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Amniocentesis meaning ‘puncture of the amnion’. It is a medical procedure performed on pregnant women. This procedure was developed by Richard Dedrick.

In this procedure, a small sample of amniotic fluid is collected from the thin-walled amniotic sac present in uterus to diagnose genetic and chromosomal defects of a foetus. Thus, this test enables parents to form an idea about the health of their baby before its birth and prepare accordingly. 

This procedure is generally recommended when either of the parents have a medical history of congenital disabilities in their family or if the mother has previously given birth to a baby (or babies) with a birth defect. 

Aside from that, it is also suggested to women who will be over 35 years of age while giving birth. It is because the risk of giving birth to children with birth defects is directly proportional to the age of a woman. Studies have shown that around the age of 35, the risk of a woman having a child with congenital disabilities is one in 200. 

The Procedure 

You learnt about what is amniocentesis in the previous section. You should also note that it is a quick and straightforward procedure with almost no risk involved, inducing only minor discomfort to the patient.

Most medical experts agree that the best time to do the process is between the 14th and 16th week or the second trimester of pregnancy. If the procedure is conducted too early, it may pose serious risks such as miscarriage. In some cases, amniocentesis is also carried out during the third trimester to know the condition of foetal lungs.

Let us now learn more about what is amniocentesis procedure. The whole process of amniocentesis has been listed below – 

  1. Before this procedure begins, the medical care provider will use an ultrasound to determine the exact location of foetus and to track its movements within uterus. The ultrasound also enables one to detect any abnormalities and amniotic fluid levels.

  2. Next, patients are prepared for the procedure. The abdomen is cleaned with an antiseptic and sterile gel to minimise the risk of any infection. 

  3. Once patients are ready, a needle is inserted through the abdomen and walls of uterus into the amniotic sac guided by ultrasound, and a small amount of amniotic fluid is collected. The needle is inserted in an area away from the location of the embryo. 

  4. The quantity of amniotic fluid collected from patients will be determined based on weeks or trimester of the pregnancy. 

  5. Once the procedure is complete, patients are advised to rest for a day and avoid any heavy lifting.

The amniotic fluid will be sent to a laboratory where it will be analysed. The free-floating foetal cells are separated and cultured. Once the cultured cells have grown (which usually takes a few weeks) the chromosomes are put under a microscope to detect any genetic abnormalities, foetal infections, biochemical and neural tube defects. 

However, this procedure also helps in determining the sex of the foetus. As a result, in some countries such as India, it is illegal to conduct this procedure. 

Advantages of Amniocentesis

Some benefits of this procedure are as follows – 

  • This procedure has been successful in detecting down syndrome.

  • It also aids in detecting genetic disorders such as Tay-Sachs disease, sickle cell anaemia, haemophilia and the like.


Now that you know what is amniocentesis, you should know that this procedure is very safe and involves nominal risks. Moreover, there are no long-term side effects to this procedure. Short term side effects experienced by patients include cramps, mild pain in the abdomen, nausea and so on.

However, some patients may show signs of complications. These should be reported to the physician as soon as possible; healthcare specialists should also define amniocentesis and its issues beforehand to every patient for better understanding of the procedure. The complications are – 

  • Some patients can develop an infection. Symptoms could be vaginal discharge, fever or leaking of amniotic fluid.

  • It can cause premature labour. Unusual pain in the abdomen is a symptom.

  • In rare cases, miscarriage and maternal/foetal haemorrhage may take place due to amniocentesis procedure.

  • The foetal may be injured by the needle during this procedure. 

You will find more amniocentesis articles on our website, which will help you to learn more about this procedure. You can also avail articles on other related topics and download them in PDF format through our mobile application to study from any device according to your convenience.

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FAQ (Frequently Asked Questions)

1. What is Amniocentesis?

Ans: Amniocentesis definition is that it is a medical process where a tiny amount of amniotic fluid is removed from the amniotic sac. 

2. Why is Amniocentesis Performed?

Ans: Amniocentesis is performed to detect any genetic defect in the foetus. It is also done to ascertain the condition of foetal lungs.

3. What are Some Complications Associated With Amniocentesis?

Ans: Some minor complications experienced by patients after this procedure includes cramps and mild pain. In rare cases, the patient may suffer from a uterine infection.