harmony Test?
Anyone who wants extra reassurance about the normality of the pregnancy can have the test. Women who may need it are those who are anxious about their baby having a chromosomal abnormality such as Downs, Edwards or Patau’s syndrome, Older women (particularly over 40 years) and those who have already had a chromosomally abnormal pregnancy often opt for the test. Those who are at particular risk of miscarriage should they have an amniocentesis or chorionic villous sample also find the test very attractive as it avoids an invasive procedure. It is helpful for those who have had a previous sex chromosome abnormality such as Turners syndrome.
How is the test done?
The mother has to read and sign a consent form and sign a form for data release.
An ultrasound scan is always done first.
This is a simple blood test from the vein in the woman’s arm like any other blood test. There is no risk in having the test.
Two tubes need to be fully filled.
The tubes are immediately packaged and sent to The Doctors Laboratory for dispatch to the USA.
How long does it take to get a result?
The result is usually available within 12-14 days. There is a one in thirty chance that no DNA is obtained. This is not a positive or negative test: it is an unsuccessful test. An offer of a repeat test is made free of charge. This is usually successful.
How is the result expressed?
The result is expressed as a probability. It is a screening test and not a diagnostic test. A result form of a normal test is shown below. A good test result gives a risk of a chromosomal problem of less than 1:10000. A bad result gives a risk of 1:2. A risk of 1:2 requires an amniocentesis or chorionic villous sampling depending on the clinical situation. The couple is counselled about this.
How much does it cost?
The test is currently £450 including the ultrasound scan when done on a weekday or weekend
What happens after the test?
Depending on how many weeks pregnant you are, you will still have the opportunity to have a 12-week scan privately or with the NHS. The focus of the 12-week scan will change as you will already have the result of the Downs syndrome test, so the 12-week scan will look at the baby in detail for structural abnormalities (these may exist without a chromosomal abnormality). You will still have the opportunity to have the later scans, such as the 20 weeks scan, as before. If the Harmony test is negative then it is important that the person conducting the 12-week scan is aware of this. If the test is positive then you should return to The Birth Company or a good NHS unit for further counselling.
Are there problems this test will not detect?
Yes. Structural abnormalities such as Spina Bifida, heart defects and a poorly growing baby will only be seen on scans and often not until later scans. These scans should still be undertaken.
Up to 1 hrs appointment to carry out a full check on mum and baby, including blood pressure, urinalysis, abdominal palpating and listening in to fetal heart. If any issues or concerns arise then we refer to your chosen hospital.
These can be carried out from 6 weeks into the pregnancy and contain full measurements, fetal heartbeat checks and a 2D black and white photo.
These can be carried out at any stage in the pregnancy and contain full measurements and a 2D black and white photo.