Tests during pregnancy

Tests to look after you and your baby

The most important thing to remember is that around 9 out of 10 pregnancies and births are normal. The tests during pregnancy are simply there to help ensure that any problems are caught as early as possible, giving your baby and you the best care during pregnancy. Some of them might sound a bit complicated but these really are all standard routine tests:

Amniocentesis test

Usually carried out around the 15-18 week stage of pregnancy this diagnostic test looks to see whether your baby has Down’s Syndrome or other chromosomal problems. You’re more likely to be offered this test if you’re over 35, have given birth to a child with any particular conditions or if you or your partner has a family history of genetic abnormalities.

You’ll also be offered this test if you have a high risk result from blood tests or the nuchal translucency scan.

Before the test is performed, you will have an ultrasound scan to check your baby’s position and the position of the placenta. Then the skin over the abdomen is cleaned and a fine needle passed into the womb. A sample of the amniotic fluid that surrounds your baby is removed with a syringe and sent for testing. The position of the baby and the needle are monitored carefully during the scan by ultrasound.

Many mums say that the test is more uncomfortable than painful and feels similar to period pain. It takes around 25 minutes and you should have the results within a fortnight. 
It’s a good idea to take things easy for a couple of days after the test and to make sure you have help looking after any other children if you have them. 
Amniocentesis is generally fairly safe and many women find that the benefits of the test (providing a diagnosis of possible abnormalities in their baby) outweigh any danger of complications. There is some risk associated though, with one in 100 women developing complications afterwards that can result in a miscarriage – so in order to make an informed decision, it’s best that you talk it through with your midwife or doctor.

Chorionic villus sampling (CVS)

Chorionic villus sampling (CVS) is usually offered in the first trimester as an alternative to an amniocentesis test. The main difference is that it cannot detect spina bifida. The procedure is similar to the amniocentesis test, but the sample is taken from the placenta. It’s normally offered to women over 35 who havea family history of genetic diseases or who have already had another child with a problem. The test takes about half an hour to complete and is a bit more painful than an amniocentesis. It involves taking a sample of choronionic villi cells, which are found on your placenta.

Once you’ve had the test, you’ll need to take it easy for a couple of days.And as with an amniocentesis, a CVS test carries a tiny risk of miscarriage, so it’s important to discuss any questions or concerns with your midwife before you go ahead.

Glucose tolerance tests

During the second half of pregnancy you may be screened for gestational diabetes which occurs in 2 to 3 mums-to-be out of 100. Those most at risk will tend to be over 35, obese and may have had it in a previous pregnancy. It is also more common for mums to be who are Indian, Afro-Caribbean or from the Middle East. This blood test will detect whether you have gestational diabetes or not.

The test involves fasting overnight before some blood is taken. You are then given a glucose drink and after a short period of waiting, another blood sample is taken. The glucose levels in the blood are read to see how the body has dealt with this. If the blood tests show you have gestational diabetes you will be referred to a specialist for advice on your diet and the use of insulin injections.

Routine blood tests

During your pregnancy you can expect to have quite a few blood tests. There’s no need to worry, they’re all completely routine. They check:

  • Iron levels: If they’re low you may feel tired and lethargic. You can try adding more iron-rich foods to your diet such as red meat, spinach, fortified cereals, nuts and seeds to give you a boost. And if a change of diet isn’t enough to make a difference, you can be prescribed iron tablets to increase your iron levels. As your levels can change during pregnancy you’ll be tested again around the 28 week mark.
  • Your blood group and Rhesus factor: Your midwife and doctor need to know your blood group for medical records and also whetheryour blood is Rhesus positive (Rh+) or Rhesus negative (Rh-), as both blood types are incompatible. If your blood is Rh- and you’re carrying a baby who is Rh+, there is a possibility that if your blood gets mixed, your body could produce antibodies to fight the Rh+ blood cells. This could affect your baby later on in your pregnancy, or in your next pregnancy, if you have another baby. By knowing in advance which blood group you are, your doctor can minimise the chance of any potential problems happening, especially during labour when your blood and your baby’s are likely to get mixed.
  • German measles (also known as rubella): You were probably given injections as a child to immunise you against German measles.However, if blood tests reveal that you aren’t immune, you’ll know you need to avoid anyone who has the measles because it could harm your baby.
  • Other diseases: Your blood will be tested for hepatitis B and syphilis as both can be harmful to your unborn baby. You’ll also be offered a test for HIV / AIDS, it’s up to you whether you accept it. There’s no reason to worry about these tests – the results are confidential and are carried out so that your baby’s health can be taken care of.

Urine tests

Your urine will be tested routinely during pregnancy for:

  • Protein isn’t normally present in your urine. Its presence can be a sign of infection or contamination or if accompanied with other symptoms, may indicate pre-eclampsia. This is a condition that can be serious for both mums and babies. Your doctor or midwife can give you more information or you can read about pre-eclampsia here.
  • Urinary tract infections can give you problems later in pregnancy if left untreated but some don’t tend to have any symptoms. A urine test will find them and they can then be easily treated with antibiotics.
  • Glucose is not normally present in your urine, so its presence may indicate a high sugar diet or could just be that you have recently eaten sugary foods. If you repeatedly have glucose in your urine, it can be a sign of gestational diabetes which can be a problem for mum and baby, and your midwife would carry out a glucose tolerance test to check this. If you are found to have gestational diabetes you will see a specialist doctor at the hospital for extra antenatal care.

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