Always ask the reason for tests – they may be routine and straightforward to the health professionals carrying them out, but not to you. All the tests are optional and your midwife will explain to you what they are for. You can then decide to go ahead with them, or not, as you wish.
You will be offered several tests and checks as an important part of your care during pregnancy. These tests are intended to help protect you and your baby’s health. It’s up to you whether you have the tests. The test results are confidential and only you and the healthcare professionals closely involved with your care will be told the results. Nobody else will be told the results without your permission. Your midwife will be happy to
discuss tests currently offered in your area with you.
Routine blood tests
You will be offered at least one blood test in pregnancy, usually taken at your first antenatal appointment, although different regions in Scotland may do this at different times. A blood test just means taking a little blood from a vein in your arm. The blood is drawn up into a syringe or vacuum tube. A blood test shouldn’t be painful but may be uncomfortable, and there may be slight bruising for a day or so afterwards.
The sample will be put in separate test tubes so that a number of different tests can be carried out. The tests are intended to make sure you and your baby are healthy, but it’s up to you whether you have them or not. You will be asked to sign a consent form.
Blood tests can include:
- full blood count: the full blood count (FBC) is a good all-round measure of health. If it is low it indicates you could be anaemic
- blood group: this identifies your blood group (A, B, O or AB). It can also identify whether there are any blood group antibodies in your blood
- rhesus positive or negative: if you are rhesus positive, no further action will be taken. If you are rhesus negative, you will be offered injections called anti-D, which help prevent a serious illness for any future babies you may have. One in six women are rhesus negative
- syphilis: this is a sexually transmitted Infection (STI). It is rare but, if undetected, it can seriously damage your health and that of your baby by causing developmental difficulties. Effective treatment (a course of antibiotics) is available
- hepatitis B: this is a viral infection that causes liver disease and can be passed from mother to baby during or just after delivery. If you test positive, your baby will receive a complete course of a very effective vaccine and possibly injections of antibodies called immunoglobulin immediately after the birth
- HIV: the Human Immunodeficiency Virus (HIV) is the virus that causes Acquired Immunodeficiency Syndrome (AIDS). Infected pregnant women can pass HIV to their babies during pregnancy, childbirth and also through breastfeeding. HIV attacks the body’s immune system and destroys the body’s defences to infection. It can take years for HIV to do enough damage for you to become ill, so usually the only way to tell if you are infected is to take a test. If your HIV result is positive, advice and treatment under the guidance of specialists will be offered. Interventions include treatment with special drugs and advice about the best type of delivery and the best method of feeding your baby to reduce the chance of her also getting the infection. For more information about HIV and AIDS, see Further help.
- Haemoglobinopathies These disorders affect the part of the blood that carries oxygen around the body, called haemoglobin. Some conditions are more serious than others. These are inherited disorders. This means that parents can pass these haemoglobinopathy genes on to their children even though they look and feel perfectly well. They are 'carriers' - but they do not have a disorder themselves. Children can inherit carrier status from a carrier parent. But if both parents are carriers, there's a chance that their children will have one of the disorders. Testing allows parents to find out if they are carriers and if their baby has a chance of inheriting a disorder so that they can make decisions about the pregnancy and have the right support after the birth.
You will be told when you can expect your results at the time they are arranged. If there is a problem or anything you should know, you will be contacted as quickly as possible. If you have any questions or concerns about these tests, please ask at your next clinic visit or contact your midwife.
All the checks you'll be offered are for your health and the health of your baby.
Your blood pressure is checked at most appointments. It is normally taken in early pregnancy to get a baseline and later to make sure you have no signs of pre-eclampsia or pregnancy-induced hypertension.
The midwife wraps a fabric band around your arm and inflates it with a small pump. The band is linked to a blood pressure measure. As it deflates, the midwife uses a stethoscope to listen to changes in your pulse.
A high reading may give cause for concern, so the test may be done again, 10 or 20 minutes later, to make doubly sure.
Carbon Monoxide (CO)
Carbon monoxide is a poisonous gas which you can't see or smell and is dangerous to you and your baby. CO monitors are used to establish how much carbon monoxide is in your body and is measured through a quick and simple breath test.
