Amniocentesis: everything you need to know about the method of invasive diagnostics. Amniocentesis - indications, contraindications, possible complications, cost, reviews Amniocentesis indications

Amniocentesis- an invasive procedure consisting in the sampling of amniotic fluid with a puncture needle through the anterior abdominal wall. Most often, this method is used to diagnose congenital diseases of the unborn child, but can be used to administer drugs and reduce the amount of amniotic fluid.

Amniocentesis is safe for the body of the unborn child; if performed correctly, its diagnostic benefit exceeds the possible harm. This procedure allows you to detect congenital pathology of the fetus in time and decide on the termination or prolongation of pregnancy.

Indications for amniocentesis

Diagnosis of congenital diseases. An invasive study is ordered after an increased risk is identified during perinatal screening. Amniocentesis allows the removal of amniotic fluid containing cells with the chromosome set of the fetus. After a puncture using modern equipment, doctors can determine the pathology of the genome. Amniocentesis allows you to identify chromosomal abnormalities in the unborn child - Down syndrome (triple of chromosome 23), Patau (triple of chromosome 13), Edwards (triple of chromosome 18), Turner (lack of one of the X chromosomes), Klinefelter (doubling of the X chromosome in boys).

Control of fetal hemolytic disease. This disease is observed in Rh-conflict associated with the activation of the immune system of the expectant mother. Hemolytic disease of the fetus causes the breakdown of red blood cells necessary for the respiration of all tissues. Amniocentesis allows you to count the amount of maternal antibodies in the amniotic fluid, thanks to which the doctor determines the severity of the disease.

Determination of the quality of lung tissue. Analysis of amniotic fluid during pregnancy allows you to calculate the amount of surfactant - a substance necessary for breathing atmospheric air. Indications for this study are diseases such as severe preeclampsia, placenta previa, chronic renal failure.

Control of sterility of fetal waters. Doctors prescribe a puncture of the amniotic fluid after the mother has suffered a serious illness of bacterial or viral etiology - rubella, syphilis, toxoplasmosis.

Amnioreduction. This procedure is aimed at reducing the amount of amniotic fluid by puncturing it and isolating it from the uterine cavity. Amnioreduction is used to treat polyhydramnios.

Fetotherapy. Amniocentesis can be used to inject drugs into the amniotic sac.

Dates

The optimal time for amniocentesis for the diagnosis of congenital diseases of the fetus is the period from 16 to. Amniotic fluid puncture for other purposes is possible until the end of the gestation period.

Amniocentesis: when is it necessary and is the procedure safe for the fetus

Amniocentesis Accuracy

The sensitivity of amniocentesis may decrease with a mosaic type of chromosomal anomaly - when some of the fetal cells have a normal genomic set. However, this variant of the pathology is rare, occurs in 0.1-1% of all congenital diseases.

The specificity of the diagnostic procedure in assessing the maturation of the surfactant and the degree of hemolytic disease is also close to 100%. At low concentrations of infectious agents in the amniotic fluid, amniocentesis may give a false negative result.

Contraindications

#1. Threat of spontaneous abortion. Performing amniocentesis during increased uterine tone increases the likelihood of an adverse pregnancy outcome.

#2. Pathology of the structure of the uterus. Congenital anomalies, tumor formations of the organ can cause difficulties during the procedure. In the worst case, amniocentesis provokes damage to the uterine wall.

#3. Acute inflammatory diseases. If there is a focus of infection in the body of the expectant mother, there is a risk of infection of the fetus during amniocentesis.

Amniocentesis Risks

After amniocentesis, 1-2% of expectant mothers are at risk for several days. This complication is a normal reaction of the woman's body, it does not pose a threat to the life of the fetus. The woman's body quickly replenishes the deficiency of the lost amniotic fluid.

If amniocentesis was performed more than 3 times, there is a possibility of detachment of the amniotic membranes. That is why doctors should control the frequency of invasive research methods, not prescribe them without strong indications.

Failure to follow the technique of performing amniocentesis can lead to intrauterine infection of the fetus. The presence of disposable and sterile instruments prevents this complication.

In the presence of a Rh conflict, there is a possibility of a worsening of the course of the disease against the background of amniocentesis. To prevent complications, doctors administer to expectant mothers special drugs that destroy antibodies.

Improper performance of the procedure can contribute to premature rupture of amniotic fluid and stimulation of labor. However, this complication is rare, it occurs only after a gross violation of the amniocentesis technique.

