home Consultations How an ultrasound is done in the early stages. The principle of assessing the vital activity of the fetus and embryo. What does ultrasound show during early pregnancy?

How an ultrasound is done in the early stages. The principle of assessing the vital activity of the fetus and embryo. What does ultrasound show during early pregnancy?

During pregnancy, every woman undergoes a systematic examination, which helps monitor the growth and development of the fetus. At the heart of obstetrics and gynecology, the main thing is to create all the conditions for a woman in labor reproductive age, which are aimed at the full course of pregnancy, the growth and development of the child. For this purpose, delivery is assigned laboratory tests, routine examinations, and ultrasound, which allows you to diagnose the baby’s condition or possible complications.

First ultrasonography in a normal pregnancy, it is prescribed at 9–11 weeks. If complications or pathologies of the fetus are suspected, an ultrasound scan is performed earlier. Exists a large number of myths about the harmfulness of ultrasound waves, but this research method has been carried out for more than 70 years, and during this time it has helped prevent complications or abnormalities of pregnancy, therefore ultrasound is considered the most informative and safe method of examination, even in a short period.

Ultrasound examination will help prepare for upcoming birth and provide an opportunity to monitor the characteristics and development of the baby. Ultrasound on early stages will help determine the following features:

presence of pregnancy - visualization ovum in the uterine cavity can be noticed at 3 - 5 weeks, or after the last menstruation, when the egg is 2 - 3 mm.
Exact period - at this stage, the size of the embryo is determined using the method of the size of the fetal sac, which corresponds to the days after the missed period. Very often, the doctor can make a mistake by 1 - 2 weeks.
localization of the fertilized egg - helps to determine the intrauterine or ectopic pregnancy, which is determined within 7–10 days after a missed period.
Number of embryos - a multiple pregnancy is detected at 5 - 6 weeks, when two or more fetal sacs are observed, whereas in a singleton pregnancy there is only one fetal sac.
The viability of the embryo is confirmed.
The functionality of the embryo's heart is determined at 3–4 weeks and is displayed on the monitor screen. At this moment, the mother can feel the first heartbeat, this also allows the doctor to make sure that the embryo is alive.
in the early stages it is very difficult, and only experienced doctor with many years of experience will be able to determine gender by external signs at 12 - 13 weeks.

The condition of the cervix is also assessed, which under normal circumstances should be normal. Any disturbance in the uterus can cause miscarriage or complications.

Ultrasound of a pregnant woman with suspected pathology

In the early stages of pregnancy, suspicion of pathological processes, especially if the mother has a history of severe genetic diseases, internal infections that can cause complications during the development of the fetus, or lead to disability of the unborn baby.

In such cases, ultrasound is considered necessary method examination, which can prevent anomalies and give the woman the opportunity to decide and decide later life future child. The most common pathologies that ultrasound can detect in the early stages are:

Threat of miscarriage - if there is a suspicion of a threat of miscarriage, bloody clots very often form in the uterus, or placental abruption occurs, which can provoke a short-term miscarriage. Ultrasound examination will help detect violations and proper treatment keep the pregnancy.
Identify diseases of the pelvic organs that can negatively affect the condition of the fetus.
Developmental pathologies are diagnosed at the end of the first trimester. Ultrasound can detect such pathologies in the fetus as: heart defects, Down syndrome, underdevelopment, as well as some hereditary diseases and others who are capable of providing the child with disability for life. Women in labor with suspected pathologies often undergo examinations that will help monitor the growth and development of the baby.
At the end of the first trimester, the doctor can detect gestosis in pregnant women, which is also very dangerous for the pregnant woman.
A frozen pregnancy occurs without any special symptoms and is characterized by a miscarriage that does not take place. In such cases, surgery is performed.
Chromosomal abnormalities, uterine hypertonicity, chorionic detachment and others.

Types of ultrasound during pregnancy

In the early stages, ultrasound diagnostics can be carried out using two methods; there is also modern equipment that allows you to accurately determine all the features.

