After taking a chorionic villus biopsy, you can. Chorionic villus sampling - why should you do this test? How to do a biopsy

Everyone wants to have healthy children. Of course, not everything is in the hands of a person, but, nevertheless, it is now possible to find out before the birth of a child, at a fairly early stage, with an almost 100% guarantee whether the child has chromosomal abnormalities, in other words, whether his karyotype is normal.

Karyotype- a set of characteristics (number, size, shape, etc.) of the complete set of chromosomes inherent in the cells of a given biological species.

Normal human karyotypes - 46.XY (male) And 46.XX (female). In cases where a child has chromosomal abnormalities, his karyotype will be different.

Thus, the most famous chromosomal abnormalities - Down syndrome (three 21st chromosomes) correspond to a karyotype 47,ХY, 21+ or 47,ХХ, 21+; Edwards syndrome (three 18th chromosomes) correspond to a karyotype 47,ХY, 18+ or 47,XX, 18+, etc.

The severity of the consequences for the health of the child for different anomalies also differs - there are both severe anomalies that simply lead to arbitrary termination of pregnancy in the early stages, and relatively “mild” and “viable” ones - for example, Down syndrome.

It is worth noting that chromosomal diseases do not depend in any way on the lifestyle of the parents - these are mutations that arise spontaneously and can be predicted no way(with the exception of a very small percentage (3-5%) of chromosomal abnormalities that are inherited and usually known in the family).

That is why a healthy lifestyle and the absence of relatives with chromosomal diseases, for example, does not guarantee the absence of an anomaly in the unborn child in this particular family.

There are several methods to find out in advance, during pregnancy, whether the baby has problems with chromosomes. For the reasons described below, I chose for myself chorionic villus biopsy. The main reason is a 99% guarantee of result accuracy.

Chorionic villus biopsy- obtaining a sample of chorion tissue (future placenta) in order to identify chromosomal diseases and the carriage of chromosomal abnormalities. Chorionic tissue basically has the same genetic structure as the fetus, and is therefore suitable for genetic diagnosis.

Chorionic tissue is obtained by puncturing the uterus through the anterior abdominal wall with a catheter.

Why chorionic villus biopsy, if it is so accurate, isn’t it prescribed to all pregnant women? Because this is an invasive method (sampling of material is required) and it has a certain percentage of complications - the likelihood of termination of pregnancy: to 2% .

In Russia, pregnant women are required to undergo only prenatal screening; it consists of an ultrasound and a blood test for hormones: hCG and PAPP-A. Neither ultrasound results nor hormones provide grounds for diagnosing chromosomal disorders in a child. They only show risk, that is, the likelihood of these violations.

But in practice, there may be a perfect ultrasound and a perfect blood test - but a sick child is born. And, on the contrary, according to ultrasound and blood everything is bad - but the child has a normal karyotype. The frequency of errors and discrepancies is so high that I would put classical prenatal screening on a par with fortune telling on coffee grounds and weather forecasting.

But, since one of the traits of a Russian person is hope for chance, multiplied by scary stories about an obligatory miscarriage after a abdominal puncture and stories from girlfriends who have already given birth to healthy children that: “Is it dangerous, don’t even think about a puncture, you see, “I (Masha, Dasha, Glasha) are doing well” - all this only leads to the fact that women are afraid of invasive diagnostics like fire and write a lot of refusals, even after receiving poor results of prenatal screening.

During my first pregnancy, I did not do invasive diagnostics - I was young and stupid. I was lucky - everything was fine with the child’s chromosomes (the blood screening, by the way, was bad and I refused a puncture from a geneticist). However, having immersed myself in the topic of children, looking at deeply sick children, a 21-year-old girl I knew who gave birth to a son with Down syndrome after good screening, and having matured, I came to my second pregnancy with a firm thought about what I would do chorionic villus biopsy in any case. Of course, it is impossible to protect a child from everything, but, nevertheless, it is completely possible to exclude damage to his chromosomes. And this is within my power.

