Pregnancy tests

Tests during pregnancy

Throughout pregnancy, you can expect regular tests to monitor the wellbeing of you and your baby. Most of these tests are routine but some extra tests may be advised if your midwife wants to keep a closer eye on developments for a particular reason.

If you’re ever unsure what a test is for or have a question about it, your midwife will be able to talk you through the details. Our team of experienced mums, pregnancy advisors and midwife has plenty of advice to offer too. Call them on 0800 996 1000 or start a Live Chat on our instant online messaging service.

Blood tests

Blood tests are taken throughout pregnancy to make sure you and your baby are healthy. They are used to check:

Your blood group and Rhesus factor: Taken for medical records during early pregnancy, it’s important to know your blood type and whether or not it’s compatible with your baby’s. Your body’s natural response to unfamiliar blood cells is to produce antibodies against them, which could affect your baby later during pregnancy or during birth. It may also affect future pregnancies. But being aware of any incompatibility will enable your healthcare professional to advise you on how to guard against problems.

Iron levels: Iron is essential for healthy blood. Too little iron in your diet can affect your energy levels and can leave you lethargic and feeling more tired than usual. Your iron levels may fluctuate during your pregnancy, so you will probably be tested during your first trimester and then again at 28 weeks. If your levels are on the low side, increasing your intake of iron-rich foods may help. Red meat, broccoli, nuts, and fortified breakfast cereals are good sources. You may be prescribed iron supplements if you need a more significant boost.

German measles (also known as rubella): This usually uncomplicated illness can have harmful effects on your baby during pregnancy. You may have been immunised as a child but this blood test will check whether you are fully immune or whether you need to purposely avoid people who may have measles.

You will also be checked for other diseases that could be harmful to your baby, such as hepatitis B and syphilis. An HIV/AIDS test is now offered as standard practice but it’s your choice whether or not to have it.

Urine tests

At most antenatal appointments with your midwife, you’ll be asked to give a urine sample. This is used to check for the following:

• Protein: Not usually present in your urine, protein can indicate an infection, contamination or the potentially serious condition, pre-eclampsia
• Glucose: A positive glucose result may be due to recently ingested sweet foods; a repeatedly positive result could be an indication of gestational diabetes. A glucose tolerance test will confirm it and if diagnosed, you’ll be referred to a specialist for advice and close monitoring
• Urinary tract infections: Not always accompanied with obvious symptoms, untreated urinary tract infections can lead to problems later in pregnancy. A simple course of antibiotics will clear them up quickly

Glucose tolerance tests

Gestational diabetes affects 2–3% of women during pregnancy. It’s more commonly found in women who are over 35, obese, or of Indian, Afro-Caribbean or Middle-Eastern origin. If you’re advised by your doctor or midwife to have this test, it is usually performed at 24 - 26 weeks. Occasionally, if you have a history of gestational diabetes , if your baby is larger than expected or if you start to produce sugar in your urine, you may be advised to have the test earlier than 24 weeks.

Taken during the second half of pregnancy, you will be asked to fast the night before and the morning of your test. After giving one sample of blood, you’ll be given a glucose drink and a short period later, another blood sample will be taken. The results will show how your body has processed the glucose.

If they indicate gestational diabetes, making a few changes to your diet is usually the first course of action. You’ll be referred to a specialist who will go through all the details and advise you about controlling your blood sugar through a well balanced diet.

Amniocentesis test

This diagnostic test is used to check for Down’s Syndrome and other chromosomal issues. Usually performed between 15 and18 weeks of pregnancy, you may be offered it if the results of your blood tests or nuchal translucency scan indicate a high risk, if there is a history of similar conditions in your family, or if you’re over 35.

The amniocentesis involves taking a sample of your amniotic fluid for testing. First, an ultrasound is used to check the position of your baby and the placenta. The sample is then taken using a fine needle inserted into your abdomen. This can cause a sensation similar to menstrual cramping. Ultrasound is used to monitor the position of your baby and the needle throughout the test, which takes around 10-15 minutes, but don't worry, the needle will only be in place for about a minute. You will usually have the results within 21 days.

You’ll need to rest for a day or two after the test so make sure you can take a couple of days off work and arrange for help looking after any other children.

Amniocentesis is a relatively safe test and although there is a one in 100 risk of complications associated with miscarriage, many women find that the benefits of knowing about possible abnormalities far outweigh the risks. Your midwife or doctor will be able to talk through the implications of the test. Or if you’d like to talk to one our experienced pregnancy advisors, you can reach them on 0800 996 1000 anytime.

Chorionic villus sampling (CVS)

Similar to the amniocentesis test, Chorionic villus sampling (CVS) takes a sample of cells from the placenta. These cells will indicate any chromosomal abnormalities, although they will not show the presence of spina bifida. This test carries a small risk of miscarriage so be sure to talk through any concerns with your midwife before choosing to have the test.

CVS is offered as an alternative to an amniocentesis test during the first trimester to women with a family history of genetic complications, a child or children with certain conditions, or those over 35.

Lasting around 10-15 minutes, with the needle being in place for 2-3 minutes, this test can be more painful than the amniocentesis and the doctor may use a local anaesthetic to numb your skin. You should rest for a couple of days afterwards.

If you have any questions or concerns about the tests you are offered during pregnancy, our team of experienced mums, pregnancy advisors and midwife are here to talk you through them. Give them a call on 0800 996 1000, or ask them online via Live Chat , our confidential messaging service available from 8am to 8pm.