Preparation

A few days before the puncture of the amniotic fluid, the expectant mother is sent to donate blood and urine for general tests. These studies help to establish the presence of a focus of infection in the body. For the same purposes, a pregnant woman should take a smear on the flora from the vagina.

The day before the procedure, a pregnant woman is shown an ultrasound examination. It is aimed at clarifying the gestational age, as well as determining the position of the placenta, the amount of amniotic fluid, the anatomical features of the structure and position of the uterus.

Preparation for analysis includes taking drugs from the antiplatelet group for 5 days before the proposed study of the amniotic fluid. They are designed to prevent possible thrombus formation at the puncture site.

If an amniocentesis is performed after 20 weeks of gestation, the expectant mother should empty her bladder immediately before the procedure. If the amniotic fluid puncture is scheduled at an earlier time, the woman needs to drink a liter of water an hour before the study.

At the consultation, the doctor informs the expectant mother about the rules for conducting amniocentesis, the need for its appointment, as well as about possible risks and complications. After that the woman must sign the consent to take amniotic fluid puncture. If desired, the pregnant woman can refuse the procedure.

Holding

The puncture is carried out using a syringe equipped with a needle. Before the puncture, the mother's abdomen is treated with an antiseptic. The first 5-10 milliliters of amniotic fluid are drained because they contain mother's cells and are not suitable for research.

For examination, the doctor takes about 25 milliliters of amniotic fluid., then removes the needle from the anterior abdominal wall. After that, the skin of the mother's abdomen is re-treated with an antiseptic. A pregnant woman should remain in the supine position for 5 minutes.

results

After obtaining a sufficient number of fetal cells laboratory assistants conduct genetic research. It includes counting the number of chromosomes, as well as determining the markers of some hereditary diseases - cystic fibrosis, sickle defect of red blood cells, etc.

Also, laboratory assistants examine the amniotic fluid for the presence of pathogens of infectious diseases. According to the indications, specialists determine the amount of surfactant and maternal antibodies to fetal erythrocytes.

The study of amniotic fluid takes a certain period of time, it usually takes about 7 business days to get results. The conclusion about the procedure contains information about the sex of the fetus, its genotype, the number of chromosomes. It also indicates the detected pathogens, the titer of maternal antibodies and the degree of maturity of the lungs of the fetus.

After receiving the results, the expectant mother can know with almost one hundred percent probability whether the child has a congenital chromosomal abnormality. If the conclusion indicates the pathology of the fetal genome, the woman must decide whether to continue or terminate the pregnancy.

If maternal antibodies or infectious agents are found in the amniotic fluid, further treatment tactics are discussed with the doctor. The specialist prescribes a course of therapy aimed at preventing pregnancy complications.

The amount of surfactant in the amniotic fluid is of decisive importance in further decision making in the presence of diseases that are a contraindication for prolonging gestation.

Recovery after the procedure

Alternatives

Cordocentesis is a study that involves taking blood from the umbilical cord of the fetus using a puncture needle through the anterior abdominal wall. This procedure is carried out under ultrasound control not earlier than at the 18th week of pregnancy. The optimal time for cordocentesis is the middle of the second trimester. The study helps to identify congenital pathologies of the fetus, as well as the amount of hemoglobin, platelets, bilirubin and other substances in the blood of the unborn child.

A child developing in the mother's womb for 9 months is in the fetal bladder, which is filled with amniotic fluid. It consists of nutrients that saturate the baby, and his waste products. In some cases, when ultrasound and other tests cannot reveal an obvious pathology that can threaten the life and health of a small organism, amniocentesis is prescribed - one of the most difficult prenatal procedures. There are many different myths about him that scare many pregnant women. To dispel them, you need to clearly understand what it is and how dangerous it is.

Amniocentesis prescribed at different stages of pregnancy is an invasive (i.e., penetrating through the natural barriers of the body: skin, mucous membranes) procedure. It consists in a puncture (puncture) of the amniotic membrane in order to:

• obtain amniotic fluid for laboratory testing;
• carry out amnioreduction - pumping out amniotic fluid if there are too many of them (the so-called);
• introduce drugs for artificial termination of pregnancy in the II trimester;
• pour the necessary medicines into the amniotic cavity.