It is worth noting here that the reaction to my desire to voluntarily chorionic villus biopsy, or, who found out about this after the procedure from a variety of doctors, from a gynecologist to a geneticist and ultrasound specialists, it was absolutely identical. First, a surprised face, then they asked me again, “Voluntarily??”, and then there was praise for responsibility and recognition that either the doctor himself, or his wife/daughter, and all colleagues performed this procedure on themselves during pregnancy absolutely without any indications, if desired. And here the doctors can be understood - they do not have rose-colored glasses, they have seen and heard a lot, alas.

But, closer to the procedure itself chorionic villus biopsy. After visiting a geneticist, I received a list of tests that needed to be taken:

In terms of preparation: two days before the puncture, insert papaverine at night. On the advice of the gynecologist, I inserted it within three days after the procedure. My obstetric period on the day of the procedure was 13 weeks ( chorionic villus biopsy do up to 14 weeks).

On the appointed day, I showed up at the clinic in the morning and took a room for the day. This is important - after the puncture you need to lie down, everything should be in a very calm, snail-like mode.

After signing the papers, I went up to the office. Actually, the procedure itself is performed by two doctors: an ultrasound specialist and a functional diagnostics doctor who collects the material. Having undressed from the waist down, I lay down on the table. The ultrasound specialist found the child with a sensor, and together with the second doctor they determined the place where the needle should be inserted. After that, they gave me an anesthetic injection in the stomach (it didn’t hurt, but I didn’t understand the effect from it).

After waiting time for the injection to take effect, the ultrasound sensor again found the child, and the second doctor began inserting a needle into the lower abdomen and drawing material into the syringe. Everything is under continuous ultrasound control. It lasted 15-20 seconds, and it was painful, more painful than a regular injection, but nevertheless it ended quite quickly. After this, they again monitored the child’s heartbeat with an ultrasound sensor, taped the belly with a plaster and sent him to the ward to rest.

My stomach felt like I was on my period, but it went away after about half an hour. I inserted papaverine. Exactly an hour later, I went for a control ultrasound, which showed that everything was fine with the child, and went back to the ward to lie in bed until the evening. After getting some sleep, taking off the bandage, I went home in the evening. There was a small mark left, as if from an injection, and it healed quickly.

Then, of course, there was a week of waiting for the results and, finally, a call from the geneticist: you have a healthy boy. You can breathe out.

So, the reasons why I decided to do chorionic villus biopsy:

• A genetic analysis of the fetus itself (chorion - the future placenta) is carried out, and not of hormones in the mother’s blood. This is similar to the fact that a person who has already been born is tested for his karyotype. Confidence 99%.
• Invasive methods are the last resort for us. If the ultrasound and prenatal screening data are very bad, before terminating the pregnancy, invasive diagnostics are still first done to confirm.
• There is an analogue chorionic villus biopsy- a non-invasive test where the child's DNA is taken from the mother's blood. But, in case of a bad result, you will not have an abortion, but, again, will be offered invasive diagnostics to confirm. In addition, the cost of a non-invasive test is currently very high (in our city from 40,000), and the guarantee is still less than that of chorionic villus biopsy.
• As for the risk of spontaneous abortion after a biopsy, it is 2%. Here my personal opinion is this: if after chorionic villus biopsy If a miscarriage occurs, it is a question of fetal viability. Most likely, the interruption would have happened anyway.

UPDATE. I did not have any complications after chorionic villus sampling. At gestational age 38+5, I gave birth to a healthy boy weighing almost 4 kg (planned CS).

● ● ● ● ● ● ● ● Sincerely, Lisiya ● ● ● ● ● ● ● ●

P.S. My reviews on the topic of pregnancy and conception:

• Ovulation test showing 4 days in advance - Clearblue ADVANCED DIGITAL Ovulation Test
• All-natural vitamins Innate Response Formulas Baby & Me Trimester I & II for planning and pregnant women

Chorionic villus sampling is a prenatal test performed during pregnancy to identify possible abnormalities in the development of the fetus. You can take it if the information you receive helps you make an important decision.

