Amniocentesis test

Last Updated December 20th, 2021

What is Amniocentesis?

Amniocentesis is an invasive diagnostic test to evaluate the presence of genetic disorders and birth defects in the growing fetus. Amniocentesis is performed after extracting a minuscule sample of the amniotic fluid from the expectant mother.  The fluid which surrounds the unborn baby in the uterus is called the amniotic fluid.

Your specialist recommends this investigative procedure following an abnormal triple screening test during pregnancy. Amniocentesis involves examination of the amniotic fluid, made up of fetal cells and proteins, for the presence of certain medical conditions or disorders. Amniocentesis is performed between 14 and 20 weeks of pregnancy, although there are times when it is performed even at 11 weeks.

Since amniocentesis is an invasive technique, it is fraught with risks, such as miscarriage.

Why should I undergo Amniocentesis?

Amniocentesis helps throw light on the presence of birth defects and chromosomal abnormalities in the unborn baby. You may need to undergo Amniocentesis if other prenatal screening tests have aroused suspicion about the risk of genetic or neural tube disorders.

– Genetic amniocentesis: This test investigates the presence of genetic disorders and neural tube defects, such as Down syndrome, and Spina bifida in the growing fetus. This is usually performed between 15 and 20 weeks of pregnancy.

Lung power: This test evaluates the maturity of the fetus’ lungs and estimates lung behavior during birth. This test is not very common and is performed only when there is an absolute need. Only if delivery is being envisaged earlier than the expected date of delivery, then fetal lung maturity is evaluated with amniocentesis. This is performed anywhere between the 32-39 weeks of pregnancy.

– Drain excess fluid: It is also performed to drain out the excess amniotic fluid.

– Presence of Infection: To test the presence of other illnesses or infections, for instance, gauge the severity of anemia in babies with RH disease. This helps physicians assess whether the fetus may need blood transfusions.

Paternity test: Establishes paternity status with 99% accuracy, DNA from the fetus through amniocentesis is matched with the DNA of the potential father.

Although rare, amniocentesis is even performed in the third trimester if there is a rupture of membranes.

How is amniocentesis performed?

– This test is usually conducted in an outpatient clinic or in an office setting. It is better to have someone accompany you for the test. The procedure does not take longer than 10 minutes

– It is easier for your specialist to perform the test if the bladder is full, especially before 20 weeks of pregnancy. You may be advised not to use the toilet a few hours before amniocentesis. If the test is performed after 20 weeks, then your bladder should be empty as it reduces the risk of puncture.

– At first, an antiseptic is used to wipe your tummy clean and keep infection at bay.

– A thin and long needle is now inserted into the abdomen. Doctors use the ultrasound image as a guide to carefully direct the needle into the amniotic sac.

– A syringe now draws out a minuscule sample of amniotic fluid. This is later forwarded to the laboratory for testing. AT most times, it is not possible to draw out the fluid at the first attempt. Doctors often need to attempt a second time. In case this is not successful, healthcare providers prefer rescheduling another appointment for the procedure.

– After the test, you will be in close monitoring for about an hour to observe for any side effects such as excessive bleeding.

– If everything is okay, you are allowed to go home.

Do I need to fast for amniocentesis?

It is not required to be on an empty stomach before amniocentesis.

Do women experience pain during an amniocentesis?

Although few women compare the discomfort and pain during amniocentesis to the discomfort associated with menstrual cramps, this procedure is not really painful.  The slight pain experienced by most women is only when the needle is being pulled out after drawing the fluid.

Can I experience side effects after an amniocentesis?

Some common side-effects after amniocentesis which usually settles down on its own are:

Spotting and cramps: These are much like the menstrual cramps. If it is unbearable, Paracetamol is fine to reduce the discomfort, although you should not take aspirin or ibuprofen. It is better to rest and keep away from strenuous activity for the complete day.

Severe side effects which need medical assistance:

– High fever
– Severe and continuous pain
– Shivering and chills
– Contractions
– Leaking fluid from the vagina
– Excessive bleeding

What else should I know about amniocentesis?

You should be aware of some of the major risk factors of this procedure which may deter many women from undergoing it.

– One of the major risks of amniocentesis is miscarriage. Although amniocentesis is a safe procedure, it still remains an invasive technique. It can result in premature labor, water break because of an infection in the uterus all of which can cause miscarriage.

– Amniocentesis performed during the second trimester carries a minimal risk of miscarriage. Experts caution the risk of miscarriage with amniocentesis performed before 15 weeks of pregnancy.

– Although a sonogram is used to guide the needle during amniocentesis, in extremely rare cases, the needle can also pierce the baby. During amniocentesis, nearly 6 out of 100 women need reinsertion of the needle a second time to draw out the adequate amniotic fluid. The position of the baby makes it difficult to draw out the amniotic fluid.