This procedure is quite specific, and therefore the timing is of great importance. The best option is to meet the interval from 16 to 20 weeks of pregnancy. Depending on this parameter, there are several types of amniocentesis.

Classification

Depending on the timing of amniocentesis and what tools are used, the following types of procedures for penetrating the amniotic membrane are distinguished.

By timing:

• early: performed in the first trimester of pregnancy (starting from 8 and inclusive to 14 weeks);
• late: appointed after the 15th week.

According to the execution technique:

• the use of a puncture adapter, which allows you to make a more accurate puncture without touching nearby tissues;
• the "free hand" method, when the doctor himself directs the needle.

If a woman has been prescribed an amniocentesis, it is better for her to familiarize herself with this procedure in advance, find out what it is and for what purpose it is carried out. This is not an ordinary laboratory study or some kind of routine analysis. If a doctor sends a pregnant woman for a puncture of the amniotic fluid, then there are some concerns that he must definitely acquaint the expectant mother with.

Indications

There are certain medical indications for this procedure. The decision is made if ultrasound or tests give fuzzy, vague results, and doctors have all the fears that there may be some problems with the fetus that threaten its health or life. So, which amniocentesis reveals, associated with both heredity and external factors:

• in the first trimester, hereditary and congenital diseases are diagnosed at the gene level (read more about);
• in the II and III trimesters, the severity of hemolytic disease, the degree of maturity of lung surfactants, and the presence of intrauterine infections are detected.

However, amniocentesis during pregnancy is prescribed not only to determine some serious illness. There are other indications for its implementation:

• polyhydramnios (amnioreduction is performed);
• artificial termination of pregnancy in the terms of the II trimester with the help of drugs;
• if the puncture of the amniotic fluid is needed to prepare serum from the embryonic tissues of the fetus, which is from 16 to 21 weeks: many diseases are treated with their help (the so-called fetotherapy);
• fetosurgery.

If there are such indications, an amniocentesis procedure is prescribed, which in most cases gives almost 100% results. That is why it is used as the latest, but reliable source of information about the state of the baby in the womb. But the doctor makes such a decision only under one condition: if there are no contraindications.

Wow! Amniocentesis can detect up to 200 gene mutations and diseases in the fetus. Among them, the most common are Down, Patau, Edwards, Turner and Klinefelter syndromes.

Contraindications

Despite the complexity of the procedure and the dangerous consequences that it can entail, there are not very many contraindications for its implementation. You can not prescribe the analysis of amniotic fluid by puncture in the following cases:

• the course of acute processes: women are not at all unreasonably worried about whether it is possible to do amniocentesis for a cold, since it is better to wait for a complete recovery from any seasonal sores;
• premature detachment of a child's place;
• exacerbation of localized chronic inflammation;
• urogenital infections;
• anomalies and pathologies of the uterus;
• risk of miscarriage;
• large tumor-like neoplasms in the muscular layers of the uterus;
• problems with blood clotting;
• abnormal location of the placenta (for example, on the anterior uterine wall).

In addition to all this, a woman has the right to refuse an amniocentesis if she is afraid of complications. But in this case, the doctor must explain to her in detail the consequences of such a decision. Then an alternative to amniocentesis is offered - chorion biopsy or. Each of them has its own advantages and disadvantages. In the absence of contraindications and with the consent of the pregnant woman, the date of amniocentesis is prescribed.

Execution technique

When prescribing such a study, it is better for a woman to know in advance how amniocentesis is done in order to fully prepare for it, and not to worry in vain during the procedure itself. This information can be studied in detail on the Internet (even watch a video), or you can get advice from your doctor.

Preparation

Preliminary preparation for amniocentesis is as follows.

1. A woman passes all the necessary tests and undergoes an ultrasound scan to identify infections, multiple pregnancy, the condition of the baby in the womb, the amount of amniotic fluid, and clarify the gestational age.
2. A week before the procedure, you need to stop taking acetylsalicylic acid and all drugs containing it.
3. The day before the amniocentesis, it is not allowed to use anticoagulants (low molecular weight heparins).
4. Parents sign consent to the procedure.

If the preparatory stage satisfied the doctor, he directly conducts the amniocentesis analysis itself, making a puncture.

