Screening tests during pregnancy

We routinely offer all women blood tests in the early stages of pregnancy to check for a number of problems. We recommend these tests are taken before 9 weeks of pregnancy. For women booking later than this we recommend the tests are taken as soon as possible. In addition to checking your haemoglobin for signs of anaemia (low iron level), your blood group and rhesus factor, we also recommend screening for the following:

Screening Sickle Cell and Thalassaemia

Sickle Cell and Thalassaemia 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. Therefore we routinely ask all women where your family and your baby’s father’s family originate from to see if you are more likely to be at risk of carrying a gene for one of these conditions. This helps our laboratory interpret your blood test results too. If you are found to carry an unusual haemoglobin gene then we will discuss this with you and recommend testing your baby’s father to see if he also carries a similar gene.

More information can be found from the Sickle Cell Society and the Thalassaemia Society.

Screening for Infections 

We offer all women a screening test to identify hepatitis B, HIV and syphilis infection. All these infections can cause serious harm to your baby, but without a test you might not know that you are infected. If you do have an infection, you can receive the right care to reduce the risk of passing the infection on to your baby. We can also refer you to a specialist to ensure you too have the best treatment to optimise your own health.

For specialist advice around HIV, Hepatitis B and syphilis please contact our Specialist Health Adviser on: 07919 627603

Rubella

From the 1 April 2016 screening for rubella susceptibility in pregnancy ceased in the UK.  This national decision was made because:

• Rubella infection in the UK is at a level defined as eliminated by the World Health Organisation
• Screening for rubella susceptibility does not give any protection to the unborn baby in the current pregnancy
• The test may offer false reassurance to women that they are not susceptible to rubella infection
• Stopping antenatal screening is unlikely to result in increased rates of congenital rubella

If you booked in your pregnancy prior to 1 April 2016 you will have been offered rubella antibody screening. If you accepted this and were found to have low levels of antibody, we continue to offer the MMR vaccine after you have given birth. The first dose is usually given before you leave hospital (if you had a hospital birth) and the second dose should be given 4 weeks later by your GP.

All pregnant women booking before 20 weeks of pregnancy are offered screening tests to assess the chance of there being a problem [or anomaly] in their baby. If a problem is suspected we may offer a diagnostic test. There are important differences between screening tests and diagnostic tests which are explained below.

It is always your choice whether to have these tests or not. Remember that most babies develop normally and are healthy at birth. Your midwife or doctor will give you more information about these tests and discuss what the results may mean for you.

What are screening tests?

A screening test can find out if your baby is at high or low chance of having a health problem.

If your screening result is high chance, you will be offered a diagnostic test.

Screening tests are not perfect. Some people will be told that their baby has a high chance of having a problem when in fact they are unaffected. Also, a few people will be told that their baby has a low chance when in fact they do have a problem.

Before you make any decisions on which antenatal screening tests to accept, it is important that you and your partner think about the implications. You may find yourselves going through unnecessary worry. In the worst case, you may find you are asked to make a decision about whether or not to continue your pregnancy.

What are diagnostic tests?

A diagnostic test can tell you for sure if your baby has a problem, but these tests do not detect all chromosome and genetic problems.

Screening for chromosomal and structural problems in pregnancy

Ultrasound scans:

A pregnancy scan or ultrasound scan uses high-frequency sound waves to create a moving image of your baby. You will be able to see the image on a screen.  In most cases we are able to print out a photo for you to take away but please note we do make a charge of £5 for pictures to cover printing costs.

Most women are offered two ultrasound scans during pregnancy:

1. Dating Scan

Usually offered at around 10 to 14 weeks, this is a quick scan taking only about 15 minutes.

The purpose of this scan is to measure the size of your baby and accurately confirm the due date. It can also detect twins or more!

Unfortunately we sometimes detect a miscarriage at this scan, even though there may have been no signs beforehand.

We occasionally detect major anomalies (problems) at this scan too. If we do detect a problem we will refer you to a specialist midwife or doctor.

Many women choose to have a screening test to assess the likelihood of their baby having one of the following chromosome conditions: Down’s, Edwards’ and Patau’s syndromes. The dating scan is an essential part of such tests.  

2. Anomaly Scan

We offer an anomaly (abnormality) scan at around 20 weeks of pregnancy (between 20 weeks + 0 days and 20 weeks + 6 days is the ideal time).

This will provide a detailed examination to check the baby is developing normally. We also check your baby’s growth, the position of the placenta and the amount of fluid around the baby.

If the scan shows a possible problem, you will be referred to a specialist to confirm findings and where necessary discuss the options available to you. It is important to remember that not all anomalies will be detected on ultrasound scan.

Screening tests for Down’s, Edwards’ and Patau’s syndromes

Down’s, Edwards’ and Patau’s syndromes are chromosome conditions.

