Antenatal Screens and Tests of Foetal Health

It’s perfectly natural to have concerns about the health and safety of an unborn baby during a pregnancy, and fortunately there are ways to test the health of a developing foetus during the earlier stages of a pregnancy. The subject of genetic testing to this end remains controversial in some circles, but the option is available on the NHS and in private care at present. This article aims to provide some general information about the kind of screening and testing that can be done at the beginning of a pregnancy to determine the future health of an unborn baby.

How common are abnormalities after/during a pregnancy?

While there are many steps you can take to make your pregnancy as healthy as possible, there are always factors that you can’t account for and many abnormalities can’t be avoided as they are a consequence of natural biological error. About 3% of all children born in the UK suffer from some form of disorder that causes about two thirds of that number to suffer a serious disability.

These figures are quite small, and in most cases the genetic nature of abnormalities means that if there is a chance a baby can be born with a birth defect, there will probably be a background history of familial disease. That being said, there is always a small chance of spontaneous genetic changes that can cause a birth defect without a previous history of familial disease, however these cases are few and far between.

Other birth defects include structural abnormalities that can also be tested for. A prominent example of Spinal Bifida, a condition which results in a serious disability. 

Testing for genetic issues and other abnormalities during a pregnancy

An important part of your initial antenatal appointments will be a series of questions your midwife or doctor will ask you to explore your family’s health history. These questions give an understanding of any familial genetic diseases which can potentially be passed on to your newborn.

If you do have a family history of genetic disease that can result in a serious disability, then chances are your midwife or doctor will talk to you about pursuing a test that can determine whether or not the developing foetus carries disease causing genes. These tests are only performed with your permission of course, and your doctor will probably talk through the details with you before you need to make a decision.

What kind of tests are there?

There is a distinct difference between screening for genetic diseases prior to a pregnancy and during a pregnancy. Such tests, when conducted before a pregnancy, utilise samples taken from parents and gives an idea of the likelihood that a child might inherit a particular genetic illness. Testing performed during a pregnancy however, makes use of samples taken directly from a developing foetus, which gives an accurate indication of whether or not an unborn baby carries defective genes.

Not every possible disease can be tested for, but at present major conditions like cystic fibrosis and Down’s Syndrome can be determined with a high degree of accuracy. Amniocintesis and chorionic villus sampling are the two main tests used to detect genetic abnormalities in developing foetus.

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