Ultrasound through the abdominal wall - ultrasound scanning makes it possible to assess the development of the fetus and the course of pregnancy in the earliest stages. The most common is ultrasound through the wall of the lower abdomen, when a special substance is applied to the skin, which helps to more thoroughly examine the internal organs. With the help of an abdominal sensor, the flow of high purity waves is improved, as a result of which the data is scanned onto a computer monitor and the doctor can carefully examine the child and pelvic organs in the early stages.
pregnant woman - the research method is carried out using a vaginal sensor, which is capable of displaying the results on a monitor screen. This examination method gives more accurate results and is able to identify any pathological processes or diseases in the early stages. Before this procedure bladder should be empty, this will make it possible to obtain more accurate results.
3D or 4D ultrasound is a research method that is more often used in modern clinics equipped with special equipment. This method The examination allows you to create examination results in a three-dimensional image from different angles and obtain a clear picture even in the early stages.

Advantages of the first ultrasound

After the first ultrasound examination, the pregnant woman receives the first official document, which contains all necessary information about the condition of the fetus, internal organs and its development.

The research protocol contains data on the number of embryos, its presentation, head size, heart contraction, and also indicates the gestational age, body weight and other information. In cases of deviations or violations, they are also recorded in this document.

Indications for ultrasound in the early stages

After the woman is registered, the attending physician keeps a chart of the pregnant woman, in which he collects anamnesis about previous diseases, hereditary factors, possible miscarriages or other disorders in the body. If a woman has a history of internal or chronic diseases, which can cause fetal abnormalities, then to the expectant mother Ultrasound is mandatory. Particular attention is paid to such pathological processes.

Chronic diseases: diabetes, diseases circulatory system, diseases nervous system, of cardio-vascular system;
A woman’s history of failure to carry a pregnancy to term, fetal loss, miscarriages, abnormal phenomena, when the first child was born with pathologies or abnormalities;
In the presence of oncological diseases or for diseases of the pelvic organs;
Prolonged and severe toxicosis and other pathological processes in which the doctor may have doubts.

How to prepare for an ultrasound

Ultrasound diagnostics does not require special preparation for a pregnant woman. Particular attention should be paid emotional state and not worry about the harmfulness of the procedure. Many experts are sure that the woman is worried because ultrasonic waves can harm the baby in the short term, as a result of which stress hormones are produced in her body, which are transmitted to the child. Therefore, very often during ultrasound there is active movement of the fetus, which sometimes interferes with the procedure.

During pregnancy, which has a normal course, ultrasound is recommended to be performed 2-3 times; in cases of complications, studies are prescribed individually for each woman.

Before choosing a clinic where an ultrasound examination is performed, you should pay attention to the equipment and the doctor, who should have extensive experience in this field of diagnostics.

It is recognized as the most informative and absolutely safe method of monitoring the course of pregnancy. This procedure allows even at a period of 5 weeks - doctors see a formed fertilized egg, and at 6 weeks - a full-fledged embryo.

Deadlines

Throughout the entire period of bearing a child, a woman is prescribed an ultrasound examination three times at precisely specified times:

10-14 weeks;
20-24 weeks;
30-34 weeks.

Despite the fact that the safety of ultrasound examination has been confirmed, gynecologists do not recommend getting carried away with this procedure - it is advisable for pregnant women to undergo it no more than 4 times during the entire period of pregnancy, although additional visits to an ultrasound diagnostician may be prescribed.

What does ultrasound show during early pregnancy?

Women can undergo two types of ultrasound:

Transabdominal. In this case, the patient must prepare for the procedure - 30 minutes before it begins, she must drink about half a liter of water (still) and not visit the toilet. That is, the ultrasound examination procedure is performed with a full bladder.
. This type of examination is carried out without any preliminary preparation; the bladder must be empty. The sensor from the ultrasound machine is inserted into the vagina, after which a special cover or condom with gel is applied to it.

The ultrasound examination procedure in the 1st trimester of pregnancy lasts a maximum of 30 minutes, the doctor takes all the necessary measurements, records the data obtained in a protocol - this document will help the gynecologist determine how normal the pregnancy is and whether the fetus is developing correctly.

