Amniocentesis is the process of examining the amniotic fluid in the laboratory environment by taking a sample from the amniotic fluid in which the baby swims in the mother’s womb. By examining the amniotic fluid, clear information about the baby’s chromosomes and genes is obtained. Amniocentesis is applied depending on the decision, request and approval of the mother and father candidates, if deemed necessary and recommended by the Perinatology (Risky Pregnancy Minor Specialist).
Prenatal diagnosis and screening tests are recommended to almost all expectant mothers. Amniocentesis is usually recommended by a Perinatology (Risky Pregnancy) Specialist when it is thought that there may be a possibility of a chromosomal disorder in the baby, and it should only be performed by a Perinatology (Risky Pregnancy) Specialist who has received special training in this regard. Screening tests and ultrasound observations give your gynecologist insight into the possibility of a genetic anomaly or a disease. Your doctor may also recommend amniocentesis based on this information. The decision to have an amniocentesis is made entirely by the mother and father candidates.
Conditions such as chromosomal disorder, genetic disease or infection can be diagnosed with amniocentesis, which is performed by taking a sample from the amniotic fluid, the fluid in which the baby is in the mother’s womb. This procedure, which takes a short time and carries a low risk, should be applied to pregnant women if deemed necessary by the physician in order to allow the definitive diagnosis of health problems that may threaten the mother and the baby.
As a short answer to the question of what is the amniocentesis test, it can be stated that it is the process of taking a sample from the amniotic fluid, which is the fluid in which the baby swims, in pregnant women. The amniotic fluid contains the baby’s cells. For this reason, many diseases can be diagnosed by examining the sample taken from this fluid under laboratory conditions. Although the most common reason for testing is suspected of chromosomal disorder, it is possible to diagnose many genetic diseases and infections by amniocentesis.
How is Amniocentesis Performed?
Amniocentesis is performed by inserting a thin needle from the abdomen into the uterus and taking a sample of the amniotic fluid. During the application, the expectant mother lies on her back and the Perinatology (Risky Pregnancy) Specialist detects the position of the baby and the placenta with ultrasound. In order to receive amniotic fluid, the doctor determines the appropriate area according to the position of the baby and placenta. It cleans the selected area with an antiseptic and reaches the amniotic fluid with the needle.
During the application, the expectant mother should lie still. Amniocentesis is performed without the need for local anesthesia as it is a short procedure and not a painful procedure.
Perinatology (Risky Pregnancy) Specialist draws the fluid into the syringe to take 15-20 ml of amniotic fluid and completes the procedure by removing the needle. After the procedure is completed, the baby is checked again with ultrasound.
Is it necessary to make a preparation before the amniocentesis procedure?
You do not need to make any preliminary preparations before the procedure. If your doctor asks you to drink water before the procedure, he will inform you about this. In amniocentesis applications performed before the 20th week of pregnancy, doctors may recommend that the bladder be full and that you drink plenty of water before the application. In applications performed after the 20th week of pregnancy, on the contrary, an empty bladder may be recommended.
What Should Be Done After Amniocentesis Application?
Bed rest is not required after the amniocentesis procedure, but it is recommended that the expectant mother avoid intense physical activities for a few days. During this period, exercise should not be done, sexual intercourse should not be performed, and should not stand for more than 15 minutes.
If the following conditions are observed after the amniocentesis application, you should immediately inform your doctor;
fever over 37.5 degrees
vaginal bleeding
Flow of amniocentesis fluid
foul smelling discharge
ongoing cramps
Redness or infection in the area where the needle was inserted
Immobilization of the baby or change in the baby’s movements
In Which Situations Is Amniocentesis Recommended by Doctors?
Advanced Maternal Age
It is usually recommended by doctors if the expectant mother is over 35. The most common criterion in recommending amniocentesis is the age of the expectant mother. Since the occurrence of Down syndrome and some genetic diseases is parallel to the age of the mother, the risk is seen in the mothers who are older.
Status of Previous Pregnancies
If the previous pregnancies of the expectant mother have been terminated due to a genetic problem, the doctor recommends amniocentesis.
Family Genetic History
Amniocentesis is recommended if the mother, father or close relatives have a genetic disease. If there is a genetic disease in the close relatives of both the mother and the father, if these come together by being carried from both the mother and the father due to the transfer of genes, they can cause a genetic disease in the baby. In order to rule out this possibility, amniocentesis is recommended for parents with genetic diseases in their families.
