Placental mosaicism may affect the results of amniocentesis. Amniocentesis - indications, contraindications, possible complications, cost, reviews. Lack of culture growth

Under pseudomosaicism understand mosaicism, which does not reflect the true chromosomal constitution of the individual and is caused by the presence of individual cells with a chromosome set that differs from the karyotype of the main cell population. In this case, a single cell may have a chromosomal abnormality (unicellular pseudomosaicism) or various chromosomal abnormalities may occur in several cells (multicellular pseudomosaicism).

In preparations from cultured cells fixed by the in situ method, pseudomosaicism is recorded if abnormal karyotype demonstrates a cell in one area of ​​the colony, or all metaphase plates of one colony, or several colonies. With the flask method, pseudomosaicism refers to the presence of numerous cells with the same type of chromosomal abnormality within one flask.

Frequency of pseudomosaicism, according to summary data from different laboratories, varies between 0.6-1.0%.

Mosaicism limited to the placenta

As noted above, PD chromosomal abnormalities carried out on the cells of either the fetus or provisional organs. For the interpretation of PD results, the features of the origin of the analyzed material can be of fundamental importance. Thus, the chorionic cytotrophoblast, being a derivative of the trophectoderm, as well as the mesodermal stroma of the chorionic villi/placenta are separated from the inner cell mass at the blastocyst stage, i.e. are of extraembryonic origin. The amnion, formed from the primary ectoderm, is an embryonic structure. All epithelial cells of the AF, as well as umbilical cord blood lymphocytes, are of embryonic origin.

At post-implantation stages human development chromosome set in the cells of the fetal membranes, as a rule, corresponds to the karyotype of the fetus. However, in some cases, karyotype discordance in cells of extraembryonic tissues and the fetus is possible. In this case, the mismatch of chromosome sets can be complete or have a mosaic form. Cell lines with an abnormal karyotype can be localized in the tissues of both the extraembryonic membranes and the fetus. The presence of an abnormal cell clone in the tissues of the fetus when present in the placenta (i.e., true or generalized mosaicism) is confirmed in 10% of cases of placental mosaicism, or accounts for 0.1% of all developing pregnancies. According to the generalized results of PD, cases of mosaic aneuploidy in fetal tissues that have a normal karyotype in the cells of provisional organs are rare. In approximately 2% of advanced pregnancies, cytogenetic abnormalities, most often mosaic trisomies, are limited to the placenta.

Type classification placenta-limited mosaicism is given in table. It is believed that placental mosaicism is unfavorable factor for fetal development. Risk of intrauterine growth retardation, spontaneous miscarriage, antenatal death or premature birth characteristic of cases of placental mosaicism with a fairly high proportion of aneuploid cells in the cytotrophoblast, in the extraembryonic mesoderm, or in all tissues of the placenta (types 1, 2 and 3 of placental mosaicism, respectively). However, various approaches to assessing the obstetric and clinical manifestations of placental mosaicism do not currently allow us to consider its effect on fetal development as absolutely proven.

It is obvious that it is important question about the type of mosaicism can only be solved in the case of parallel analysis of cytotrophoblast and mesoderm, i.e. combining the direct method of preparing drugs with the cultivation of chorion or placenta samples. Necessary diagnostic steps in cases of mosaicism should also include establishing the origin of the trisomic line (stage and mechanism of occurrence), as well as excluding uniparental disomy. These studies are especially important when mosaicism involves chromosomes for which the phenomenon of chromosomal imprinting has been established.

Sometimes it happens that the expectant mother’s well-founded fears for the health of the child in her womb are very serious. And then, if the doctors’ forecasts regarding the condition of the pregnant baby are disappointing.

We have to resort to diagnostic methods that allow almost full confidence affirm or deny the presence of incurable developmental disorders in the fetus. One of the most commonly practiced procedures for this purpose is amniocentesis.

It was for diagnostic purposes that amniocentesis was first performed in 1966.

A decade earlier in amniotic fluid were able to determine the cells of the fetus and its gender.

Until this time, puncture of the amniotic sac was used back in the century before last as a method of treating polyhydramnios, as well as for the purpose of killing the fetus at a later stage.

The essence of the “Amniocentesis” method is to take amniotic fluid (amnion) to determine the karyotype of the fetus and confirm the expected diagnoses, namely:

• Down syndrome;
• Patau syndrome;
• Edwards syndrome;
• diseases caused by pathology of the development of the neural tube of the fetus;
• cystic fibrosis;

Amniocentesis is also performed to identify complications of the current pregnancy, including intrauterine infection.

