Benefits of Having Amniocentesis

An important part of modern antenatal care is the provision of tests that allow parents and their medical team to investigate the genetic health of their child. One such test, amniocentesis, looks for large scale chromosomal (defined in more detail later in this article) defects that cause lifelong debilitating disorders like Fragile X Syndrome and Down’s. The test involves the delicate extraction of a small sample of fluid surrounding an unborn child between the 15th and 20th week of a pregnancy. This sample is then studied using prenatal genetic diagnosis to determine the future health of your child.

The procedure does carry with it some small risks of infection, injury, and miscarriage, and while the technique is constantly improving and is being performed more and more often, it is still only performed when the benefits outweigh the risks. So when is it a good idea to have amniocentesis?


Should I have Amniocentesis?

The decision of whether or not to go ahead with a procedure like amniocentesis will always be your own, your doctor or midwife will only suggest that the test can be beneficial and provide you with whatever information you need to decide whether or not to go ahead with the procedure.

Amniocentesis is used primarily to look for chromosomal abnormalities. Our bodies grow and develop in the womb, and then function for the rest of our lives, on the basis of a set of instructions encoded in our genes. Genes are further arranged into 23 pairs of structures called chromosomes (46 in total in humans), which work to ensure that everything works as it should. Because of the importance of chromosomes and genes in the healthy workings of our bodies, any disruptions at this level can have life long and debilitating consequences, including, for example, trisomy 21, a condition where there is an extra 21st chromosome which results in Down’s Syndrome.

Because amniocentesis is used largely to test for these chromosomal abnormalities, you are likely to be offered the test if there are factors that increase the chances of a chromosomal abnormality in play. For example, if you have had pre-pregnancy genetic tests that showed a significant risk of your baby developing a chromosomal disorder or if you have a family history of particular genetic illnesses that puts your future children at risk.

If you are pregnant and over the age of 35 then amniocentesis might be recommended, particularly if you haven’t had an earlier screening test to work out your chances of conceiving a child with genetic instabilities. After the age of 35 the chances of a your unborn child bearing a chromosomal defect are higher, which is why your doctor is likely to suggest the test if you are pregnant for the first time after 35.

Amniocentesis is also a useful method for determining the sex of an unborn child at an earlier stage, which is particularly important if you or your partner carry a disease with a sex chromosome component. Our gender is determined by a particular pair of chromosomes called sex chromosomes, (women have two X chromosomes while men have one X and one Y chromosome). Some genetic conditions only affect offspring of a particular sex, which is why knowing the gender of your child quickly can be important in determining whether or not the child will suffer from the illness. Examples of such conditions include Duchenne Muscular Dystrophy and Haemophilia, both of which are debilitating disorders that are far more likely to affect male children.


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