Things to remember about this test:

• It is carried out in the first trimester of pregnancy. If the doctor diagnoses a serious abnormality, you will have time to prepare for the birth of a child with a pathology or decide to terminate the pregnancy. If the result is negative, this will allow you to worry less.
• Using this procedure, you can determine the presence of many diseases and defects, including Down syndrome. However, remember that the answer you receive is not always absolutely correct. No test will give you a 100% guarantee that the child will be born completely healthy.
• Chorionic villus sampling does not detect a neural tube defect, such as congenital spina bifida. If you are concerned about developing this particular disease, you can undergo amniocentesis instead of this test. Or, after a chorionic villus biopsy, do an additional blood test to determine the problem.
• This test is not a routine safe procedure as it carries a (small) risk of miscarriage. For example, if 400 women undergo it, 1-4 of them may have a spontaneous abortion after the test. You have the right to decide whether the information received is worth the life of your unborn child.
• This procedure is quite expensive. Many insurance companies cover these costs for women over 35 years of age. If you do not belong to this category, and the price is unacceptable for you, you can always choose an alternative test.

Medical information

Chorionic villus biopsy - what is it?

This is a test that allows you to identify abnormalities in fetal development. It is usually performed at the end of the first trimester, between the 10th and 12th weeks of pregnancy.

Chorionic villus sampling helps diagnose:

• Congenital defects associated with abnormalities at the chromosomal level, for example, Down syndrome.
• Many hereditary diseases, such as early childhood amaurotic idiocy and hemophilia.

Since this test does not detect a neural tube defect (for example, congenital spina bifida), it is recommended to additionally do a blood test for alpha-fetoprotein. The latter is carried out at 16-18 weeks of pregnancy.

Chorionic villus biopsy - how to treat this test?

You should undergo this procedure if:

• A screening test carried out in the first trimester established that there is a possibility of the fetus developing Down syndrome (This is an ultrasound of the fetal neck (for the transparency of the cervical fold) and a blood test of the mother).
• You are over 35 years old. This age of the mother increases the risk of the child developing Down syndrome. The older the woman, the greater the likelihood that the baby will develop such an anomaly. In 1 case out of 350, a pregnant woman over 35 years old gives birth to a child with the above-mentioned defect. If the mother is 40, 1 in 100 children is at risk of being born with Down syndrome. Parents (together or one of them) may be carriers of a hereditary family disease (genetic disorder), for example, early childhood amaurotic idiocy, sickle cell disease or abnormalities in the development of chromosomes, which they will pass on to the child.
• You may have medical reasons why you need to determine the sex of your unborn baby. This need is most often due to the fact that one of the parents is a carrier of a disease that causes abnormalities in the development of sex, for example, Duchenne muscular dystrophy or hemophilia. Both of these diseases occur predominantly in men.
• You already have a child with Down syndrome or another chromosomal defect.
• An ultrasound showed that the fetus was predisposed to developing a birth defect.

Chorionic villus sampling - how is this test performed?

To perform this test, a sample of chorionic villi cells is taken and examined for defects. Chorionic villi are small finger-shaped projections that are found in the placenta. The genetic material of these villi is identical to that of the fetus.

The doctor can collect the sample in two ways:

• Passes a flexible tube (probe) through the vagina and cervix into the placenta (transcervical chorionic villus sampling).
• A thin, long needle passes through the abdominal cavity and enters the placenta (abdominal chorionic villus sampling). This procedure is similar to a puncture of the amniotic sac.

Ultrasound is used to guide the probe or needle to the desired part of the body.

Chorionic villus biopsy - how to perceive the test results?

A negative test result will confirm that the fetus does not have developmental abnormalities at the chromosomal or gene level. This is certainly a good indicator, however, remember that no one procedure can eliminate the occurrence of health problems or guarantee that the baby will be born completely healthy.

