Screening blood tests
We offer all pregnant people blood tests in the early stages of pregnancy to check for a number of problems. We recommend these blood tests are taken before 09 weeks and 6 days of pregnancy. Your haemoglobin is checked for signs of anaemia (low iron levels) and your blood group and Rhesus factor. We would also recommend screening for the following:
- Infectious diseases including Hepatitis B, HIV and syphilis as these infections can cause harm to you or your baby without treatment. If an infection is found, you will be offered specialist care to ensure you and your baby has the correct support and treatment.
- Sickle Cell and Thalassaemia: these are inherited disorders of the red blood cells. Anyone can carry a gene for one of these conditions but they are more common in people whose ancestors or blood relatives come from certain parts of the world. If your family origin is one from a high risk area you will be offered haemoglobinopathy screening. If you are found to carry an unusual haemoglobin gene we will discuss this with you, and will offer your baby’s biological father the same test to see if he carries a similar gene.
First and Second trimester scans
While we know that your scans are such a special opportunity to enjoy seeing your baby moving and growing inside your body, it is important that you also understand that they are also screening tests that you are consenting to on attendance. We love sharing these special moments with you, and are also looking to ensure you and your baby are safe and well.
- Nuchal scan
- Your first scan, the early pregnancy scan or nuchal scan, will be between 11 +2 and 14 +1 weeks of pregnancy and is the first opportunity to see your baby’s heart beating. At this scan we will confirm the number of babies and the estimated due date of your baby(ies) birth.
- Importantly, this scan is also a screening test for Trisomy 21, 18 and 13 – Down’s syndrome, Edward’s syndrome and Patau’s syndrome. Croydon Maternity Services offers the combined screening tests between 11 +2 weeks up to 14+1 weeks of pregnancy. It is called a combined test because your risk is calculated using signs tested in the scan, combined with a blood test. There are two parts to this test. The scan which takes measurements form your baby and a blood test after the scan. Both elements must be completed for a screening result to be calculated. The results of this screening test will give you a risk factor and are not diagnostic.
- Low chance result are normally sent via post within two weeks.
- If you receive a “Increased chance” result, you will contacted within 3 working days and offered further testing tests (The non-invasive prenatal testing (NIPT) or diagnostic/invasive testing ) to provide a definite result about your baby’s chromosomes. For more information and support for “Increased chance” results, see: Screening tests for you and your baby (STFYAYB) - GOV.UK, the arc website, down-syndrome.org,uk and the soft website.
- If you are unable to have a test before 14 +1 weeks pregnancy, you will be offered quadruple or quad test as an alternative to the combined test between 14+2 weeks and 20+0 weeks.
- Anomaly scan
- At around 20 weeks pregnancy you will have a second routine screening scan. This scan allows us to assess the baby’s physical development where we will specifically look at their heart structures; their brain; their spine; their stomach; kidneys; bladder and bones.
- We are also looking at your baby’s placenta, its location, size and position. In some personalised care plans we will also be looking at your placenta’s blood flow
- Additional scans
- All women are offer the two routine Nuchal and Anomaly scans.
- Some women may require additional scans, for example women expecting twins, triplets, who have diabetes, smoke, are obese or very underweight.
- Your midwife will advise you of your personalised care plan to include your scans when you meet at your first appointment. Changes during your pregnancy may mean that this personalised care plan is adjusted including a need for additional scans.
- Additional scans will continue to measure baby(ies) growth and physical development as well as assessing your placental function.
NIPT tests
The non-invasive prenatal testing (NIPT) is available privately or as part of the NHS pathway for birthing people with an increased chance combined or quadruple screening result at Croydon University Hospital . Those who have had a previously affected pregnant by a chromosomal condition also be offered NIPT.
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- The SAFE test evaluates the chance of chromosomal condition in a pregnancy. It is a blood test available from 10 weeks of pregnancy with a greater than 99% detection rate of Trisomy 21 (Down’s syndrome), Trisomy 18 (Edwards’ Syndrome) and Trisomy 13 (Patau’s Syndrome).
- A blood sample is taken from mum in the antenatal screening department at Croydon University Hospital . The sample is then sent to St George’s Hospital and the result is received on the online portal within 7 working days.