In some cases, when early delivery is necessary, amniocentesis is used to assess the development of the baby’s lungs, as well as for amnioreduction, and for carrying out prenatal treatment measures for the fetus.

Invasive diagnostic methods, including amniocentesis, have been widely used since obstetric practice introduced ultrasound control.

Until this time, punctures were carried out blindly, which, of course, did not guarantee the safety of manipulation with the needle for the expectant mother and baby.

When is amniocentesis performed?

Amniocentesis analysis can technically be performed at any stage of pregnancy, however, early amniocentesis (before the 15th week) is rarely performed and for special indications due to the small amount of amniotic fluid at that time.

Amniocentesis, in order to make a diagnosis of genetic diseases of the fetus, is carried out at 16–24 weeks of pregnancy (optimally at 16–20 weeks), so that parents have the opportunity to make a decision about the fate of the pregnancy.

Indications and contraindications: to do or not?

Amniocentesis, as a procedure that involves penetration into the body of a pregnant woman, and, therefore, carries certain risks for the condition of the future mother and fetus, should be performed exclusively for medical reasons and in cases where the risk from the procedure does not exceed the risks from the development of postoperative complications .

• there are age-related risks of fetal development pathologies, that is, the age of the expectant mother is more than 35 years;
• showed a disappointing prognosis for the development of incurable congenital diseases in the fetus;
• the parents of the unborn baby may be carriers of hereditary diseases or diseases caused by chromosomal abnormalities;
• During previous pregnancies, the woman carried a fetus with developmental defects.

In addition, invasive intervention may be necessary during pregnancy if:

• a puncture is necessary for medical measures (intrauterine therapy, surgery) for certain types of complicated pregnancy (polyhydramnios, intrauterine infection, etc.);
• For medical reasons, it is necessary to terminate the pregnancy in the later stages.

Contraindications to amniocentesis, due to the high risks of subsequent complications for the condition of the pregnant woman and the fetus, are:

• infectious diseases in the acute stage, fever;
• large myomatous nodes;

Even if the expectant mother, according to some selection criteria, is among those who are indicated for amniocentesis, she will first have to consult a geneticist who, in each individual case, evaluates the need for the procedure, weighing all possible risks.

How to prepare for the procedure

If there are medical indications for a future woman in labor, amniocentesis can be performed at the expense of social insurance, if there is such a technical and technological possibility in a laboratory serving pregnant women in the areas of antenatal clinic.

And, as before any surgical intervention, the expectant mother will have to provide medical information upon request. staff analysis results of the “small preoperative collection”:

• clinical blood and urine test (not older than 1 month);
• Rh blood group analysis;
• markers of infectious diseases in the blood: HIV, syphilis, hepatitis B, C (not more than 3 months old).

Some institutions may also request ultrasound results.

The most difficult part of preparing for amniocentesis for a woman, apparently, is moral readiness. And this is important. Often, the safety of the procedure and the physical condition of the patient after it depend on the woman’s calmness.

As a rule, no other preparations are required. Perhaps, with early diagnosis, the expectant mother will be asked to come with a filled bladder. With late amniocentesis, on the contrary, the patient should empty her bladder and bowels before the procedure.

For hygienic reasons, a woman should take a change of underwear with her, since the puncture site is generously treated with antiseptic liquid, which, of course, will saturate the clothes.

Mommies with negative Rh factor blood, care must be taken to ensure that after the procedure they receive an injection of anti-Rhesus immunoglobulin, in order to avoid consequences due to Rh conflict.

An injection of immunoglobulin is given only if the fetal blood is Rh positive.

Immediately before the operation, the woman will have to express in writing her consent to undergo amniocentesis, and also confirm that she possible risks she is familiar.

How to carry out the procedure

Depending on the rules of the procedure in a particular medical facility. institution, the woman’s early arrival is required for preoperative preparation: a preliminary examination of the pregnant woman, an ultrasound scan to assess her condition and the condition of the fetus, and the absence of contraindications for invasive intervention.

Under the strict control of an ultrasonic sensor, the puncture site is selected: as far as possible from the fetus and umbilical cord arteries, preferably without affecting the placenta.