– In a very rare occurrence, the amniotic fluid can leak out of the vagina after amniocentesis. The good thing is the fluid leak is minimal and in most cases, it settles down in a week, without any adverse impact on the pregnancy.

– Although it is extremely rare, you cannot completely discount a potential uterine infection after amniocentesis.

What are the instances where amniocentesis should not be performed?

– Infection such as Hepatitis B, Hepatitis C, and HIV AIDS can be transferred to the baby while performing amniocentesis. That is why healthcare providers advice against amniocentesis if you suffer from an infection.

– Most often genetic amniocentesis is recommended only if it can positively assist in pregnancy management.

Should I opt for an amniocentesis evaluation or not?

As a first step towards decision making, you should be aware of the benefits and risks of amniocentesis. Some couples do not want to undergo amniocentesis with the knowledge that it may cause harm to the growing fetus. The risk of miscarriage with amniocentesis is estimated as 1 in 400 cases. Some pointers which may help with the decision on amniocentesis:

– Worrying ultrasound results
Late pregnancy beyond 35 years of age
– Abnormal prenatal screening tests
– A genetic disorder in the previous pregnancy
– Presence of genetic abnormalities in the family

In the case of a confirmed diagnosis, the test offers a chance to remedy potential abnormality in the growing fetus. Parents can be prepared with a plan of action rather than be taken by surprise. It also helps parents cope with childcare by reaching out to support groups and addressing the special needs of the child.

You can count on your healthcare provider to help you weigh the benefits and risks of performing amniocentesis. The decision, of course, rests with the couple or the individual.

When will I get the results?

It takes about 3 days to process your amniocentesis test results. These results pertain to the presence of chromosomal conditions tested for. To get the result for other rare abnormalities, results may take about 3 weeks to process.

What do amniocentesis results mean?

You can rely upon the result of an amniocentesis test since it boasts of a high level of accuracy in the detection of chromosome abnormalities and neural tube defects.

– Out of 100 cases tested for amniocentesis, nearly 98 are accurate. Amniocentesis cannot, however, report the extent of disability. You may require the use of advanced ultrasounds and tests to measure alpha-fetoprotein levels to peg the extent of disability.

– A normal result implies that the conditions tested for were not found in the unborn baby. Since the test checks for the presence of certain genetic conditions and does not test for all abnormalities, it does not guarantee a completely healthy baby in every sense.

– In case you get a positive result, this means the baby has at least one of the conditions tested for. In case, your test turns positive, you need to plan the next course of action with your healthcare provider.

– Your healthcare provider can help you out with what to expect for babies born with the condition, and the options in front of you to make an informed decision.

– You can also choose to continue with the pregnancy, in which case you are prepared for a baby born with the condition. Or you could also choose to terminate the pregnancy.

– It is not an easy decision, but this test helps you prepare in advance for what is in store and seek support from specialists, friends, and family instead of dealing with it on your own.

How common are birth defects in India?

As per the latest WHO reports, globally there are 7.9 million cases of babies born with birth defects reported every year. More than 90% of these births occur in low and middle-income countries. 7% of all neonatal deaths can be attributed to birth defects. In India, roughly 60-70 cases per 1000 births are associated with birth defects.

What is the cost of Amniocentesis in India?

The cost of amniocentesis in India may range anywhere from Rs. 8000 to 15000. The costs of prenatal tests are mostly covered by insurance companies, especially if there are risk factors for chromosomal abnormalities.

What are the characteristics of the amniotic fluid?

The appearance of the amniotic fluid is a clear liquid that appears pale yellow in color. This fluid is made by the unborn baby. This fluid not only protects the baby against injury but also regulates temperature.  Amniocentesis can locate the presence of many genetic conditions and neural tube defects, even cystic fibrosis. Since some conditions cannot be detected prenatally, amniocentesis cannot enable a complete diagnosis of all genetic disorders and birth anomalies.

What are some of the dos and don’ts I should follow before the amniocentesis procedure?

Opt for amniocentesis especially if there are genetic disorders in the family tree or you had a previous child born with birth defects. Get disheartened with a positive result, as medical advancement can help with better management of genetic disorders.
Consider the benefits of amniocentesis if you are an expecting mother over 35 years of age.Avoid seeking immediate medical help in case of excessive bleeding or fluid leakage after amniocentesis.
Discuss in detail about the risks and benefits of amniocentesis before going for the procedure. Take adequate rest after amniocentesis.Take any decision in an impulse. The decision of continuing or terminating the pregnancy needs a lot of thought.

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