Analysis

1. Amniocentesis is done in a special room where all sanitary standards must be observed.
2. The pregnant woman is laid on the couch.
3. The analysis is carried out under the supervision of an ultrasound, so that the woman’s stomach is first lubricated with a sterile gel.
4. Then, guided by the ultrasound data, the doctor inserts a needle into the abdomen and pumps out amniotic fluid (about 20 ml).
5. After the data is taken, the fetal heartbeat is checked to make sure it is normal.

Rehabilitation

Rehabilitation after amniocentesis is not required, but bed rest for 24 hours is recommended. If a woman is still working, she is issued a sick leave for 7 days. Any physical activity is excluded. For those pregnant women who have a negative Rh factor, anti-Rhesus immunoglobulin is injected for 3 days. Analgesics and anti-inflammatory drugs may be prescribed.

Feel

One of the most exciting questions for everyone waiting for this analysis - is it painful to do an amniocentesis - does not have a definite answer. Reviews about this procedure are different for everyone. Someone does not feel anything, someone - a slight tingling or heaviness in the abdomen. Although there are those who, when asked whether it hurts or not, they say that at the time of the puncture - yes. Discomfort and discomfort are always present, but nothing more. In this case, doctors do not recommend anesthesia, since you will have to endure two injections instead of one.

In most cases, the analysis is carried out without failures and unforeseen circumstances. Amniocentesis in modern clinics is put, as they say, on the conveyor. Every year, the number of women who are sent to the study of amniotic fluid to eliminate doubts about gene diseases in the baby is increasing.

Decryption

Getting the amniotic fluid out is only half the battle. The doctors are still ahead - deciphering the amniocentesis, which will either refute the suspected diagnosis or confirm it.

According to statistics, the reliability of the results of this study is about 99.5%. That is why it is so valued among doctors who prescribe it in most doubtful cases in order to avoid mistakes.

The most curious need to know what the result of an amniocentesis looks like in order to calm down as much as possible. Usually, parents are given an A4 document in their hands, which shows the chromosomes of the fetus, and the diagnosis is indicated below.

Since the analysis is done mainly to identify gene abnormalities, the norm - either 46XY (boy) or 46XX (girl) - is a good result, indicating a healthy baby. If, for example, the diagnosis of Down syndrome is confirmed, the number will be 47, since this disease is characterized by the presence of 47 chromosomes in the child.

Interesting Facts. Deciphering amniocentesis is a capacious and long procedure (up to 2 weeks), since the following tests are carried out: fetal karyotype (cytogenetic study), chromosomal microarray (listed in the results as XMA), biochemical, immunological, hormonal.

Complications

Invasive procedures are always unpredictable and can affect the womb in which this puncture is made in a variety of ways. Therefore, the consequences of amniocentesis, although rare, still occur. Among them, the most common and undesirable are:

• amniotic fluid earlier than usual, and this threatens in the early stages - a miscarriage, in the later stages - premature birth, but at the same time, absolute calmness must be observed if there is only a slight leakage of water after amniocentesis, which is quite possible within a day after the analysis, and then stops;
• detachment of the fetal membrane;
• infection most often occurs when amniocentesis is done in the second trimester: during this period, the antibacterial activity of amniotic fluid is minimal;
• possible short-term discharge in small quantities for 1-2 days after analysis;
• the fetus may develop alloimmune cytopenia (deficiency of certain blood cells).

Despite the fact that such complications still exist in medical practice, one must understand that these are only isolated cases, dictated, for example, by non-compliance with contraindications. So before the analysis, the parents, together with the doctor, must weigh the pros and cons: how much do they need this puncture?

Unpleasant consequences. Within 2-3 days after amniocentesis, a woman may experience vomiting, nausea, pain in the lower abdomen, and purulent discharge at the puncture site. All this is not the norm and requires immediate medical advice.

Pros and cons

After hearing about the negative consequences that this procedure can entail, many women think about whether to do an amniocentesis or not, will complications arise after it, for which they will then have to pay for their whole lives?

This is where you need to talk to your doctor. How big is the risk of having a sick baby and what diagnosis is he supposed to have? If it's Down Syndrome, think about the hard life of this child in the future. At the same time, complications after the procedure are diagnosed much less frequently and they are not as dangerous as they are told. In addition, when asked if there is an erroneous amniocentesis, doctors will answer you unequivocally: no. Few in whose practice the result turned out to be unreliable.

This procedure is highly recommended for all women who have been diagnosed with any abnormalities in the development of the fetus at different stages of pregnancy, especially at the gene level. Moreover, the results of amniocentesis have such a high percentage of reliability with minimal risks and complications.