If it is impossible to obtain the required amount of material for analysis extraplacentally (as in the case of localization of the placenta along the anterior wall of the uterus), then an area of ​​the least thickness is selected to puncture the placenta.

The site of the intended puncture is treated with an antiseptic, sometimes additionally with a local anesthetic. In general, the operation is considered painless.

Most women who have undergone amniocentesis confirm that the sensations during the doctor’s manipulations can hardly be called painful, rather a slight tugging, and the pain of the puncture itself is comparable to the sensations during a regular injection.

The puncture is made with a fairly thin puncture needle, in most cases, penetrating into the amniotic sac through the peritoneum and myometrial walls.

Transvaginal or transcervical amniocentesis, as a rule, is not performed in the second trimester due to the higher likelihood of developing postoperative complications during pregnancy.

After the needle has entered the amniotic sac, about 20 ml is taken through its hole. amniotic fluid, which contains embryonic cells. Moreover, the first 1 - 2 ml. fluid is neglected because it may contain cells from the mother.

The resulting material is sent to the laboratory for research, depending on the purposes of amniocentesis.

If it was not possible to obtain the required amount of liquid the first time, the puncture is repeated.

After removing the needle, doctors monitor changes in the well-being of the pregnant woman and fetus for some time using ultrasound. It is even possible to place the patient in a hospital.

If the outcome of the operation is successful and there are no negative consequences it is not expected that it will be carried out, the woman is discharged with a sick leave certificate upon request.

For several days after amniocentesis to the expectant mother a gentle regimen is prescribed. If any alarming symptoms appear: discomfort at the puncture site, etc., you must consult a doctor immediately.

Amniocentesis for multiple pregnancies

For case c, both single and double insertion of the needle through 1 puncture may be required.

In the first case, the needle enters one of the amniotic cavities and, after taking fluid from it, the needle is advanced to puncture the septum between the cavities and take fluid from the second bladder. In the second case, access to the fetal bladder occurs with different needles through multiple punctures in the woman’s abdominal cavity.

In order to avoid repeated sampling of amniotic fluid from the same amniotic sac, the amniotic fluid of one of the twins is tinted with a safe dye.

When will the analysis results be ready?

In the standard course of examination of fetal cells, the results of amniocentesis become known 14 to 28 days after the procedure.

Readiness times depend on the test method and the rate of fetal cell division.

The fact is that the amniotic fluid obtained during collection contains a very small number of fetal cells, which is insufficient for full testing.

Therefore, for a detailed analysis of the presence of possible anomalies in the fetus, preliminary cultivation of its cells selected from the amniotic fluid is required for 2 to 4 weeks in order to obtain the required number.

If, after this time, active cell division has not been achieved, or the material has been lost for some reason, then the woman will have to undergo a repeat amniocentesis.

If honey The institution where the woman undergoes amniocentesis has a laboratory technically equipped to conduct it, then results for some chromosomal pathologies - trisomies - can be obtained within 24 hours.

Conducting an accelerated study is more complex and therefore more expensive. It is usually carried out for an additional fee.

Where can I get amniocentesis?

If the expectant mother has the opportunity to choose honey. institutions to undergo the procedure, even at their own expense, then you should focus primarily on the reviews of your predecessors about the professionalism of doctors performing surgical interventions, on the statistics of negative consequences caused by punctures and manipulations with a needle in this clinic, etc.

To undergo amniocentesis in Moscow, expectant mothers most often turn to the following medical institutions:

The price of the procedure may include, in addition to non-operative services provided by the clinic to its patients, also an accelerated cell analysis by the “direct” method (FISH test) with the provision of preliminary results.

Reliability of results

The reliability of amniocentesis, according to doctors, is close to 100%, or more precisely 99.5%. This applies to tests for those genetic abnormalities that the task is to identify.

The remaining 0.5% for errors includes cases in which the following occurs:

• mixing of maternal cells with fetal cells during amniotic fluid sampling;
• mosaicism occurs;
• when cells undergo mutation during their cultivation;
• in case of loss of fetal cellular material after collection;
• errors due to the “human factor”.

It is, of course, impossible to diagnose all possible genetic diseases in the fetus. The analysis is carried out for those pathologies that occur most often (by nationality) and/or that are suspected based on preliminary non-invasive studies specifically in this case. Amniocentesis will not show non-genetic defects.

Are there any complications?

Amniocentesis, compared to other invasive research methods, is considered the safest procedure.