If it is confirmed that the fetus is developing a serious illness, you will have time to think it over and decide what to do next. In some cases, it depends on various factors, for example, on the type of defect or your personal reaction. Depending on this, you may have the following thoughts:

• Should I continue the pregnancy? If a serious defect is detected in the fetus, some women decide to terminate the pregnancy (medical abortion) during the first trimester. Others simply need time to prepare themselves and their loved ones for the birth of a baby with a defect.
• Where is the best place to give birth? If a defect is detected in the fetus that requires surgical intervention at birth, the best option would be to give birth in a specialized clinic that provides this type of service.
• What is better for a child with such a deviation: vaginal birth or cesarean section?

Chorionic villus biopsy - a possible risk during the test

This procedure increases the risk of:

• Infection in the uterus.
• Miscarriage. Some studies have shown that when the procedure is performed by an experienced specialist, the risk of spontaneous abortion is 1 in 400 cases. Others say the risk is higher (2 to 4 out of 400 cases). The likelihood of this type of consequence increases if the test is performed by an insufficiently qualified doctor.

This test virtually eliminates the possibility of mixing the blood of the mother and fetus. If you are Rh negative, you will be given a vaccine before the procedure to prevent Rh sensitization.

Chorionic villus biopsy - what happens if you ignore the prescribed procedure?

If you don't get a chorionic villus sampling or other prenatal diagnostic test, you risk giving birth to a baby with an unsuspected birth defect or Down syndrome. The risk is as follows:

• The birth of a child in this case becomes a risk group, since the doctor does not know about possible congenital pathologies.
• You may give birth in a hospital that does not have a neonatal intensive care unit for sick or premature babies.
• Most parents are not mentally prepared for the birth of a child with a serious illness or congenital defect.

Consult your healthcare provider about any necessary tests. Additional tests can also reveal the presence of a genetic disease.

Chorionic villus fiber biopsy - is there a similar test?

As an alternative, you may consider amniocentesis, which can be done in the second trimester of pregnancy. It is used to diagnose more than 100 different hereditary diseases, such as Down syndrome and neural tube defect. To do this, the doctor passes a needle through the pregnant woman's abdomen and into the uterus, where she takes a sample of amniotic fluid. To obtain reliable genetic information, amniocentnesis must be done at 15-20 weeks of pregnancy, when there is already enough amniotic fluid for research.

Comparative characteristics of chorionic villus biopsy and amniocentesis:

• Chorionic villus sampling can be performed earlier in pregnancy than amniocentesis. This will give more time to make a decision and reduce the mother’s anxiety about the safe development of the fetus. If you decide to terminate your pregnancy, this procedure will be safer in the first trimester.
• Chorionic villus sampling does not reveal a neural tube defect. Therefore, in the second trimester of pregnancy, you should take a blood test to determine the level of risk of the fetus developing this defect. If the result is positive, the doctor will perform an ultrasound of the fetus.
• Preparing the results of a chorionic villus biopsy takes a week, while the answer after amniocentesis will have to wait from 2 weeks to a month.
• If both tests are carried out by qualified professionals, the risk of a possible miscarriage is reduced to a minimum. One study shows 1 in 400 cases, others - 2 and 4 cases in 400. The likelihood of this type of outcome increases if the test is performed by an insufficiently experienced doctor.
• Chorionic villus biopsy is not performed in all clinics. This requires special qualifications and, in addition, the procedure itself is more complex than amniocentesis.

You have the right to decide to undergo another test, for example, amniocentesis, or simply refuse genetic testing.

The decision to have a chorionic villus sampling is influenced by both your personal feelings and your doctor's orders.

Young and mature pregnant women often undergo various tests. This helps doctors correctly guide the mother to a normal birth of the baby. You can often hear how a gynecologist refers women in labor to a chorionic villus biopsy. This operation has a low risk of complications. It is much more dangerous if the child is sick.

What is the technique

Chorionic villus biopsy is a test performed before childbirth to identify genetic disorders in the fetus. For this purpose, biological tissue is taken - the placenta.

The specialist analyzes it and makes a diagnosis of the presence or absence of chromosomal abnormalities.

This analysis is similar to when amniotic fluid is taken for study, it is called. You can carry it out and get an accurate result much earlier.