• Down’s syndrome is also known as trisomy 21
• Edwards’ syndrome is also known as trisomy 18
• Patau’s syndrome is also known as trisomy 13

Anyone can have a baby with one of these conditions because in most cases they are not inherited.

Combined screening test

We offer the combined screening test between 11 weeks and 2 days up until 14 weeks and 1 day of pregnancy. This test involves an extra measurement of the fluid on your baby’s neck (known as the nuchal translucency or NT) at the dating scan. We also take a blood test from you and record your weight immediately after the scan.

You will be given choice about which conditions you are screened for. You will be able to choose to have screening for:

• All three conditions: Down’s, Edwards’ and Patau’s syndromes
• Down’s syndrome alone
• Edwards’ and Patau’s syndromes alone
• None of the conditions

Quadruple or quad test

This screening test is only available if your pregnancy is too advanced for the combined screening test. It requires a blood test to be taken from you anytime from 14 weeks and 2 days up until to 20 weeks. This test will only screen for Down’s syndrome.

After 20 weeks of pregnancy your options for screening are limited and you would need to discuss this further with a specialist midwife or consultant.

Diagnostic (invasive) tests in pregnancy:

These tests give definite information about your baby’s chromosomes and confirm whether or not your baby has Down’s, Edwards’ or Patau’s syndrome. They may occasionally detect some other chromosome anomalies too but these tests can’t rule out all problems.

All women assessed as being at a higher chance of having a baby with Down’s syndrome after either the combined screening test or the quadruple screening test will be offered a diagnostic test.

Other women too may be offered a diagnostic test for example if they have previously had a pregnancy affected by a chromosome problem or there is a history of a known inherited condition.

Whilst most women are not routinely offered a diagnostic test, anyone can discuss these tests with one of our specialist screening midwives.

It is important to know that around 1 in a hundred (1%) of women who have a diagnostic test will miscarry. Therefore you should think carefully about why you would want to know whether your baby has a chromosome problem such as Down’s syndrome and consider the risk of miscarriage before deciding whether to have the test.

There are two different diagnostic tests:

• Chorionic Villus Sampling (CVS)
• Amniocentesis

To find out more information about these tests please speak with your midwife or doctor. We also produce a detailed leaflet explaining these tests and possible results in more detail.

Remember no test or scan can rule out all problems in your baby. It is often not always possible to detect rare chromosome problems and genetic disorders even with a CVS or amniocentesis test. If you have any questions or concerns about any aspect of screening and diagnostic testing then please speak to one of our specialist screening midwives.

What happens if a problem is diagnosed?

Most babies, even those with an increased chance result after a screening test, will have normal chromosomes. In a few cases we will confirm a problem, either on scan or by invasive test. In these cases we will tell you what the problem is and how this could affect your baby.

We will arrange specialist follow up at the hospital and discuss the options available to you. The specialist midwives for antenatal screening are available for further information and support at this time.

You can also contact ARC – Antenatal Results and Choices, who are a national organisation providing support and information about all aspects of screening and diagnostic tests for fetal anomalies during pregnancy and beyond. They are able to support families after a diagnosis of an anomaly and support around making difficult decisions around continuing or ending the pregnancy.

You might also want to read about other people’s stories and experiences at Health Talk Online.

Further information:

NHS England: Screening tests for you and your baby (available in a range of languages and in Easy Read)

NHS Choices: Screening for Down’s, Edwards’ and Patau’s syndromes

NHS Choices: Anomaly scan at 18-21 weeks pregnant

BSUH: Combined screening in pregnancy

BSUH: CVS and Amniocentesis

ARC – Antenatal Results and Choices

Health Talk Online – read about other people’s stories and experiences

Towards the end of your pregnancy your midwife will talk to you about the screening tests we will offer for your baby after birth.

Newborn Physical Examination Screening

We offer four specific screening tests within 72 hours of birth to check whether your baby has a problem with their eyes, heart, hips or, if they have them, their testes which may benefit from early investigation and possibly treatment. This examination is part of the Newborn and Infant Physical Examination (NIPE) screening programme.

Newborn Hearing Screening

All babies are offered a hearing screening test before leaving hospital or in a clinic setting if your baby was born at home.  We offer screening for hearing loss very early so that support and advice can be offered right from the start of your baby’s life. Early diagnosis can give babies with hearing loss a better chance of developing speech and language skills.  For more information take a look at our Trust leaflet.

Newborn Blood Spot Screening

We offer your baby screening for 9 rare but serious health conditions. Early diagnosis and treatment for these conditions can improve your baby’s health and in some cases prevent severe disability, brain damage and death. We screen babies on day 5 of life by pricking their heel and collecting drops of blood on a sample card. The conditions we screen for are:

Sickle cell disease, cystic fibrosis, congenital hypothyroidism and 6 different inherited metabolic diseases.