The tests offered include:
- Infectious Diseases – HIV, Hepatitis B and Syphilis
- Sickle cell anaemia and thalassaemia
- Screening for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome
- The 20-week scan
Infectious Diseases – HIV, Hepatitis B and Syphilis
All women booking for antenatal care will be offered screening blood tests identify if you have any of these infections. This is because if these conditions are left undetected, they may be harmful to you and your baby. Although all blood tests in pregnancy are not compulsory, screening for Infectious diseases is strongly recommended. Early detection of these conditions drastically reduces the chance of your baby being born infected with the 3 conditions. For example, if we can identify that a mother is Chronic Hepatitis B positive then we can facilitate a baby to undergo the vaccination schedule which will significantly reduce the risk of transmission.
Sickle Cell and Thalassaemia Anaemia
All women who plan to have their baby at Wirral Women’s and Children’s Hospital will be offered screening for Sickle Cell Anaemia and Thalassaemia in pregnancy. Sickle Cell and Thalassaemia are genetic blood disorders which affect the way that red blood transport oxygen around the body. You yourself may be a healthy carrier of the disorder but not necessarily be affected by the disease. If the father of the baby is also a carrier of the gene, then you have a 1 in 4 chance of having a baby with a Haemoglobinopathy disorder. If you are found to be a carrier of the gene, then the baby’s farther will also be offered a test so that we can calculate the chance of the baby being affected and offer you the right support and information about the next steps.
Pregnancy dating scan
The pregnancy dating ultrasound scan:
- checks your baby’s heartbeat
- finds out if there is more than one baby
- measures your baby to estimate how many weeks’ pregnant you are
- checks for some conditions in your baby that might be seen at this stage
The pregnancy dating ultrasound scan is part of the combined screening test for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome, if you choose to be screened
The scan is usually offered between 10 and 14 weeks of pregnancy, the exact date will depend on whether or not you plan to take the combined screening test for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome.
Screening for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome
Some people want to find out if their baby has Down’s syndrome, Edwards’ syndrome or Patau’s syndrome and some do not. Screening for these conditions is your choice.
This short animation explains screening for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome in pregnancy.
You can choose to have
- no screening
- screening for Down’s syndrome only
- screening for Edwards’ syndrome and Patau’s syndrome only
- screening for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome
If you choose to have screening for any of these conditions, you will be offered the combined screening test. The test includes an ultrasound scan and a blood test from you and you must attend for both of these within the required screening timeframe. This is because the scan can only be done when your baby is a certain size and the bloods are only valid within a specific timeframe. The information from the scan and the blood test is combined to work out the chance of you having a baby with Down’s syndrome, Edwards’ syndrome or Patau’s syndrome.
Sometimes it is difficult to take the nuchal translucency measurement (collection of fluid under the skin behind the fetal neck) of your baby during the scan. This might be because your baby is lying in an awkward position or you are above average weight. If this is the case you will be asked to change position and/or move around and one further attempt will be made at the same appointment.
If it is not possible to complete the scan part of the combined test because of the reasons above, or because your pregnancy is too advanced your choices of screening are:
- The Quadruple (Quad) test – this is a blood test to screen for Down’s syndrome and is usually taken between 14 weeks and 2 days and 20 weeks of pregnancy. The Quad test is nearly as accurate as the combined test.
- Screening for Edwards’ syndrome and Patau’s syndrome, which is offered as part of the 20-week scan.
Screening test results for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome
These tests do not tell us whether your baby definitely has Down’s, Edwards’ or Patau’s syndrome. They simply tell us whether you are at high chance (defined as a chance higher than 1 in 150) or low chance of having a baby with Down’s, Edwards’ or Patau’s syndrome.
If the screening test shows that you are in the low chance group you will usually receive a letter informing you of this within two weeks of the test.
If the screening test shows that you are in the high chance group, the specialist Screening Midwife will contact you by phone within one week of the test to discuss the results and the options for management with you. This will include the offer of a diagnostic test, either Chorionic Villus Sampling (CVS) or an amniocentesis to find out if your baby has Down’s, Edwards’ or Patau’s syndrome or not. These tests both have a small risk of miscarriage.