Indications for the study

What is chorionic villus sampling? This is a method of penetration through the natural tissues of the body, that is, it is quite unsafe.

Complications can always arise during the process, so doctors take into account the need for the procedure in each specific case.

There are absolute indications for this:

• primiparous woman in labor. This age is most susceptible to the birth of children with pathologies;
• if there are already children with genetic diseases or these were previously identified during pregnancy, for example Down Syndrome;
• when a child in the family has intrauterine anomalies;
• parents have or already have hereditary diseases;
• the examination revealed signs of development with defects;
• If the transmission of a hereditary disease is possible only by gender, the gender of the child is determined.

Consequences of chorionic villus sampling may occur, but after 35 years this risk is justified. This is the age when the likelihood of genetic pathologies increases.

Statistics indicate that out of 700 late births, 1 case has an intrauterine developmental defect. It is associated specifically with changes in cells at the chromosome level.

With this diagnosis in the early stages of pregnancy, parents can independently decide to continue carrying the baby or have an abortion.

But, despite the effectiveness and information content, the chorion sampling technique does not detect pathologies of the neural tube. This is due to the fact that the nervous system develops at 20 weeks of pregnancy, and this diagnosis is carried out much earlier.

In the third trimester, different material is taken for research.

Important! If you refuse to conduct research, taking into account the fact that you have special indicators for this, then you are putting your health, the process of normal childbirth and the life of the baby at risk. A child may be born with a defect that is incompatible with normal existence. Many parents are morally unprepared to raise sick children.

How is the operation performed?

In order to identify this or that pathology using this method, it is necessary to take into account at what time the chorionic villus biopsy is performed. Since this method is impossible to carry out in later stages.

For safety and effectiveness, the thickness of the chorion should not be less than 1 cm.

If a biopsy is performed early, there is a risk of complications and impaired development of the fetal limbs.

In the later stages, it is already formed, so the procedure cannot be performed.

The most optimal period for diagnosis is 10-12 weeks.

There are various techniques, this is due to the place where the placenta is formed. Penetration is possible through the anterior wall of the abdomen or through the uterus.

The first option is much safer. However, if the placenta develops on the posterior uterine wall, then it is impossible to take the material using the first method.

There is also a difference between single-needle and double-needle methods.

Abdominal surgery is performed under ultrasound guidance. The puncture site must be treated against infection; anesthesia is not used, since there is no pain.

The single-needle technique is performed with one needle. By piercing the tool gradually makes its way to the desired location.

The mandrel to which the needle was attached is removed, a syringe with the required amount of nutrient medium is placed on it, and the material is taken away.

In the two-needle technique, one serves as a guide and the other for biopsy.

The collection is performed through the uterus if the membranes are located on the posterior wall. The operation is performed on a gynecological chair. The woman is positioned as during a normal examination.

The vaginal and uterine walls are fixed with forceps, then a catheter is inserted. Observing on the monitor, under ultrasound diagnostics it is brought to the desired place.

The mandrin is removed, and a syringe with the drug is put on the tube. The material is collected.

When a woman is carrying two fetuses, the procedure is the same as if she has one. But the material is taken from each of the embryos. It is important to determine and not confuse the results of one and the other.

In the laboratory, the taken material is processed and studied. For accuracy, it is very important that enough cells to be studied are taken.

We must not allow the maternal staff to get there. Repeated analysis does not eliminate the same risks.

Due to the fact that the cells take a long time to open, the result will be no earlier than in 2 weeks.

With the help of artificial cultivation, which is carried out in private clinics, the time required to receive an answer can be reduced.

Many are also interested in when it is possible to become pregnant after a chorionic villus biopsy, if according to indications the woman was forced to have an abortion.

In this case, the subsequent resolution of conception is influenced not by the procedure itself, but by the reasons why the genetic failure occurred.

It may be necessary to restore or treat the body a little in order to avoid subsequent diseases.

Safety of the procedure

There is a lot of information that taking material in this way affects the development of limb pathology. However, researchers have proven that anomalies appear only when the procedure was performed at a dangerous stage - less than 10 weeks of pregnancy.