The probability of developing complications after it is less than 1%, according to medical statistics.

Of course, the density of negative consequences after amniocentesis in relation to the total number of operations performed for each practicing doctor depends on his experience, the professionalism of assistants and the quality of auxiliary equipment.

In addition, the risk of complications after the intervention also depends on the woman’s health status and the course of pregnancy.

The consequences of amniocentesis can be:

• leakage of amniotic fluid (which requires the woman to be admitted to a hospital and undergo conservation therapy);
• intrauterine infection of the woman and fetus;
• injury to the fetus, umbilical cord arteries;
• loss of the fetus due to spontaneous abortion.

However, we should not forget that according to statistics, the probability of spontaneous abortion even with a normal pregnancy is about 1.5%. Therefore, a disastrous pregnancy outcome after invasive intervention may be a coincidence and not a consequence of amniocentesis.

Is amniocentesis necessary?

A conversation with a geneticist will help the expectant mother make a decision about the need for an invasive examination. His task is to evaluate everything possible consequences undergoing amniocentesis or refusing it individually for each mother, taking into account the risks of preliminary examinations and the woman’s medical history.

There may be a high probability that the pathology confirmed by the results of amniocentesis is accompanied by deep damage to the baby’s vital organs, and then the prognosis for his life expectancy after birth may be disappointing.

However, the patient must make the final decision independently, discussing the pros and cons of the procedure with her family.

The basis for a family verdict should be whether the parents can adequately care for and love a child with developmental disabilities. And also about how much the quality of life of the rest of the family will deteriorate when a baby appears in the house, requiring increased attention.

One can have a long discussion about the moral side of amniocentesis, but the vast majority of women who have undergone it do not regret it and are grateful to the creators of the procedure for the opportunity to find out about the condition of their baby in the womb and make the only right decision for themselves.

23.06.2009, 16:45

43 years old, third pregnancy, 15 weeks. We did a villocenetesi test at week 13, I think in Russian it would be cordoncentesis (they took a substance from the placenta). Mosaicism of 2 chromosomes was discovered (out of 16 chromosomes, 5 chromosomes are defective). The normal karyotype is (boy). Unfortunately, for now this is all I have in my hands. this moment I don’t have a diagnosis, as soon as I get it I’ll post it.
They suggested doing amniocentesis to clarify the diagnosis - they did it on June 22. We are still waiting for the results. As soon as I receive them, I will also post them.

My question is, what kind of pathology is mosaicism of the 2nd chromosome and what prospects can the child have?
Best regards, Ksenia

23.06.2009, 22:44

Unfortunately, I can’t say anything without the karyotype formula.
Do you have a conclusion? Does it say "normal karyotype"?

24.06.2009, 13:16

Nata,
The problem is that I took the villocentesi test with QF-PCR on June 3. According to the rules, if they find something, they inform you within 10 days. More time passed for us, I went to the gynecologist for an appointment and asked how the result was, he replied that if they didn’t call you, then everything is fine. Then enough time passed and they called back and asked to come urgently for an appointment. From the words of the gynecologist it followed that the main chromosomes 13, 18, 21 X and Y were normal, but mosaicism of some second chromosome surfaced. I also urgently underwent amniocentesis, but so far there are no results.
The problem is that my second child - a daughter - has sexual trisomy. Then they explained it to us simply as a mutation, but now mosaicism is emerging. I don’t know what to think, and even more so what to do.
Thank you for your answer, as soon as the results are sent, I will post them.

24.06.2009, 17:38

I think that you should not associate your daughter’s trisomy with possible features karyotype of this child.

Without the final result, indeed, nothing definite can be said.
We wait.

29.07.2009, 00:09

Hello, Nata!

So, we have finally received a conclusion.
An amniocentesis was performed on June 22, a control ultrasound was performed on July 1, and no external abnormalities were detected.

Karyotype 46, XY

Conclusion

No quantitative or structural changes in chromosomes were detected.

So I’m thinking, where could the mosaic cells be located? In the placenta? Or in the fibroid, which is located above the placenta? And how can this affect the child?
Thank you in advance
Ksenia

29.07.2009, 00:11

I forgot to add that I’m already 20 weeks pregnant.

29.07.2009, 00:24

Hello Ksenia!
Very good result of amniocentesis :).

This incomprehensible mosaic does not matter. Maybe this is a feature of the placenta cells. It happens, it won’t affect the child in any way.