Considered diagnostic procedure in the first trimester of pregnancy it is carried out for:

determining the location of the fertilized egg - may develop normal pregnancy, and maybe the formation/fixation of the fertilized egg in the fallopian tubes;
diagnosing a multiple pregnancy, if the doctor sees only the bottom of the ovum, then a singleton pregnancy is diagnosed;
assessing the structure of the embryo, the size of the fertilized egg;
identifying pregnancy problems - for example, a specialist will pay attention to, can diagnose reversible or irreversible spontaneous abortion or.

In addition, ultrasound examination in the early stages of pregnancy allows not only to record the fact of conception, but also to identify various diseases internal genital organs - for example, it is with the help of ultrasound that tumor formations in the ovaries are most often diagnosed, a septum inside the uterus or the bicornuity of this hollow organ is identified.

Interpretation of ultrasound of the 1st trimester: norms and deviations

Ultrasound diagnosis of intrauterine pregnancy

If a specialist conducts an ultrasound examination in the early stages of pregnancy, he will be able to see the fertilized egg in the upper part of the uterus, and it looks like an oval (in some cases, round) dark spot. If the pregnancy is multiple, then the doctor will see two/three and so on such dark spots.

The transabdominal type of the study in question allows us to establish the onset of intrauterine pregnancy at the earliest date - 5 weeks, when the absence of menstruation from the expected start date lasts about 14 days. At this stage, the size of the fertilized egg will be at least 5 mm in diameter.

Transvaginal ultrasound examination of the uterus is more informative - the doctor can confirm the fact of pregnancy even at 4 weeks, that is, after 6 days of missed menstruation. The diameter of the fertilized egg in this case will be 3 mm in diameter, which corresponds to the norm.

As for the visualization of the embryo, with transabdominal ultrasound this can be done at 6 weeks, with transvaginal ultrasound - 5 weeks, and the embryo will look like white spot in the cavity of a dark formation. You can listen to the clear contractions of the heart (beat) of the embryo at 6 weeks.

If a woman has normal menstrual cycle, that is, there are no usual delays or early onsets, then transvaginal ultrasound can be performed at 6 weeks of pregnancy. Such an examination does not belong to the “mandatory program” and is carried out only at the request of the patient. If the menstrual cycle is inconsistent and the period of delay of menstruation cannot be accurately determined, then the estimated duration of pregnancy is determined by an ultrasound specialist.

How to estimate the size and growth of the fertilized egg/embryo

This data is determined by two indicators:

coccygeal-parietal size;
the average internal diameter of the fertilized egg.

For a specific period of pregnancy, there are established indicators (conditional, of course) of the average internal diameter of the ovum, which are included in the program of ultrasound machines. These data automatically establish an almost exact gestational age, but an error of 6 days is allowed in the direction of increase and decrease.

The term “coccygeal-parietal size” means the length of the embryo’s body from the head to the coccyx, and this indicator is measured first. It is by this size that you can more accurately determine the gestational age - the error is only 3 days.

Note:if the average internal diameter of the ovum is 14 mm, but the doctor cannot visualize the embryo, then experts will talk about a pregnancy that has stopped its development.

The principle of assessing the vital activity of the fetus and embryo

Heartbeat and motor activity are the main indicators that allow a specialist to assess the vital activity of the embryo.

If a transvaginal ultrasound examination is performed, then already at 6 weeks the doctor sees the heartbeat of the embryo. If it is within normal limits, then a clear rhythmicity of contractions will be noted, but for each stage of pregnancy they have their own frequency:

6-8 weeks – 130-140 beats per minute;
9-10 weeks – 190 beats per minute;
the entire period before birth - 140-160 beats per minute.

Heart rate must be measured without fail, since it is this indicator that allows specialists to identify problems with bearing a child. For example, if the heart rate is sharply increased or decreased, then doctors will place the woman at risk for miscarriage.

Note:if an ultrasound confirmed that the length of the embryo along the coccygeal-parietal dimension is 8 mm, but heartbeats are not detected, then the specialist may suspect a non-developing pregnancy. In this case, a repeat examination is carried out after 7 days and only after that a final diagnosis is made.