To protect yourself, consult a specialist. Perhaps in your case it is not worth exposing yourself to the threat, and the risk of deviation is not so great.

No one can guarantee the safety of the operation. In practice, the most unpredictable consequences incompatible with the life of the fetus have occurred.

Important! Considering all the possible disadvantages of the procedure, the poor health of the mother after the biopsy must be verified as to the presence or absence of anomalies. This will help determine next steps.

Possible consequences for pregnancy

After the procedure, it is possible to observe different reactions. Some are completely natural and do not pose a risk for further pregnancy. Others have consequences.

Pain in the lower abdomen reminiscent of menstruation, small spotting, and small bruises are a normal reaction.

Severe hemorrhage leads to miscarriage. In rare cases, an infection can occur if safety and hygiene measures are not followed.

An unqualified specialist can disrupt the integrity of the membranes.

Sexual characteristics

Chorionic villus biopsy to determine the sex of the child is performed only in selected cases. Because this is not the safest way.

Under existing indications, transmission of a genetic disease is limited to a specific gender.

For example, adrenogenital syndrome, it is characterized by the absence of menstruation and mammary glands.

What the test results will show

Based on the taken genetic material, an image of all chromosomes is created in the order of the diploid set of the cell.

Thus, all violations in the number of chromosomes become visible. That is, perhaps there are more or less of them than expected. The sex of the child is also determined.

The reason for a fetal biopsy is to find out these changes.

Preliminary results are known within 2 days, but you will receive a final answer no earlier than 10 days.

Since this procedure is a kind of stress for a pregnant woman, after it it is necessary to limit yourself from any stress.

It is better to be under the supervision of a doctor, as postoperative reactions are often observed. Minor bleeding. In addition, fluid may leak with blood, which is not the norm. In this case, the gynecologist must take rehabilitation measures.

Video: what is chorionic villus biopsy

Having heard from a gynecologist at the antenatal clinic about the need to undergo a chorionic villus biopsy, a pregnant woman is very scared. But in fact, this procedure is practiced all over the world and has a very small percentage of possible complications.

What is it? Chorionic villus sampling is a test that involves obtaining a small sample of tissue (chorionic villi) from the developing placenta. The thing is that the placenta has the same genetic material as the child, so this method of checking for the presence of Down syndrome, cystic fibrosis, genetic, DNA and biochemical abnormalities is the most appropriate and safe.

Who is offered to do this procedure?

Women who are at high risk of having a child with Down syndrome or other chromosomal abnormalities. This category includes pregnant women who

• age exceeded 35 years;
• on an ultrasound scan at 12-14 weeks of pregnancy, the fetal nuchal translucency thickness (thickness of the nuchal translucency) exceeded the norm;
• there was already a fact of pregnancy with a child with chromosomal abnormalities.

Chorionic villus sampling cannot confirm spina bifida in the fetus. However, another scan can be done at 18 weeks, when many physical abnormalities can already be detected, including this abnormality.

Important details

How is the procedure done? Doesn't it hurt?

To begin with, the skin in the lower abdomen is treated with an antiseptic solution. After this, local anesthesia is given, which makes the procedure absolutely painless. Some women claim that it is comparable to a blood test from a vein.

Under ultrasound guidance, a thin needle is directed into the placenta and a small amount of chorionic villi is taken. At this point, women may feel slight discomfort in the lower abdomen or leg, but there will be no pain.

In rare cases, more than one biopsy may be necessary to obtain enough tissue for analysis.

Deadlines

The ideal period for this procedure is 11-12 weeks of pregnancy. But it can also be performed starting from 9 weeks and 3 days until the end of the 19th week.

What tests need to be done before the procedure?

1. Ultrasound. You need to come for a biopsy with a full bladder, so that before taking tissue, an ultrasound can be performed to make sure that the fetus is alive and healthy, confirm the number of fetuses, and check for abnormalities in the child.
2. You must provide information about your blood type and Rh factor. If your Rh factor is negative, you may need to have an injection after the biopsy.

What happens after?

