What is Amniocentesis?

Dr Priya Sharma

Dr Priya Sharma

BDS (Bachelor of Dental Surgery), 6 years of experience

September 13, 2021 Womens Health 426 Views

English हिन्दी Bengali

What is the meaning of Amniocentesis?

Amniocentesis is a test that may be prescribed to you by your doctor to assess any genetic or chromosomal abnormalities in the foetus. It is not a routine test prescribed to everyone in pregnancy but may be offered to women falling in the high-risk category, to ensure that the pregnancy isn’t complicated and the fetus is healthy.

In this procedure, amniotic fluid is removed from the uterus to test for genetic abnormalities and other developmental disorders of the fetus. This may include the prenatal diagnosis of the well-known Downs Syndrome.

Another group of mothers that Amniocentesis is suggested to are those that have previously conceived children with genetic abnormalities or have a history of complicated pregnancies.

As mentioned above, this prenatal test is considered essential if there is a family history of genetic disorders or some abnormality in the ultrasound. Amniocentesis can also detect neural tube defects such as spina bifida and anencephaly and is capable of determining the sex of the baby (Currently, illegal in India). Usually, it is done in the 15th to 18th week of pregnancy. 

In pregnancy, the words “test” and “procedure” become common, even though possibly alarming. Therefore, it is very important to be educated and informed about terms that might pop up in the course of one’s pregnancy. One such term happens to be “Amniocentesis”.

Let’s uncover what Amniocentesis is through today’s article.

  • What are the causes for Amniocentesis?
  • What is Amniotic Fluid?
  • What are the steps done before Amniocentesis?
  • What is the procedure of Amniocentesis?
  • What are steps of care after Amniocentesis?  
  • What are the risks of Amniocentesis?
  • Frequently asked questions (FAQ’s) about Amniocentesis
  • What is the cost of Amniocentesis in India?

What are the causes for Amniocentesis?

The amniocentesis test is an invasive one, meaning the doctor needs to gain access to the person’s body fluids, more specifically the amniotic fluid, via the introduction of a needle. It is a relatively painless procedure, with the pain being comparable to that felt during a routine blood test.

Although invasive, the procedure is extremely helpful for the doctor to diagnose chromosomal and genetic abnormalities in the fetus, even before it is born. This test is usually done between the 15th to 20th weeks of pregnancy. 

Amniocentesis may help detect the following conditions in the fetus:

  • Genetic or Chromosomal Conditions– Like Down’s Syndrome (a genetic disorder where there is developmental and intellectual delays), Edward’s Syndrome (a birth defect where the baby has low birth weight, abnormally shaped head, organ defects), or Patau’s Syndrome ( where the child has a severe intellectual defect and many physical defects like abnormal head shape, extra fingers, and toes, etc) ( Know more about- What is Premature Baby? )  
  • Sickle cell anaemia ( Disorder where the red blood cells are abnormal sickle shaped which leads to rapid damage to red cells and symptoms like fatigue, dizziness, chest pain,etc)
  • Open Neural Tube Defect (ONTD) – These are the birth defects caused due to abnormal development of brain, spine and spinal cord. Examples- spina bifida, anencephaly,etc. Children may have an abnormal sac like bulging from the back of neck, head or may have abnormal small head. ( Know more about- What is Shaken baby syndrome? )
  • If Maternal age is over 35years, at the pregnancy due date, then Amniocentesis may be advised to check for any genetic birth defects.
  • Cystic Fibrosis (This is a life endangering disorder where the lungs and the digestive system of the person are damaged. Here the fluids in the body become thick and they block the tubes and ducts in the body leading to complications).
  • Muscular dystrophy– Group of genetic diseases where due to abnormal genes, there is continuous muscle damage and weakness, leading to loss of muscle mass. 
  • Tay-Sachs disease-  This is a rare disorder where a certain type of fatty substance in the brain destroys nerve cells in the brain and spinal cord. 
  • Abnormal screening tests– Amniocentesis can be done if the other maternal screening tests show some pregnancy related abnormality. 
  • Rh disease (Erythroblastosis Foetalis)- It is the hemolytic disease or anemia of the newborn babies where the red blood cells of the baby get destroyed by the mother’s activated immune system due to blood group incompatibility between the mother and the fetus.
  • Incases of suspected Sex linked Genetic Diseases– In certain genetic disorders like Hemophilia and Duchenne muscular dystrophy, where the mother is the carrier of the abnormal X chromosome, the fetus may have a high chance of getting the disorder. Amniocentesis helps in detecting the presence of any such abnormal chromosomal defects.
  • Inherited metabolic disorders– Amniocentesis may help in detecting inherited metabolic disorders ( rare genetic disorders that lead to improper functioning of the person’s metabolism) like Hunter’s Syndrome, Maple Syrup Disease,etc.
  • Fetal infections– like Toxoplasmosis, varicella, rubella, etc may be carried from mother to the developing fetus via placenta and may lead to birth defects, morbidity or mortality in the fetus. ( Know more about- What is Fetal Echo Test?)
  • Maternal uterine infections– Chorioamnionitis is the bacterial infection of the maternal urinary tract, that starts in the vagina, anus or rectum of the mother and may spread upto the uterus lining where the developing fetus is present. Amniocentesis may help in detecting such uterine infections that are harmful to the developing fetus.
  • Fetal lung maturity analysis– In cases of early delivery, amniocentesis is done to detect the fetal lung maturity by analysis of components of the amniotic fluid like lecithin, L/S ratio, P factor.  
  • Follow-up tests, if any early similar tests show abnormality.