The consequences are extremely rare (only 2-3% of cases), but it is better for parents to learn about such serious diseases as Down syndrome in advance in order to prepare for this mentally and make the only right decision.

Since December 27, 2017, at the Genomed Medical Genetic Center (Rostov-on-Don), it is possible to perform amniocentesis - a study of amniotic fluid taken with a thin needle through a microscopic puncture in the abdomen of the expectant mother. This procedure is a simple surgical operation that allows doctors to obtain very important information about the child's condition. DNA analysis of fetal cells helps to confirm or refute the presence of genetic diseases in the baby.

Usually, amniocentesis is performed for diagnostic purposes when the attending physician is alerted by the results of an ultrasound or screening test. It is also prescribed to those women who have acute polyhydramnios, there are medical indications for termination of pregnancy, or surgical treatment of the fetus is required.

Since this procedure carries the threat of miscarriage, it can only be carried out by a super professional doctor! That is why, for the amniocentesis, the MHC "Genomed" invited a doctor of ultrasound diagnostics, Ph.D. Kokh L.V. one of the best professionals in the industry. Reception Lilia Vladimirovna conducts every Wednesday. Pre-registration is required.

Biography Kokh L.V.:

In 1998 she graduated from Rostov State Medical University with a degree in General Medicine.

From 1998 to 2000, she completed residency at the Rostov Research Institute of Obstetrics and Pediatrics.

In 2008, on the basis of the Rostov State. Medical University defended her thesis on the topic "Assessment of the adaptive-compensatory capabilities of the fetus when choosing the time and method of delivery in pregnant women with diabetes."

Kokh L.V. constantly improving and has documents confirming advanced training:

Certificate of advanced training - Training and Research Center "CoMeT" on the basis of the Scientific Center for Cardiovascular Surgery named after. A.N. Bakulev RAMS on the topic "Intrauterine diagnosis of the pathology of the cardiovascular system."

Certificate of advanced training - Institute for Advanced Studies of the Federal Medical and Biological Agency on the topic "Actual issues of complex prenatal diagnostics" Fetal echocardiography. Dopplerography in obstetrics” (2006).

Diploma of professional retraining - Kuban State Medical University under the program "Ultrasound Diagnostics" (2007).

One of the methods of prenatal (prenatal) diagnosis of the fetus is amniocentesis. This procedure consists in the sampling of amniotic fluid with further hormonal, biochemical, cytological (study of the chromosomal composition of fetal cells) and immunological analysis.

Indications for amniocentesis

Since amniocentesis refers to invasive procedures, its implementation is prescribed strictly according to indications:

• detection of congenital and hereditary diseases (study of the karyotype of the obtained cells, determination of the number of chromosomes and their structure);
• unfavorable results of a screening study (deviations on ultrasound, in a biochemical blood test - a “triple” or “double” test);
• the need to introduce drugs into the fetal bladder for early termination of pregnancy;
• the age of the woman (at 35 years of age or older, the risk of having a child with chromosomal abnormalities increases);
• amnioreduction (removal of excess amniotic fluid with polyhydramnios);
• monitoring the condition of the fetus (determining the degree of maturity of the lungs, the production of surfactant (a substance that prevents the lungs from collapsing on a breath), the severity of fetal hemolytic disease);
• determination of intrauterine infections;
• fetotherapy (intra-amniotic administration of drugs for the treatment of the fetus);
• fetosurgery (treatment of the fetus in an operative way);
• the birth of a child with a hereditary pathology in history;
• burdened family history (the spouses have relatives with hereditary diseases or chromosomal abnormalities).

Contraindications

The procedure is contraindicated in the following situations:

• threatening placental abruption;
• the possibility of abortion (threat);
• malformations of the uterus;
• tumors of the muscular layer of the uterus;
• feverish condition of a woman;
• inflammatory diseases in an acute form or during an exacerbation.

Preparing for an amniocentesis

Before the procedure, a woman is assigned a routine laboratory examination (KLA, OAM, vaginal smear). In addition, a mandatory ultrasound is performed on the eve of the procedure to identify the localization of the placenta, the number of fetuses in multiple pregnancies, clarify the gestational age and the amount of amniotic fluid, and identify various anatomical features that can affect the conduct of amniocentesis. Also, before manipulation, you should not take antiplatelet agents and anticoagulants for 5 days - drugs that thin the blood and reduce its coagulability (aspirin, chimes, heparin).