The sample is taken to the laboratory and processed. The tissue is placed in a certain environment and then in an incubator for several days. When there are enough dividing cells, they are taken out of the incubator and broken down by an enzyme.

Individual chromosomes are then counted and a thorough analysis is carried out for major and rare genetic abnormalities.

What should you do after the procedure?

Most women experience mild abdominal and leg cramps after the biopsy. These unpleasant sensations will begin immediately after the local anesthesia wears off (about half an hour after the procedure).

Sometimes slight bleeding may appear. This is also considered normal.

What are the risks and consequences?

There is a 1% chance of miscarriage. As a rule, this is due to an infection that nevertheless penetrated as a result of the procedure. Specialists take all precautions to avoid this. : Severe pain and bleeding that usually begins between 24-48 hours and 1 week after the test.

There are also additional complications:

• destruction of the chorionic villus sample in the laboratory;
• test results remained indeterminate.

This happens very rarely, but everything happens. In this case, the woman will be offered to have it done at 15-16 weeks. This test provides the same information as a chorionic villus sampling.

Chorionic villus biopsy is a research method in which embryonic tissue cells are collected for further cytogenetic and biochemical analysis. This procedure is carried out only if there are serious indications during certain periods of pregnancy.

Why is the procedure performed?

The chorion is an extra-embryonic outer membrane, which from the end of the first trimester begins to transform into the placenta. It is necessary to separate the embryo from the tissues of the uterine wall, to protect the fetus from toxins and pathogenic microorganisms, and for normal metabolism between the maternal and child's body.

Carried out under ultrasound control

Chorionic tissues are formed from embryonic cells, so they have the same genetic material as the embryo. The collection of chorion cells does not have a negative impact on the further development of the fetus, therefore the study of the obtained tissues is the safest and most informative method of prenatal diagnosis.

Through this analysis, it is possible to detect about 3,800 diseases in the fetus associated with genetic disorders. With its help, you can identify the following groups of diseases:

• chromosomal structure disorders - Down syndrome, Patau syndrome and others;
• enzymopathies – phenylketonuria, citrullinemia and others;
• hemoglobinopathies;
• lysosomal storage diseases - metabolic disorders of carbohydrates, glycoproteins, glycosaminoglycans.

The results obtained have a high degree of reliability. They may be incorrect if the biopsy sample contains endometrial tissue in addition to chorionic villi. Errors are observed in approximately 4% of cases.

Indications and contraindications for the procedure

Such a study is invasive, so it is prescribed when non-invasive methods do not provide the necessary information. Also, indications for chorionic biopsy are:

• presence in the family of carriers of diseases transmitted by inheritance;
• poor results of the first prenatal screening, showing a high probability of developing chromosomal diseases in the fetus;
• stillbirth, death of a child in the first days after birth, or the birth of a baby with genetic abnormalities before the onset of the current pregnancy;
• woman's age over 35 years. At this age, spontaneous critical mutations may occur.

The procedure is prohibited if there are contraindications, since it creates a threat of spontaneous miscarriage, promotes infectious diseases, fever, and exacerbation of chronic diseases.

The decision to conduct such an analysis is made by a medical commission. The woman must give her consent.

Timing of the procedure

The test can be scheduled at 10–13 weeks of pregnancy. At this time, the embryo already has organs and organ systems, but the placenta has not yet fully formed.

It is not recommended to perform a biopsy earlier, as this may lead to miscarriage. By the end of the first trimester, the transformation of the chorion into the placenta begins. In the future, you can take a sample for research, but this will be a biopsy of the placenta - placentocentesis.

The timing of chorionic villus biopsy is 10–13 weeks of pregnancy

How is a biopsy done?

Before the study, a woman must undergo a comprehensive examination, which includes a general blood and urine test, a vaginal smear for microflora, ultrasound and other studies.

Before performing a biopsy, the doctor examines the uterine cavity of the pregnant woman, assesses its condition and the position of the embryo. There is no anesthesia before the procedure, but the woman may be prescribed pain relief to relieve discomfort.