Concerning motor activity embryo - it can be seen already at 7-9 weeks of pregnancy. At first, the embryo simply moves its whole body (chaotically), a little later there are types of flexion and extension of the body. Doctors know very well that the embryo rests very often and therefore the indicator of motor activity cannot be the main criterion in assessing its vital activity.

Assessment of embryo structure

The doctor must pay Special attention the structure (anatomy) of the fetus during an ultrasound examination in the 1st trimester of pregnancy. For example, already at 12 weeks a specialist can diagnose fetal pathologies that will not be compatible with life - for example, a hernia spinal cord, absence of a brain, abnormal skeletal development.

The specialist will definitely evaluate the collar space and determine its thickness - using this indicator it will be possible to identify fetal diseases of a chromosomal nature. An increase in the collar space by 3 mm is allowed, but higher values will indicate the presence of chromosomal pathology in 80% of cases.

Modern medicine has ultrasound equipment latest generation, which makes it possible to diagnose anomalies in the structure of all systems and organs of the unborn child already at 12 weeks of pregnancy. Such an accurate diagnosis allows parents to make a choice - to continue the pregnancy or terminate it for medical reasons.

Study of extraembryonic structures

When conducting an ultrasound examination in the 1st trimester, the specialist will examine the yolk sac, amnion and chorion, and their assessment is mandatory.

Yolk sac- structure that performs important functions– hematopoietic and nutritional, and throughout the entire period of pregnancy. This sac can be identified as early as 5 weeks of pregnancy; by 10 weeks its size reaches 7 mm, but after 12 weeks of pregnancy, even with the help of an ultrasound examination, it is not possible to determine/identify/assess the condition of the yolk sac - this is the norm.

Doctors have long noted a direct connection between the size of the yolk sac and the outcome of pregnancy. The fact is that the incorrect size of the sac, changes in its shape and walls in most cases are accompanied by a delay in the growth of the embryo.

Chorion- This is the membrane of the fertilized egg, which consists of villi. Its size (thickness) is equal to the gestational age in weeks, but this rule “works” only in the first trimester. If there is underdevelopment or changes in the structure of the chorion, then the death of the fetus can be accurately predicted. The fact is that the chorionic villi are very tightly attached to the uterine cavity and if its structure is changed, then it is simply impossible for the villi to “catch on” - a miscarriage begins.

Amnion- this is a water shell, a sac in which the embryo is located surrounded by amniotic fluid. Carrying out this type of study in the early stages of pregnancy allows the specialist to identify the small diameter of the amniotic cavity, and this will indicate its underdevelopment, which always leads to problems with the development of pregnancy. But an increase in size will indicate the presence of intrauterine infection.

Identifying pregnancy complications

In the 1st trimester of pregnancy most often, of all possible pathologies, the threat of interruption is diagnosed. Moreover, it is with the help of the study in question that the doctor can diagnose this pathological condition at the very beginning of its development, the walls of the uterus will thicken. Women very often feel it themselves, as this condition is accompanied by. If the diagnosis has taken place, then doctors carry out therapeutic treatment, which is designed to preserve pregnancy. But if there is a detachment of the fertilized egg, the woman has some from the vagina, then a diagnosis of “incipient spontaneous abortion” will be made.

Important! If a miscarriage has already occurred, the patient must undergo an ultrasound examination to determine whether there are remains of the fertilized egg in the uterine cavity. And if such residues are identified, then the woman is sent for a curettage procedure.

With the help of this study in the early stages of pregnancy, a doctor can diagnose:

Cyst corpus luteum . This is a fairly common formation, which will be characterized by the presence of thick walls, and its structure will be assessed as heterogeneous - in principle, this is considered the norm. The corpus luteum cyst tends to resolve on its own and completely disappears by the end of the first trimester.
Hydatidiform mole. This complication is detected extremely rarely - 1 case in 2,000 - 3,000 pregnant women. Very dangerous condition, which is characterized by pathological damage to the chorion. Hydatidiform mole always leads to the death of the fetus, as the chorion turns into grape-shaped formations that destroy the fertilized egg.