If amniotic fluid is taken before 20 weeks, then the woman must come to the procedure with a full bladder. At 20 weeks or more, amniocentesis is performed with an empty bladder.

Before manipulation, the woman is informed about the procedure, possible risks, and is asked to sign a consent form for amniocentesis.

Technique

The procedure begins with an ultrasound, during which a pocket of amniotic fluid is determined, free from umbilical cord loops and the edges of the placenta. All manipulation is also carried out under the control of ultrasound. Amniocentesis is often performed without anesthesia, but local anesthesia with a 0.5% novocaine solution is also possible. The selected area of ​​the skin of the anterior wall of the abdomen is treated with an alcohol solution of an antiseptic, after which the doctor pierces the skin, subcutaneous fat layer and the wall of the uterus with a puncture needle, which is attached to a syringe, and then sucks out the amniotic fluid.

The first 0.5 ml of amniotic fluid is unsuitable for research, since they may contain woman's cells, so they are poured out. The next fluid intake is 15-20 ml, after which the needle is removed, and the puncture site is re-treated with an antiseptic. For an hour, the woman is offered to rest. The whole procedure takes 2-3 minutes.

Amniocentesis results and further tactics

The accuracy of the study of amniotic fluid and the diagnosis of congenital and hereditary diseases reaches 99%. After the amniotic fluid is obtained, it is delivered to the laboratory and the fetal cells are isolated from it. These cells are planted on nutrient media to increase their number. Cytogenetic analysis of normal waters shows the content of 23 pairs of normal, without structural abnormalities of chromosomes.

• By the quantity and quality of chromosomes, it is possible to determine the presence of such chromosomal diseases as Down syndrome, Edwards, Patau.
• Identify/confirm neural tube malformations: anencephaly and spinal hernia.
• Cytogenetic analysis of the amniotic fluid reveals hereditary diseases (cystic fibrosis, sickle cell anemia), which are not normally present.
• Also, a study of the fluid reveals intrauterine infection (herpes, rubella).
• Allows you to determine the group and Rh factor of the fetus and gender, which is important for predicting some hereditary diseases linked to the Y chromosome with the X chromosome (for example, hemophilia).
• Determine the severity of fetal hemolytic disease and decide on further tactics of pregnancy management.

In addition, in some cases (for example, severe preeclampsia, not amenable to therapy), it is necessary to identify the degree of maturation of the lungs of the unborn child and decide on premature delivery. The degree of lung maturation is assessed on the ratio of lecithin and sphingomyelin (biochemical analysis of water):

• L / C is 2/1 - full maturity of the lungs;
• L / C is 1.5 - 1.9 / 1 - in half of the cases, the development of respiratory distress syndrome is possible;
• L / C is 1.5 / 1 - in 73%, the development of respiratory distress syndrome is not excluded.

If abnormalities are detected, the doctors decide on the issue of further tactics of pregnancy management by a council.

In case of detection of gross, incompatible with life fetal defects or chromosomal and hereditary diseases, the woman is offered to terminate the pregnancy. If she refuses to interrupt, she is entered into a high-risk group and a specialized maternity hospital is selected for the delivery of women in labor with a similar pathology.

With hemolytic disease of the fetus or the detection of intrauterine infection, appropriate therapy is prescribed, and the optimal timing for delivery is determined.

In some cases, when anomalies in the development of the fetus that do not threaten its life are detected, the tactics of treating the fetus with the possible conduct of fetotherapy or fetosurgery is selected.

During pregnancy, for various reasons, a violation of the condition of the fetus can occur. The child is surrounded by amniotic fluid - amniotic fluid, which also contains living cells of his skin, exfoliated, but in the process of growth, and other substances. Their study helps to find out valuable information about the health of the fetus, and this diagnostic method is called amniocentesis.

What is amniocentesis?

Amniocentesis is a method for examining amniotic fluid. It is a piercing of the abdominal wall of the uterus. In the process of its implementation, a small amount of amniotic fluid is taken and a number of studies are carried out: hormonal (quantity, composition of hormones), immunological (identification of violations in individual links of immunity), biochemical (composition of amniotic fluid). The summary analysis of these fluid studies helps to determine the general condition of the fetus and determine the risk of genetic abnormalities.