During the entire process, the position of the puncture needle is monitored using ultrasound. For better visibility, a woman is recommended to drink 2-3 glasses of liquid an hour before the examination. Due to this, the bladder will fill and begin to compress the uterus, which will improve its visualization on ultrasound.

Transabdominal biopsy, in which material is taken through the abdominal wall, includes the following steps.

1. The area of ​​skin on the abdomen through which the puncture will be performed is treated with an antiseptic.
2. The anterior abdominal wall and uterus are punctured until the needle reaches the myometrium.
3. The needle position is adjustable. It should be parallel to the chorionic membrane.
4. The puncture needle is immersed in the chorionic tissue. A syringe is attached to the outer contour of the needle, into which a sample of material is sucked. A two-needle technique can be used. A needle of smaller diameter is immersed into the chorion, and the second one is a guide needle. The minimum amount of biopsy obtained should be 5 mg, and the optimal amount should be 10–15 mg.
5. The needle is removed and the puncture site is treated with an antiseptic. An antiseptic bandage is applied.
6. An ultrasound scan is performed to monitor the condition of the uterine wall and the baby’s heartbeat.

A transcervical biopsy through the cervical canal may also be performed. In this case, the integrity of the uterine cavity is not violated. A flexible thin catheter with a mandrel is used. Its tip is inserted into the chorion under continuous ultrasound control.

The entire procedure usually lasts about half an hour. If the chorion is located on the lateral uterine walls, access to it may be difficult. Therefore, the duration of the biopsy may increase.

To obtain more reliable results, several methods can be combined at once - for example, chorionic villus biopsy and amniocentesis. This is also an invasive procedure in which amniotic fluid is collected and examined. Using this method, you can obtain data on fetal development anomalies and infection of amniotic fluid.

For biopsy, a thin catheter with a mandrel is used

Biopsy results

The results of the study are known in 10–14 days. Before receiving them, the woman is prescribed preventive treatment necessary to maintain pregnancy. It is also recommended to reduce physical activity, avoid carrying heavy objects, and avoid sexual intercourse.

If the test results are negative, the woman can continue to carry the fetus as it develops normally. But if any abnormalities are detected, the pregnant woman is faced with a choice - to terminate or continue the pregnancy. If a woman refuses an abortion, it is necessary to determine in advance the place of delivery and draw up a plan for the management of the newborn.

Possible complications

Since the procedure is invasive, there is a risk of complications:

• miscarriage. It can happen 5–7 days after the procedure;
• bleeding from the vagina. They can appear due to damage to the chorion and injury to the cervix. Bleeding is observed in about a quarter of women after the procedure. Light discharge goes away on its own as the wound heals. But if the bleeding is quite severe, you should immediately consult a doctor to prevent abortion;
• retrochorial hematoma. Its occurrence increases the likelihood of abortion. However, it may resolve on its own by the end of the 4th month of pregnancy. The hematoma does not affect the development of the fetus. But it can break into the uterine cavity, which will lead to light brownish discharge from the vagina;
• Chorioamnionitis. This is a fairly rare complication of chorionic villus sampling. The fetal membranes become inflamed and the amniotic fluid becomes infected;
• damage to the membranes of the fetus. This can lead to leakage of amniotic fluid, which can lead to an infectious process;
• congenital amputations of limbs. This can happen due to the biopsy being performed very early in pregnancy - before the 10th week. Atrophic changes may begin in the area of ​​intervention. This complication does not appear if the procedure is carried out within the permitted time frame;
• alloimmune cytopenia in a child. This complication can occur if there is a Rh conflict during pregnancy. Therefore, it is recommended to administer anti-Rhesus immunoglobulin to all women with a negative Rh factor if the father is positive. It is advisable to administer the drug within 24 hours after chorionic villus biopsy.

Such complications are observed only in 4–5% of cases. To avoid their occurrence, you need to contact a qualified specialist with extensive experience and take into account all contraindications.

Chorionic villus biopsy is a very informative prenatal study. But it is prescribed only if there are serious indications, since the likelihood of complications developing is quite high.