Women receiving high chance results for screening tests will also be offered non-invasive prenatal testing (NIPT). The NIPT test looks for fetal DNA in the maternal circulation from a sample of mother’s blood. This is a screening test, not a diagnostic test, but the detection rate is over 99% compared to the combined screening test which has a detection rate of 86%. There is no risk of miscarriage. The screening test result shows whether there is a low or high chance of your baby having Down’s syndrome, Edwards’ syndrome or Patau’s syndrome. The results are usually available within seven working days of the blood sample being taken.
The 20-week scan
This scan is a screening test that takes place between 18 weeks and 20 weeks plus 6 days of pregnancy. The scan looks for 11 physical conditions in your baby.
This short video explains screening for 11 physical conditions in pregnancy.
Screening is your choice. You do not have to have the 20-week scan. Some people want to find out if their baby has one of the 11 physical conditions and some do not. When deciding whether or not to have the 20-week scan it is important to understand that scans cannot find all conditions. There is always a chance that a baby may be born with a condition that could not be seen on scan.
If you choose to have this scan, you may need to make important personal decisions based on the results. Whatever you decide, you will be supported by your healthcare team.
To check for the 11 conditions, the scan looks in detail at your baby’s:
- abdomen
- bones
- brain
- face
- heart
- kidneys
- spinal cord
In most cases, the scan will show that your baby appears to be developing as expected and does not have any of the 11 physical conditions screened for.
You will always be told if anything unexpected is found during your scan.
Sometimes it is difficult to get a clear view of all of your baby at this scan. This does not mean there is anything to worry about but if this is the case, you will be offered a second scan by 23 weeks of pregnancy.
Diabetic Eye Screening
Diabetic eye screening is recommended by the NHS to check for signs of diabetic retinopathy and other eye problems caused by diabetes and monitor the health of your eyes if you are pregnant and have type 1 or type 2 diabetes but not if you develop gestational diabetes.
Diabetic retinopathy is caused when diabetes affects the small blood vessels in the retina at the back of the eye. Everyone with diabetes is offered eye screening but screening is very important when you are pregnant because the risk of serious eye problems is greater.
This test is strongly recommended if you already had diabetes before getting pregnant. Eye screening is a part of managing your diabetes and diabetic retinopathy is treatable, especially if it is caught early.
People with diabetes can decide not to attend eye screening appointments. If you decide not to have the test you should notify the clinician looking after your diabetes care during pregnancy.
The screening test
You will be offered screening at, or soon after, your first antenatal clinic visit and also after 28 weeks of pregnancy. If early stages of retinopathy are found at the first screening, you will be offered another test between 16 and 20 weeks of pregnancy. If significant retinopathy is found at any screening, you will be referred to an eye specialist.
The screening test during pregnancy is the same as routine screening at all other times.
Screening staff will record your details and level of sight. They will put drops in your eyes to make your pupils larger so the retinas can be seen more clearly. They then take digital photographs of your retinas.
If the images are not clear enough you will be referred to an eye specialist for a different test.
The photograph is painless and the camera does not come into contact with the eye. The eye drops may sting for a few seconds and cause blurred vision for 2 to 6 hours after the test. You should not drive after screening as the eye drops can blur vision.
Very rarely, the drops can cause a sudden, dramatic rise in pressure within the eye. Symptoms of pressure rise include:
- pain or severe discomfort in the eye
- redness of the white of the eye
- constantly blurred sight
If you experience any of these symptoms after screening, you should return to the eye unit or go to an accident and emergency department.
Results
A letter with your results will be sent to you and your GP within 6 weeks following your screening appointment.
Possible results are:
- no retinopathy
- early signs of retinopathy
- more serious retinopathy that requires referral to a specialist
If your test shows early signs of retinopathy, your health professional will give you advice about looking after your diabetes during pregnancy. You would then be invited for additional screening tests during your pregnancy. If you are a smoker, seek help to stop or at least cut down.
If the test shows you have referable retinopathy you will receive an appointment with an eye specialist.