- The cost of the test is £350. Please note, payment can only be made by card.
- For up to date information on NIPT please go to www.theSAFEtest.co.uk.
- You can also visit the St George’s Hospital website for more information about the SAFE test.
- To book a private NIPT at Croydon University Hospital please call the antenatal screening team on 02084013000 ex 4131/4004 or email ch-tr.antenatalscreening@nhs.net
Please note: We do not screen for gender when doing the NIPT test.
Diagnostic testing
Diagnostic tests for fetal genetics (also known as invasive tests) are tests that will provide you with definite information about your baby’s chromosomes and confirm whether or not your baby has a chromosomal abnormality. All pregnant people who are assessed with a Increased likelihood or chance result from their combined or quadruple screening test will be offered a diagnostic test. Those who have had a previously affected pregnant by a chromosomal problem or have a history of an inherited condition will also be offered a diagnostic test.
- It is important to know that a diagnostic test carries a risk of miscarriage of 1 in 100, so you need to carefully consider if you would like to have the test or not.
- All pregnant people who accept a diagnostic test will be referred to our tertiary centre at St George’s Hospital Fetal Medicine Unit. For more information, please click here.
- Most babies, even those with an increased risk following antenatal screening will have normal chromosomes. For those cases where we detect an actual problem a member of the antenatal screening team will be in touch and will tell you what the problem and is and how it may affect your baby. You will be invited to meet with a member of the screening team and a fetal medicine consultant so we can discuss what options are available to you.
- For more information and support see: Screening tests for you and your baby (STFYAYB) - GOV.UK, the arc website, down-syndrome.org,uk and the soft website.
Newborn Screening
Newborn Infant Physical examination
Within 72 hours of giving birth, you will be offered a top-to-toe physical examination for your baby. This will include 4 specific screening tests. The tests check whether your baby has a suspected problem with their eyes, heart, hips and, in boys, their testicles. If a problem is suspected, babies benefit from early investigation and possible treatment.
The screening tests are carried out again when your baby is between 6 and 8 weeks of age, usually at your GP practice. This is because some conditions do not develop or cannot be identified until then.
Newborn Hearing screening
The newborn hearing screening test will be offered to your baby either in hospital before discharge, or when you are at home. Alternatively, you will be invited to attend a clinic appointment. Ideally, the screening test should be done in the first 4 weeks, but it can be done at any time up to 3 months of age.
Newborn Blood Spot Screening
When your baby is five days old they will be offered a screening test called the Newborn blood Spot (NBS). This is usually performed in a postnatal clinic, alongside your babies weight and full postnatal check. The NBS screening programme enables early identification, referral and treatment of babies with 9 rare but serious conditions. These are:
The last six conditions are inherited metabolic diseases (IMDs).
Screening for Hereditary Tyrosinaemia Type 1 (HT1) as an additional condition within the NHS Newborn Blood Spot Screening Programme, is expected to start in September 2025.
Each laboratory will test 2000 anonymised residual NBS samples (no more than 14 days old) to validate the testing process for HT1 screening before July.
NHS England are offering screening for severe combined immunodeficiency (SCID) SCID screening: helping you decide if you want this for your baby - GOV.UK as part of an evaluative roll out across England to see how it could best be introduced across England. Croydon University hospital is one and that’s why will be offered this test.
It is important to know that: after screening, blood spot cards are stored for at least 5 years and may be used:
- To check the result or for other tests recommended by your doctor (if the results could affect the health of your baby, you will be contacted)
- To help improve the screening programme or upgrade the existing testing methods for conditions already approved for screening in England (if the results could affect the health of your baby, you will be contacted)
- For research to help improve the health of babies and their families in the UK (this will not identify your baby and you will not be contacted)
In addition, there is a small chance that researchers may want to invite you or your child to take part in information gathering linked to the newborn blood spot screening programme. Researchers undertaking any additional studies would explain what is being done and you would then be asked if you wish to take part in that study. Please let your midwife know if you do not want to be contacted to discuss taking part in any additional information gathering.
All use of the blood spots is governed by the code of practice. Any research will have been approved by an independent research ethics committee.
For more information see this online leaflet Blood spot - GOV.UK, or speak to your Healthcare professional.
