Routine Screening Tests in Pregnancy

Most people believe that blood tests are a standard part of pregnancy care. Do you know what they are for? Are you aware that all tests are optional?

The team at Private Midwives are committed to giving you information, so that you can make informed choices about what is right for you and your baby. Any suggestion we make is for you to consider. We offer a number of blood tests at the start of pregnancy in line with what the NHS and HSE recommends, but you are under no obligation to agree to have them.

So, what are the tests we offer and why might you want them?

 

Infectious Diseases

We offer screening for are syphilis, HIV and hepatitis B. Each year testing in pregnancy identifies women not previously aware of  infection who have one of these conditions.  All of these conditions can be treated/managed to reduce long-term health issues for mum and baby. The sooner they are found, the less the risk, so we suggest testing as soon as you start your care with us.

You can be infected with syphilis for many years without realising. It is passed on through sexual contact and can infect a baby during pregnancy untreated it can lead to major brain and nerve damage. A baby infected during pregnancy has a high chance of miscarriage or stillbirth. Quick and effective treatment is available which cures syphilis. Many people think that syphilis “no longer happens”, in fact numbers of cases have risen in recent years in the UK and are now greater than at any time since World War II. If you have had syphilis is the past and been effectively treated, that will affect the result, so please do tell your midwife if this applies to you. Please don’t be embarrassed. We want to know how to interpret the result appropriately and to be sure that you have had the best treatment, and to be sure that you have not been reinfected.

HIV is a viral infection, passed on by intimate contact. It can be passed to baby during pregnancy, at birth or through breastfeeding if the levels of virus in the mother’s body are high. This can usually be managed very effectively with drugs and good management of the birth, reducing the chance of the baby being infected from around 25% to about 0.5%.

Hepatitis B is a type of hepatitis (liver infection and inflammation). It is a viral infection which can cause both short and long-term issues because it remains in your body. Long term issues can include liver cancer. It is passed through blood contact, for example needle sharing (tattoos, drugs etc), through sex and, very commonly, during pregnancy and at birth. All pregnant women with hepatitis B are advised to be seen by a hepatitis specialist to ensure that the chance of spreading the infection to the baby and their close contacts is minimised. Very effective immunisation is available to protect against hepatitis B. This can be given to household contacts and your baby can have the first dose very quickly after birth

 

Blood group and rhesus factor

There are several types of blood (known as your blood group) just as there are different hair types and eye colour. It only matters what blood group you have if you need a blood transfusion (or are generous and donate your blood) and when you are pregnant.

Blood groups are known by the letters A, B, AB and O. You will also be “rhesus positive” (written as Rh+) or rhesus negative (Rh-). So, your full “grouping” may be for example AB- or O+.

You get your blood group from one of your parents. An issue can arise if the mother is rhesus negative and the baby is rhesus positive (inherited from dad). In this situation, the mother’s body can make “antibodies” which can have a negative effect on future pregnancies if not treated. In this situation you will be offered a product called “Anti-D” which can stop your body making antibodies and protect any future pregnancies and babies that you may have.

There are other red cell antibodies that can be identified, during this testing. Some are only relevant if you need a blood transfusion, others can affect baby and so need special monitoring during the pregnancy. Most usual, however, is for the report to say, “no antibodies detected”. This is specifically in reference to  “red cell antibodies”. It is not a test for antibodies to infections, including Covid19.

 

Haemoglobin type

Haemoglobin is the part of your blood that carries oxygen around the body. This is different from your blood group. Like your blood group you inherit the type of haemoglobin you have from one of your parents, but in this case, you get part from each of them. There are some combinations which can cause health problems, such as beta thalassaemia and sickle cell disease. These are known as haemoglobinopathies –  haemoglobin types that can cause health issues.

If you are found to have a haemoglobin type which could create a relevant combination, it will be suggested that your partner is also tested. This allows us to consider possible combinations and whether there is any need for concern. If you have used a donor egg or donor sperm, it is the donor’s haemoglobin type which is important in this context.  The clinic you used may be able to tell you the haemoglobin type of the donor, but not all clinics test for this.

If one of the biological parents has a common type of haemoglobin known as AA, testing of the other biological parent is not needed. Therefore, if you used a donor egg and your partner’s sperm , we would suggest testing him.

 

Full Blood Count

A Full Blood Count (or FBC) checks your blood for iron levels and platelet levels.

Your iron levels are always important and are tested via your haemoglobin count, many people suffer from anaemia and this should be treated with iron supplementation. In pregnancy it is even more important as your baby needs lots of iron to grow and your levels will naturally fall during your pregnancy. By checking your haemoglobin we can predict whether your levels are likely to fall to anaemic levels and make suggestions around your diet or supplementations which should help you feel better and make sure that both you and your baby are well. This test is often offered at your booking visit and again at around 28 weeks and/or if you are feeling very tired, short of breath or dizzy. If your iron count is particularly low and is not improving we may suggest other tests to check your Vitamin B12 levels as low Vitamin B12 may be the cause of your anaemia.

 

Your platelet count tells us about your body’s ability to clot your blood. Occasionally people either have or develop a condition called thrombocytopenia which may have implications for your birth choices as it can cause some post-partum bleeding.

 

Feel Free to Ask Questions

It’s important that you feel safe enough with your healthcare team to ask questions about any tests that are requested and to ask what impact they may have on your care before you agree to them. This is called Informed Consent and is one of our core philosophies as midwives. So do feel free to ask us anything and remember that you can consent or decline, and you can also change your mind! You are at the centre of your pregnancy journey, and we are delighted to support you along the way.

Find out more about screening tests here.