What pathologies can be detected by amniocentesis

There are several hundred varieties of genetic defects that can be detected by amniocentesis, including chromosomal diseases (Edwards, Patau and Down syndromes), neural tube defects (spinal hernia, etc.).

However, congenital defects such as cleft palate and cleft lip are not shown by amniocentesis.

Indications for the study

The decision to use the amniocentesis method can only be taken by a pregnant woman, since this procedure is associated with certain risks. And opinions about the appropriateness of this study differ. First of all, you need to be prepared for the fact that if an anomaly is detected, you may have to terminate the pregnancy. However, early detection of a defect in a child will give time to find out what help may be needed.

And since amniocentesis poses some threat to the health of the mother and her child, this test is offered only to women who have significant prerequisites for the development of genetic diseases in the fetus, including in cases where:

• An ultrasound revealed a serious problem, such as a defect in the heart, which may indicate a chromosomal abnormality;
• According to the results of screening tests, there is a risk of having a baby with chromosomal abnormalities;
• One or more relatives of the woman and / or the child's father have some genetic abnormalities;
• A pregnant woman is over 35 years old, since from this age the risk of having a sick child increases - 1 case in about 300 (for comparison, at the age of a mother of 20 years, this ratio is 1 to 2000).
• The woman has already had a pregnancy with genetic abnormalities in the fetus.

Amniocentesis - timing and method

The amniocentesis method is used at 16 to 18 weeks of gestation (i.e. 14 weeks after the first day of the first menstruation that did not occur). However, if the doctor has reason to suspect that the fetus has a heart defect or a serious genetic disease, then amniocentesis is allowed for up to 14 weeks.

Also, in some individual cases, amniocentesis is also performed at later dates for the purpose of artificial termination of pregnancy, if there are medical indications for this. In this case, a concentrated salt solution or other drug is injected into the bladder.

The obstetrician-gynecologist conducts this diagnostic test in the operating room. Before the procedure, a pregnant woman must do an ultrasound to determine the location of the placenta in order to avoid damage during the puncture.

The puncture itself is made through the anterior abdominal wall of the uterus, after treating a small area of ​​the skin of the abdomen with a five percent alcohol solution of iodine. The puncture site is anesthetized with local anesthesia to reduce discomfort. Under the control of ultrasound, the doctor inserts a thin long hollow needle into the amniotic cavity and collects 15-20 ml of fluid, which is sent for laboratory analysis. In the laboratory, all chromosomes are counted and their structure is determined, but the procedure takes two to three weeks. The fact is that for diagnostic purposes, a certain number of baby cells are needed, which are grown in special conditions, which is why a woman does not receive results immediately.

Immediately after the amniocentesis, patients may experience pain in the abdomen.

Some people have minor spotting after the amniocentesis. Therefore, as a rule, the doctor recommends bed rest during the day.

Also, after the amniocentesis, the doctor will check the baby's heartbeat for some time and observe the woman to prevent possible uterine contractions.

Contraindications for amniocentesis

• the presence of a benign tumor in the uterus;
• malformations of the uterus;
• the location of the placenta on the anterior wall of the uterus;
• the threat of termination of pregnancy;
• infectious processes or febrile conditions.

Consequences of amniocentesis

Conducting this study is associated with some risks. Possible side effects of amniocentesis include:

• The development of infection or other complications (in one in 200 women);
• Bleeding in a woman or fetus;
• Feeling contractions for several hours after the procedure is the most common consequence of amniocentesis;
• Miscarriage of a healthy child (1 case out of 500);
• Spontaneous abortion. An Rh-negative mother is given an injection of Rho-gamma globulin before the procedure to protect her baby from her antibodies. In 2 cases out of 100, it is this injection that provokes a miscarriage;
• Injury to the fetus (the likelihood of such a consequence of amniocentesis is almost zero, but, nevertheless, it is possible if the doctor touches the vital area of ​​\u200b\u200bthe child with a needle);
• Damage to the fetal bladder, which leads to bleeding and outflow of amniotic fluid (the patient will have to lie down for preservation, treatment can take up to several months);
• premature birth.

Given all of the above, every woman, before agreeing to a test, must take into account the possible consequences of an amniocentesis and weigh the pros and cons. In addition, the test result still cannot guarantee the birth of an absolutely healthy child, it only excludes some pathologies. Its accuracy is approximately 99.4%. Therefore, every pregnant woman should consult a geneticist and only then make a final decision.