In people with a single gene disease in their family, it is ensured to examine whether this disease is present in the baby. This disease should be known beforehand, only this single gene should be investigated, and not all genes should be examined in such an examination.
Blood Incompatibility in Parents
If the mother and father have blood incompatibility and Rh disease has developed, amniocentesis is recommended to determine the degree of Rh disease.
When is Amniocentesis Performed?
Amniocentesis is a test applied in the second trimester of pregnancy, and it is performed at the earliest 16th week of pregnancy. Generally, amniocentesis applications are performed between 16 and 22 weeks of pregnancy.
When genetic testing is required before the 16th week, another test, CVS, that is, chorionic villus sampling, is recommended.
Which Diseases Cannot Be Detected by Amniocentesis?
Although the genetic structure of the baby is clearly revealed by amniocentesis, some disorders (congenital heart diseases, autism, structural anomalies such as cleft lip and palate) cannot be detected.
How Long Does It Take to Get Amniocentesis Results?
After the amniocentesis fluid is collected, the amniotic fluid is sent to the genetics laboratory for analysis. Amniocentesis results are analyzed in two stages. The first step, the FISH method called fluorescent technique, or the QF-PCR test, results are obtained within 2-3 days. FISH and QF-PCR tests provide results and preliminary information about certain chromosomes. For complete chromosome analysis, the result of cell cultures should be awaited. This may take 1 to 3 weeks.
What is the Success and Reliability Rate of Amniocentesis Results?
The accuracy of amniocentesis results is 99% reliable. Amniocentesis application may not yield results with a rate of 1%. Amniocentesis results will be reviewed and shared by the Perinatology (Risky Pregnancy) Specialist.
How is Amniocentesis Result Evaluated?
Amniocentesis results are mostly negative. If the test result is positive and a disease is detected, your doctor will share your options with you and maybe refer you to a geneticist.
What Are the Risks of Amniocentesis?
Low Risk
There is a risk of miscarriage of 1/300 to 1/500 in amniocentesis applications performed between the 16th and 22nd weeks of pregnancy. These rates are the data of Perinatology (Risky Pregnancy) Specialists. For this reason, it will be important to have this procedure done after you are sure that the Perinatology (Risky Pregnancy) Specialist will perform the amniocentesis application.
For amniocentesis applications made from the 16th week, it is not recommended to be applied before this week, since the risk of miscarriage reaches 4-5/100.
Needle Stuck in Baby
Sometimes, when the baby’s arm or leg moves during the amniocentesis application, the baby may be stuck with a needle. It is a rare condition that does not cause serious injury.
Cramps, Bleeding and Discharges
The expectant mother may experience cramping, vaginal bleeding and discharge of amniotic fluid. Leakage of amniotic fluid is a very rare condition, and the tear may heal spontaneously or may result in miscarriage if infection occurs. The incidence of bleeding is 2-3% and it goes away on its own without the need for treatment.
Infection Risk
Uterine infection after amniocentesis is very rare. Its incidence is 1/1000. It is important to perform the operation under sterile conditions in order to avoid the risk of infection.
Risk of Application Failure
After the application has started, the procedure may not be completed due to the inability to find a suitable entrance or the separation of the amniotic membrane from the uterine wall. In such a case, the application may be repeated within a few days.
Need for Repetition of Application
If the amniotic fluid taken is insufficient or bloody, the application may need to be repeated. Performing multiple trials from one application is not considered appropriate as it will increase the risks. It is more appropriate to repeat the application later.
It is very important for expectant mothers to be informed by doctors about why amniocentesis is needed, its content, expected results, and the risks and problems of applying or not performing amniocentesis. Expectant mothers may react to amniocentesis based on hearsay information. If there is a genetic disorder in the family or if it is suspected that there may be a genetic disorder in the baby, this should be clearly explained to the family, and the need for amniocentesis should be explained to the families in order to determine whether there is a genetic disease in the baby.
If a genetic disorder is detected as a result of amniocentesis, the process to be followed and the alternatives should be clearly explained to the families. Being prepared for the consequences that the families may encounter will be of great benefit to them at this stage.
Amniocentesis is used to eliminate or confirm the potential risks in pregnancy and to enlighten the mother and father candidates. According to the results of amniocentesis, terminating the pregnancy or continuing the delivery is entirely the decision of the family. In order to start amniocentesis, the consent and approval of the parents is obtained.
