Blood Test for Pregnancy Check

Why need Blood Test for Pregnancy Check

You need to carry out several kinds of tests during pregnancy. The tests would require different types of samples which would include those that require blood samples.


During pregnancy, you would need to carry out several kinds of tests. The tests would require different types of samples which would include those that require blood samples. The routine investigations carried out on your blood sample would be used to check your blood group, whether or not you have any infections or diseases, and several other things. You also need these routine blood tests for pregnancy to know how healthy your baby is.

This article aims to answer all your questions regarding the blood tests you need during pregnancy.

What blood tests will I carry out during pregnancy?

During your appointment with your health care provider, you would be required to carry out the following tests.

  • Blood group

A blood test to know your blood group is necessary because you may need a transfusion during pregnancy or while giving birth. The most common blood group is O while, blood groups A, B, and AB are less common.

  • Rhesus (RH) factor

Being rhesus positive means that you have a particular protein on the surface of your red blood cells but, if you are rhesus negative, it means that the surface protein is not on your red blood cells.

If you are rhesus negative (RhD negative) and your baby’s father is rhesus positive (RhD positive), your baby is likely to be RhD positive. When your blood mixes with that of your unborn baby, your body reacts to it by producing antibodies since the blood type is different from yours.

If this is your first pregnancy, the reaction may not affect the pregnancy but, subsequently, the antibodies produced will attack the red blood cells of any other RhD positive babies you would have. This could be dangerous and requires you to be on some medications to prevent the loss of the baby before birth.

If you have injections of immunoglobulin at the 28th and 34th week of your pregnancy, it will prevent the loss of your baby by stopping the production of the antibodies.

You can also carry out non-invasive prenatal testing (NIPT) to identify if you and your baby have compatible rhesus factors. If the NIPT shows that you and your baby are incompatible, you would need the immunoglobulin injections.

  • Haemoglobin levels

A blood test for your haemoglobin level would tell you whether or not your haemoglobin levels are low. A low haemoglobin level is an indication of iron-deficiency anaemia which is not good for you and your baby because your body needs iron to produce haemoglobin for your red blood cells to carry oxygen around your body.

If you have iron-deficiency anaemia, your doctor would tell you the best sources of iron and probably prescribe iron tablets for you.

You would need to check your haemoglobin levels at 28 weeks but, if you are carrying two or more babies, you may need an extra blood test between 20 – 24 weeks in addition to the standard 28-week check.

  • Hepatitis B virus

You will need a blood test to check if you are infected with the hepatitis B virus. If you are infected, you are likely to transfer the virus to your baby before or during childbirth. In this case, your baby would need to be protected by getting a series of injections consisting of vaccines and antibodies from when the baby is born.

  • Syphilis

If you have syphilis and it is not treated during pregnancy, it could lead to your baby having some abnormalities. It can also cause a miscarriage or stillbirth.

Treatment for syphilis during pregnancy consists of a course of antibiotics. These antibiotics are safe for your baby, but, your baby would need an examination, blood test, and possibly antibiotics after birth.

  • HIV/AIDS

All pregnant women are required to have a blood test for HIV/AIDS. This may feel uncomfortable, but, knowing your status is necessary and, if you are positive, you would be offered medications to help reduce the chances of passing the virus down to your baby.

What other blood-screening tests would I need?

You may need a screening test to check the possibility of your baby having a genetic condition like Down’s syndrome.

Your doctor will require you to have the combined screening at about 14 weeks which is around the end of your first trimester. The combined screening consists of blood tests and a nuchal translucency scan.

The combined screening is more accurate than the quadruple blood test, which is done during the late stage of pregnancy if you missed out on the combined test. If the result of your combined screening shows that your baby has a high chance of a genetic condition, you would be offered non-invasive prenatal testing (NIPT). This is more accurate than the combined screening.

Screening tests do not tell you if your baby has a condition. It only gives you an idea of the likelihood. If the screening shows that your baby is likely to have a genetic condition, you would need a diagnostic test such as CVS or amniocentesis.

Will I be tested for blood-cell disorders?

You may need to test for thalassaemia and/or sickle cell depending on how many people in your area are thought to be at risk of these disorders.

If you are in an area where many people do not have sickle cell disease, you may need to fill out a questionnaire about your family origins to help your doctor decide if you need to test for sickle-cell disease.

Do I have to get all these blood tests done during pregnancy?

The blood tests are optional, but, your doctor would explain the importance of all these blood tests to you.

You may not want to want to carry out these blood test for fear of what the results would show but bear in mind that the tests would help you and your doctor know your wellbeing and that of your baby.

Can I ask for extra blood tests?

Some blood tests are not always required, but, you can ask to get them done. You can carry out a test for toxoplasmosis which is spread through cat faeces, soil and undercooked meal. You can also request to carry out a hepatitis C test if you have a high risk of contracting the virus.

If you need a private blood test for pregnancy, you can contact your nearest medical centre in London.

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