29.07.2009, 10:51

Nata,
Thanks for the quick response. You calmed me down, otherwise I was twitching all the time from the unknown. Now I can breathe calmly. On August 5 I am going to a scheduled appointment with a gynecologist. I hope that everything will be alright.
Thank you again
Ksenia

Modern medicine has reached such a level that it has become a very real and everyday thing for doctors to examine unborn babies and identify some serious pathologies of fetal development long before the child is born. Moreover, doctors today can even carry out certain medical procedures in utero. Prenatal diagnosis and therapy - that’s what these techniques are called. These include cordocentesis. Many expectant mothers are frightened by the prospect of undergoing such a procedure. What is cordocentesis? And should I be worried about this analysis?

Description of the method

Cordocentesis is a puncture of the fetal umbilical cord vessels to collect cord blood and subsequently study it for the presence of fetal chromosomal abnormalities and other pregnancy pathologies.

To determine fetal diseases associated with heredity and chromosomal pathologies, it is best to take cord blood for analysis - blood from the umbilical cord connecting the placenta and the fetus. It is this examination that obstetricians-gynecologists consider the most informative and accurate. This diagnosis is called cordocentesis (puncture of the umbilical cord vessels).

A prerequisite for its implementation is the presence in your antenatal clinic (or medical center) of an ultrasound machine and, of course, specially trained, highly qualified personnel.

Umbilical cord blood is collected under continuous ultrasound control

Fetal pathologies, syndromes detected using cordocentesis:

• Patau syndrome (trisomy 13);
• Edwards syndrome (trisomy 18);
• Down syndrome (trisomy 21);
• monosomy on the X chromosome - Shershevsky-Turner syndrome;
• polysomy on X chromosomes, polysomy on Y chromosomes - Klinefelter syndrome;
• cystic fibrosis;
• Duchenne disease;
• thalassemia;
• hemophilia and other genetic diseases;
• intrauterine infection.

Cordocentesis is also carried out for the purpose of:

• implementation of intrauterine (prenatal) drug therapy;
• determining the indicator of intrauterine growth retardation - the acid-base balance of the fetus;
• identifying causes pathological condition fetus;
• carrying out therapeutic blood transfusions - for alloimmune, autoimmune conditions.

Compared to other diagnostic methods, cord blood analysis eliminates erroneous results and allows you to obtain the most complete information about the condition of the fetus in the mother’s womb, about its development and the presence of hereditary and genetic pathologies.

However, considering it a priority compared to, say, amniocentesis or chorionic villus biopsy is not allowed by the fact that the manipulation itself is quite difficult to perform. This is due to determining the optimal puncture site, the mobility of the fetal umbilical cord and other objective factors.

Therefore, they resort to it only in certain cases: if accurate information about the baby’s condition is urgently needed or when drug therapy for the fetus is necessary.

Video “Cordocentesis - collection of umbilical cord blood of the fetus”

For what period is it carried out?

On early stages During pregnancy, the volume of blood circulating in the umbilical cord is not yet large enough. Therefore, taking the amount required for analysis may negatively affect the condition of the fetus.

In this regard, it is not recommended to take cord blood for testing until the 18th week of pregnancy, but it is better to wait until 21–24 weeks. It is by this time that its volume increases, and the diameter of the vessels reaches the dimensions necessary for analysis. And this also matters when carrying out manipulation.

Indications

Cordocentesis is not included in the list of mandatory tests. Expectant mothers are referred for invasive examination for certain medical reasons.

What are the indications for puncture of the umbilical cord vessels?

1. Age of the pregnant woman (over 35 years old). There is such a concept - “age threshold for pregnancy”. The older the expectant mother, the greater the risk of having a child with chromosomal abnormalities.
2. Non-compliance with results standards biochemical test in the first trimester.
3. Poor results of the second screening.
4. Hereditary diseases that cause deviations in physical and mental development, in the anamnesis of one of the parents.
5. Previous pregnancies aggravated by fetal malformations.

In such situations, doctors prefer to determine the karyotype of the fetus (the number and quality of its chromosomes) as early as possible. To be able to respond adequately if the results of the analysis turn out to be unfavorable - to determine further tactics for managing the pregnancy or, as a last resort, to terminate it at an early stage.

If at the very beginning of pregnancy, if indicated, for some reason karyotyping of the spouses (blood test for karyotype) was not performed or it turned out to be insufficiently informative, cordocentesis is used to determine the karyotype of the fetus.