The results are available immediately. If you are a smoker, or are exposed to high levels of second-hand smoke, your CO level will be high. Your midwife will discuss this with you and refer you for support from the stop smoking services.
Your urine will be tested for protein and sugar. A special strip is dipped into a sample which you either bring with you or produce at the appointment. Some women develop a particular sort of diabetes that occurs in pregnancy – gestational diabetes. This may show as sugar in the urine. Protein may indicate pre-eclampsia. Infections of the kidney and bladder may show up here too.
Your abdomen (tummy) will be examined at each visit. By moving her hands around the outside of your abdomen, the midwife feels the way your baby is lying, and her size and the height of your uterus.
Screening and diagnostic tests for Down’s syndrome
Most babies are born perfectly healthy, but a few are born with conditions such as Down’s syndrome or other chromosomal abnormalities. There are tests available during pregnancy that can help to detect these rare conditions.
You can choose whether or not to have these tests, and you may want to discuss this with your midwife. In most cases further tests show your baby is healthy. If not, you will be offered counseling to help you decide what to do.
There are two types of test: screening, which is offered to everyone, and is intended to show whether there is a low chance or a high chance of your baby having a condition such as Down’s syndrome; and diagnostic, which means further tests that may be carried out depending on the results of the screening test. About one in ten women will be offered second follow-up tests such as amniocentesis or ultrasound. While screening offers a good way to assess how likely it is that your baby has one of these conditions, it is not perfect and will not detect all problems.
The screening test involves taking a blood sample from your arm. It cannot determine if the baby has a chromosomal disorder, but can indicate whether you have a low or high chance of your baby having Down’s syndrome. The test will detect about two out of three Down’s syndrome pregnancies.
Ultrasound scanning is used with chorionic villus sampling (CVS) and amniocentesis, so that the doctor can see the exact position of the baby and the placenta. Scans are also sometimes used to detect some abnormalities.
The CVS check for chromosomal abnormalities, mainly Down’s syndrome, and amniocentesis are tests which are usually only offered to women who have a higher chance of having a baby with a disability. An older mother, for example, is more likely to have a baby with Down’s syndrome. A test may also be offered to a mother who has had a previous pregnancy affected by one of these abnormalities. There is a very small (about 2%) risk of miscarriage with these tests.
CVS can be performed from 11 weeks of pregnancy. A fine tube goes into the uterus, usually through the abdomen, and a syringe is used to remove a sample of the chorionic villus, the tissue forming the placenta. For every 100 women who have CVS, one or two will have a miscarriage. Results may be available after 48 hours, but a more detailed examination can take up to 14 days. The main advantage of CVS over aminocentesis is that CVS can be done earlier. A CVS may not be offered locally, so you may be referred to a centre outside your area.
Amniocentesis is done after 15 weeks. A needle is inserted into the uterus through the abdomen and a sample of amniotic fluid is taken with a syringe. For every 100 women who have amniocentesis one will miscarry. Results will be available within 48 hours but the outcome of a detailed examination can take up to 21 days.
Ask your midwife about what tests are available, how reliable they are, and what is involved.
Down’s syndrome describes people with an extra chromosome. Children with Down’s syndrome will have learning difficulties and need help with their education. Although many have a healthy life, some have problems such as heart defects. Older mothers are more likely to have a baby with Down’s syndrome.
The risk rises from one in every 1,500 births for women aged 20 years, to one in every 900 births for women aged 30 years. It increases to one in every 100 births for women aged 40 years.
Is there a problem?
When tests show there could be a problem, you need more information and support. It’s important to know what the test result shows, whether it’s definite or not, and whether you need to make decisions about labour or birth or the future of your pregnancy. You may need time to consider your options.
Support groups can help you with these difficult decisions (see Further help) and you can ask to talk with your midwife as well as your GP. If the tests indicate a disability, you may want to talk to parents who have a child with a similar condition to find out more about it. No one should try to influence you in any way; the decisions you make based on this information have to be yours and your partner’s.