What is Amniotic Fluid?

Amniotic fluid is a jelly-like, pale, clear yellow fluid or substance that protects the baby during pregnancy in the amniotic sac, the fetus’s first home in the uterus. It contains enzymes, proteins, hormones, and fetal cells in abundance and therefore, can be used to obtain information about the fetus. Amniotic fluid also protects the baby from infections, helps the baby move easily in the womb and develop properly. Amniotic fluid also maintains the temperature of the fetus.

What are the steps done before Amniocentesis?

Before 20 Weeks of Pregnancy:

If amniocentesis is being done before 20 weeks of pregnancy, it is recommended to keep the bladder full during the procedure to support the uterus. Drink plenty of fluids before your appointment.  ( Know more about- What is Female Fertility Panel? )

Post 20 Weeks of Pregnancy:

If this procedure is being done after 20 weeks of pregnancy, it is advised to keep the bladder empty. Apart from this, motivate the woman to stay strong mentally and physically.

It is important to note that this procedure is completely elective, that is you do not have to have it if you don’t consent. The doctor, midwife, or medical practitioner will make sure they inform the patient of all the benefits & risks associated with the procedure along with the procedure in detail. ( Know more about- What is C-section Delivery? )

What is the procedure of Amniocentesis?

  • During amniocentesis, first, the doctor will ask the woman to lie down comfortably. 
  • Then, the doctor will apply a numbing jelly to the area they will carry out the procedure in, most commonly the lower half of the abdomen.
  • Subsequently,  a thin needle will be inserted into your abdomen to collect a sample of amniotic fluid from the womb. According to some women, this test procedure feels as painful as taking a blood sample with a needle.
  • Anesthesia is given before the procedure to numb the site of injection as mentioned, in the form of a fine needle. This may sting a bit, however, research shows that most women aren’t benefitted from this. 
  • The above procedure takes about 10 minutes. 
  • Ultrasound is done after taking a sample of the fluid. Although a needle is used to remove the fluid, the doctor secures the baby and the placenta using USG monitoring via ultrasound. ( Know more about- What is PCOS? Symptoms and Treatment )

A family member should accompany the woman during the procedure. After the amniocentesis examination, do not drive or ask someone to drive you home. Rest for at least one day after this procedure.

What are the steps of care after Amniocentesis? 

Amniocentesis is usually done when the pregnancy is about 16-20 weeks old, that is in the second trimester. 

After amniocentesis, the heart rates of the mother and fetus are monitored. You may feel minor cramping after the procedure. It is necessary to rest for at least a day and avoid all kinds of physical exercise.

Contact the doctor in the following cases:

What are the risks of Amniocentesis?

Amniocentesis involves several risks. These involve common ones like abdominal cramps and rarer complications such as miscarriages ( 0.3% probability)

Other risks may include:

  • Infection or bleeding may occur at the injection site.
  • During the test, there is a possibility of amniotic fluid leakage from the vagina.
  • If done in the second trimester of pregnancy, there are chances of miscarriage as well.
  • During amniocentesis, a needle injury may occur that may harm the fetus.
  • During this procedure, the baby’s blood cells can enter the mother’s blood.
  • If the mother has HIV or an infection such as hepatitis C, the infection can be transmitted to the baby during amniocentesis.

The risks are slightly higher when carried out earlier in pregnancy, around up to 15 weeks.

If the fetus and the mother have differing Rh statuses, a certain component found in the blood, the doctor may administer RhoGAM to prevent any interactions and adverse events.

Frequently asked questions (FAQ’s) about Amniocentesis

Can I get back to normal day-to-day activities after amniocentesis?

It is best to take a rest for the entire day after amniocentesis. One should not do any heavy physical exercise or lift anything heavy or have sex for a day or two after the procedure. 

When should I call the doctor after Amniocentesis?

Call your doctor immediately if you have symptoms like high fever, severe abdominal cramps, pain, bleeding, or vaginal discharge.

How much time does it take for the results of the Amniocentesis test?

The test results of Amniocentesis are generally available within 2 to 3 weeks’ time.

How reliable is the Amniocentesis test?

Amniocentesis is usually reliable and accurate 99.5 percent time. Sometimes there can be technical issues like an inadequate collection of amniotic fluid samples, etc , which rarely happens.

What is the alternative to Amniocentesis?

Chorionic Villus Sampling (CVS) is the alternative to Amniocentesis. This test also helps to detect genetic diseases. This can be done earlier in pregnancy than Amniocentesis. 

Which is better- Amniocentesis or CVS?

CVS has the advantage that it can be performed earlier in the pregnancy at 10-13 weeks, compared to 15-20 the week of Amniocentesis. However, Neural tube defects like spina bifida can not be detected with the CVS test. 

What is the cost of Amniocentesis in India?

The total cost of Amniocentesis in India can range from around INR 8000 to INR 20,000. Although there are many hospitals and specialist doctors in India for Amniocentesis, the cost of Amniocentesis may vary across different hospitals.

If you are coming from abroad, then along with the cost of Amniocentesis, there will be an additional cost of staying in a hotel, the cost of living, and the cost of local travel. So, the total cost of Amniocentesis comes to be around INR 9,000 to INR 23,000.

We hope that we could answer your questions regarding Amniocentesis through this article.

If you need more information about Amniocentesis, you can contact a Gynecologist/Obstetrician.

We only aim to provide you with information through this article. We do not recommend any medicine or treatment. Only a doctor can give you the best advice and treatment plan. 

Over 1 Million Users Visit Us Monthly

Join our email list to get the exclusive unpublished health content right in your inbox