In addition, this analysis may be required if:

• some complications during pregnancy;
• diagnosing diseases in the mother while carrying a baby that have the ability to cause fetal malformations;
• suspected intrauterine infection in the fetus;
• when there is a need for fetotherapy (administration of blood products, medications).

Contraindications

However, even if there are medical indications for prenatal diagnosis, some pathologies of pregnancy may become an obstacle to its implementation. And only your attending physician can assess the risks and decide on the advisability of invasive intervention.

• threat of miscarriage;
• acute infectious diseases in the expectant mother;
• the presence of large myomatous nodes in a woman.

Preparing for the study

The first thing you should be prepared for when going for a test is that in most medical institutions you will be asked to stay in the hospital after the procedure to monitor the condition of the fetus. This is necessary so that doctors have the opportunity to respond in a timely manner to possible complications.

Therefore, it would be useful to have a change of underwear and personal hygiene products with you. In some centers, on the eve of diagnosis, expectant mothers are recommended to perform preliminary hygiene of the pubic area.

You must provide:

• results of blood and urine tests (validity period no more than 2 weeks);
• vaginal smear (not more than 3 months old);
• results of examinations for hepatitis B, C, HIV, syphilis (statute of limitations no more than 3 months);
• referral to a geneticist for diagnosis;
• screening ultrasound protocols (on request).

Immediately before the procedure, you will be asked to give your written consent to cordocentesis.

Before you go to the operating table to collect cord blood, you will undergo a thorough examination using an ultrasound machine, which will help clarify the timing and condition of pregnancy and determine the location of the placenta. And only after this, during the manipulation itself, the puncture site will be determined using an ultrasound sensor.

If the expectant mother is very worried before the puncture, she is given a sedative. The abdomen will be treated with an antiseptic and, if necessary, a local anesthetic will be administered.

Algorithm and diagnostic methods

Technically, the manipulation, like other invasive procedures, is carried out either using the “free hand” method (more often) or using a puncture adapter (less often).

The puncture can be single-needle or double-needle.

1. Single needle puncture. After the amniotic sac is punctured, a puncture of the umbilical cord vessel is made with the same needle, a syringe is attached to the needle and the amount of cord blood required for diagnosis is taken (1–4 ml), and then the needle is removed.
2. Double needle puncture. In this case, a double needle is used: inside the large outer one there is a small one. The amniotic membrane is punctured first with a large needle. They bring it to a pre-selected point on the umbilical cord, and then they puncture the umbilical cord vessel with a small one and take cord blood for analysis. After which the needles are removed from the uterine cavity in the reverse order.

The operation is carried out under the continuous monitoring of an ultrasound machine, and in the third trimester, CTG (cardiotocography) is also used to monitor the condition of the fetus.

This is what puncture needles look like for invasive interventions and for ultrasound sensors

Sequencing

1. The site of intervention is determined using an ultrasound sensor. The puncture should not affect the placenta. But there are situations when it is technically impossible to meet this condition. Then they try to mark the thinnest area on it.
2. To obtain only fetal material (without any admixture of maternal material), the puncture is performed on the area of ​​the free loop of the umbilical cord. It is, of course, more mobile, but the results of the analysis will be more reliable.
3. If necessary, the fetus is immobilized with medication.
4. The duration of the manipulation is about 30 minutes.
5. After cordocentesis, the expectant mother remains in the hospital for 1–2 days under the supervision of doctors.

Cord blood collection is considered a painless procedure.

When to expect results

Cord blood does not require cell cultivation in an incubator. This is material ready for research. That is why the waiting time for analysis results is relatively short - only a few days (no more than ten).

The higher risk of complications after cordocentesis (compared to other invasive methods of prenatal diagnosis) is justified by the possibility of obtaining quick results. And in some cases, it is the time frame that is vital.

Reliability of the analysis

As for the results of cordocentesis, there is no doubt about their reliability. When cultivating cells obtained, for example, by collecting amniotic fluid (amniocentesis), their mutation is possible, which affects the accuracy of the results obtained.

When determining the karyotype of the fetus using cord blood cells, any mutations are excluded. Distortion of the analysis results due to placental mosaicism, which is possible with placentobiopsy, chorionic villus sampling or amniocentesis, is also excluded here. Therefore, the analysis can be considered the most accurate of all prenatal invasive diagnostic methods.

