Amniocentesis

Genetic Amniocentesis -

Amniocentesis can be done at any stage during the pregnancy for various reasons. Usually, it is performed after the 15^th week of pregnancy. It helps in identifying the following disorders or deformities in the fetus:

• Genetic defects
• Chromosomal disorders
• Body deformities
• Detects the severity of anemia in the developing fetus in the patients having Rh sensitization (a rare condition in which the mother's body produces antibodies against some of the baby's blood cells).

These issues, if detected early, assist the family and healthcare provider to assess beforehand regarding taking a decision on continuation or termination of the pregnancy. 

The procedure should be undertaken in some specific cases as mentioned below:

• If the previous prenatal screening test (e.g. noninvasive prenatal screening or first-trimester screening) results were unclear or positive.
• The age of the women carrying the baby is 35 years or above. At this age of pregnancy, the woman is considered to be at a higher risk of having a chromosomal disorder like Down’s syndrome.
• Any past genetic history of the pregnancy related issues is important as the present unborn baby might also be at risk.

 Family history of any genetic disorder related to the mother herself or her partner should be noted and taken care of while in the case of the present baby. History of genetic disorders might cause severe effects on the fetus like cystic fibrosis, sickle cell anemia, muscular dystrophy, and Tay-Sachs.

There are few risks associated with Amniocentesis as mentioned below:

• Miscarriage – Amniocentesis does carry a risk of around 1 in 500 cases of miscarriage. It is observed that chances of miscarriage are higher if the procedure performed before the 15^th week of pregnancy. Also, if the gestational age of the fetus is smaller than the normal age, there are increased chances of miscarriage. Some other cases like rupturing of the membranes may add to the risks.
• Leakage in amniotic fluid – In some rare cases, there might be a leakage issue of the amniotic fluid. If the leakage is sealed, then the pregnancy can be continued normally, but if it gets severe then there is an increased risk of the baby having orthopedic problems.
• Needle injury – This type of injury might occur if the fetus moves any part of the body in the path of the needle, however, chances of such injuries are rare.
• Infection – Amniocentesis might cause uterine infections in some women.
• Rh sensitization – In this condition, the mother develops antibodies against the baby's blood cells. This phenomena is rare and can be corrected by administrating a drug known as immunoglobulin after the amniocentesis procedure. The drug prevents the mother to produce antibodies against the fetus's blood cells.
• Infection transmission – If the mother is suffering from any condition like toxoplasmosis, hepatitis C or HIV, the same condition can be transferred to the body of the baby after amniocentesis.
• Premature delivery – Amniocentesis is associated with an increased chance of premature labor.

Before the procedure:

There are certain points which need to be taken care of in order to prepare for the procedure. If the amniocentesis is done before the 20th week of pregnancy, the urinary bladder should be full. The doctor advises to have lots of water/fluids before the procedure and refrain from urinating till amniocentesis is done. However, if the procedure is done after the 20^th week of pregnancy, the doctor advises having an empty bladder. 

There is a consent form which is to be signed before the procedure. Patient is often advised to get a companion along to provide emotional strength and accompany the pregnant woman safely to the home.

During the Procedure:

Amniocentesis is performed in the outpatient department as per the following steps mentioned.

• The woman is asked to lie down on her back on the examination table and the abdominal area is exposed.
• A special clear gel is applied on the surface of the abdomen to remove any air between the skin and transducer (a small device used in the ultrasound)
• Following this, the sound waves are sent out and the reflections are captured to form an image of the fetus on the monitor.
• By doing this the mother can be shown the picture of the baby inside the womb.
• Then abdomen is then cleansed with an antiseptic and a fine hollow needle is inserted into the abdomen to reach the uterus.
• Through the syringe, a small sample of the amniotic fluid is extracted and the needle is removed. The amount of the sample fluid collected depends on the weeks of pregnancy.
• The procedure helps to detect any birth abnormalities, deformities, chromosomal disorders, genetic issues. The doctor can easily measure the size of the head and thighbone of the fetus along with the details of its growth and development. The doctor can also record the heartbeat, weight and any complication in the fetus easily.
• With this ultrasound, the doctor can know the exact gestational age of the fetus.

 After the Procedure:

The following steps are performed after completing the procedure.

• The procedure takes approximately 20 to 30 minutes to complete and the collected sample is sent to the lab for further detailed analysis.
• There might be some vaginal bleeding after the procedure. So, the patient is advised to avoid extreme physical activities for at least two days.
• After the procedure, the woman is sent back home.
• In some cases, there might be heavy bleeding from the vagina, abdominal pain, cramps in the uterus, continuous leakage of fluid from the vagina, fever, lack of baby movements or extreme unusual baby movement, inflammation (redness) at the site of needle insertion. In such scenarios, the doctor must be informed immediately.
• After receiving the reports, the doctor explains the observations to the pregnant mother in detail.

The doctor will explain the results of amniocentesis in detail to the expectant mother. This procedure assists in ruling out genetic problems in the fetus at an early stage. However, the procedure cannot detect all types of birth disorders. In case the results show that the fetus has a disorder that cannot be treated, then the family has to make a difficult decision on whether to continue or terminate the pregnancy. Amniocentesis is of great help when it comes to managing the pregnancy. If the result of the procedure is negative, it means that the baby is in a healthy state and is growing normally. In the case of abnormal results from the procedure, the doctor might advise the expectant mother to go for some other prenatal tests to have a better confirmation. In case of maturity amniocentesis, the results of the test can assertively indicate the maturity of the lungs and inform to the doctor that if the delivery is expected early, then the baby is ready to be born or not. However, the accuracy of amniocentesis is considered 100%, but there might be certain cases wherein the amniotic fluid sample collected is not enough or when the sample is sent to the lab, the cells do not grow properly as expected. In such cases, the results might not be 100% accurate.

Q1. When can the expectant mother start doing normal activities, after the procedure?
A1. The pregnant mother is advised to go home and have rest for the day, when amniocentesis is done. If there are no problems or complications observed, then the expectant mother can start with the normal routine activities the next day of the procedure. However, the mother is still not advised to perform any strenuous exercise or sexual contact for few days.

Q2. When can the results of the procedure expected?
A2. It might take 2 weeks for the results to come from the lab. However, the doctor can tell the family some related information in 2-3 days.

 Q3. Is it mandatory to go for amniocentesis?
A3. No, it is not mandatory to go for this procedure. The doctor will counsel the expectant mother and explain all the required information including the advantages and risks before the procedure. It is the choice of the mother whether to opt for amniocentesis or not.

Q4. At which time during the pregnancy it is safe to go for amniocentesis?
A4. If the doctor advises for this procedure, then it is better to get it done after the 15^th week of pregnancy. Usually, the procedure is performed before the 20^th week of pregnancy.