The accuracy of the results can be affected by the fact that it is not always possible to obtain pure genetic material of the fetus on the first try - without impurities of the mother’s cells. There are analyzers that determine the purity of the collected blood. They are used to eliminate errors in the results.

In many ways, the accuracy of diagnosis also depends on the qualifications of the doctors performing the operation. When performed technically correctly, the reliability of cordocentesis results reaches 99.9%.

Complications and consequences

Invasive intervention, which is the collection of umbilical cord blood, is a surgical operation, which, like any other, is associated with the risk of developing complications after it is performed. That is why doctors insist on hospitalizing the expectant mother and monitoring her condition and the condition of the fetus for several days after cordocentesis.

Possible consequences:

• the fetal heart rate decreases to 100 beats/min. And in 12% of cases, umbilical cord puncture ends in cardiac arrest in the fetus. The likelihood of developing bradycardia depends on the duration of pregnancy and increases in proportion to it. But most often the baby’s heartbeat is restored without outside intervention;
• Bleeding may occur from the puncture point. Statistically, this happens in half of the cases. But only in 19% the puncture can bleed for more than 1 minute. To avoid this type of complications, blood sampling is done not from the arterial vessel of the umbilical cord, but from the venous one. And for manipulation, needles of the smallest diameter are selected. No special treatment is required here. And minor bleeding at the puncture site does not pose a danger to pregnancy;
• the appearance of hematomas in the area of ​​the umbilical cord puncture is a very rare phenomenon. But it occurs in 0.4% of cases. As practice shows, this complication does not negatively affect the condition of the fetus;
• in approximately 3% of cases, after cordocentesis, expectant mothers develop an inflammatory process - chorioamnionitis. For its prevention and treatment after invasive intervention, the pregnant woman is prescribed a course of antibiotics;
• If a woman has a negative Rh factor in her blood, she is given anti-Rhesus immunoglobulin within 48 hours after surgery. This helps to avoid Rh conflict that may arise as a result of the manipulation;
• in 3% of cases, spontaneous abortion occurs after cordocentesis; the risk of miscarriage increases during pregnancy with twins. Increased uterine tone is the most serious complication. You need to be wary of such developments for another 14 days after the procedure. During this period, it is better for the expectant mother to stay in bed and be under constant medical supervision. And to relieve uterine tone, take tocolytic drugs.

The development of complications after cordocentesis can be influenced by many factors: from professional qualities physicians conducting diagnostics, to the characteristics of the state of pregnancy at the time of blood sampling.

The difference between cordocentesis and amniocentesis

If we talk about which invasive diagnostic method is the most common, then amniocentesis can confidently take the lead.

Amniocentesis involves puncturing the amniotic membrane and collecting amniotic fluid for analysis.

Amniocentesis is a puncture of the amniotic membrane, the purpose of which is to obtain amniotic fluid for analysis. This type of diagnosis is carried out at 14–20 weeks of pregnancy and is considered not so complicated, and also less associated with various kinds risks.

Video “What is amniocentesis?”

When issuing a referral for diagnosis, the geneticist takes into account a number of factors that influence which method will be more preferable in each specific case. There are situations when cordocentesis becomes a priority for all indicators of pregnancy. But there are not many such circumstances.

Table “Cordocentesis or amniocentesis?”

For example, to confirm or refute the presence of fetal malformations that are incompatible with life, a pregnant woman will, of course, be sent for cordocentesis, since not only accuracy is important here, but also the speed of obtaining the result.

After all, if the diagnosis is confirmed, a decision will be made to terminate the pregnancy for medical reasons. And such an operation cannot be postponed in order to avoid complications in the woman.

If the fetal karyotype is determined by other indications, then amniocentesis is often preferred.

Where do they make it, how much does it cost?

Today, cordocentesis is carried out both in antenatal clinics, where the necessary equipment is available, and in private clinics. The procedure will be paid in both cases.

The price ranges from 18–23 thousand rubles. - for residential complexes and 27–28 thousand rubles. - for private clinics and medical centers. It all depends on the status of the chosen medical institution and the qualifications of the specialists performing the operation.

When choosing a clinic where you will have a cord blood puncture, be very responsible. When making a decision, carefully study the statistics of complications for a particular center, read the book of complaints and suggestions, and seek information on forums where expectant mothers share their impressions and reviews.