At what gestational age and at what hCG is the embryo visible: the reliability of the study in the first weeks. When can you see a fetal egg on an ultrasound? Whether an ultrasound does not see an embryo

When a desired pregnancy occurs, all expectant mothers want to reliably make sure that fertilized egg attached to the wall of the uterus and the formation of the future baby is normal. The most reliable and convenient way to confirm a positive pregnancy test is considered ultrasonography.

Despite the fact that a high-precision test strip, readily available in the pharmacy network, shows the onset of pregnancy, and a qualified obstetrician-gynecologist is able to recognize the symptoms of a "pregnant uterus", only the final ultrasound data confirms the fact of gestation. That is why, in the case when a woman believes that she managed to get pregnant, and the fetal egg is not visible on the ultrasound, future parents are perplexed.

In connection with this phenomenon, they have a question - can the diagnostician not see the pregnancy on an ultrasound scan? In our article, we want to provide information on how long it is possible to confirm the completion of the conception process, when the ultrasound scanner will allow the doctor to see the embryo, and whether it is possible not to see the pregnancy on ultrasound.

How are expectant mothers examined?

If the pregnancy test turned out to be positive, this can be confirmed by ultrasound - the diagnosis is carried out in a commercial center or in a antenatal clinic. It is important to know that an important role in obtaining reliable examination results is played by equipment that has high level permissions and functionality, as well as the qualifications of the specialist.

Up to 9 obstetric weeks For the examination of pregnant women, two methods are used:

Transabdominal - through the region of the anterior abdominal wall.
Transvaginal - using a transducer that is inserted into the vagina.

Up to 5 weeks, the formed fetal egg is very small - its size is only about two millimeters. It is transvaginal that is considered to be an effective method for diagnosing the embryonic period - its high-frequency sensor makes it possible to get as close as possible to the uterine cavity and transfer the smallest sizes of the organs under study to the monitor screen.

Survey methodology future mother using high-frequency waves, non-invasive and completely harmless - it allows the doctor to safely observe the development of the fetus

For the entire period of gestation, a woman performs at least three ultrasound scans. The examination session is short-term, the doctor tries not to hold the sensor in one place for a long time, especially during the formation of the most important organs and systems of the unborn baby.

What is seen on an ultrasound?

The main purpose of ultrasound in the embryonic period is to confirm the onset of pregnancy, this issue is especially relevant in the case of in vitro fertilization. The doctor-diagnostician has several tasks:

Confirmation of fixation of the fetal egg in the uterus.
Exclusion of the presence of a neoplasm in the uterine cavity, which can "mask" as pregnancy.
Embryo viability assessment.
Exception ectopic pregnancy.
Determination of the presence of a second fetus.
Study of the localization of the placenta and fetus.
Specification of gestational age.

In gynecological practice, there is one important point, which all future mothers should know: the doctor measures the duration of the pregnancy period in obstetric weeks - from the first day of the last menstruation. That is why the difference between the real and obstetric term for conceiving a child is two weeks. In a woman of reproductive age with a normal menstrual cycle, recognition of pregnancy during transvaginal examination occurs no later than five weeks. If the cycle is irregular, it is difficult to determine the exact period for menstruation.

At what time is the embryo not visible on ultrasound?

Signs of a viable pregnancy are the following factors that the ultrasound scanner captures:

the presence of a distinguishable outline of the embryo in the egg;
listening to the fetal heartbeat;
fixation of the slightest movements of the embryo.

For each woman, the period of bearing a child proceeds individually and it is very difficult to say exactly how long it takes for the doctor to be able to examine the fetus in the form of a dot and hear the rhythm of his heart.

In obstetric practice, there are certain normative terms for conducting ultrasound diagnostics for pregnant women. This takes into account that transvaginal scanning allows you to study the ongoing changes before transabdominal. In order for our readers to evaluate the quality of these methods, we provide a comparative table.

The beginning of contractions of the heart muscle of the future baby falls on the period from 3 to 4 weeks and it is possible to catch it only with the help of a transducer (a special narrow vaginal sensor). It happens that the uzist doctor cannot see anything in the fetal egg and recommends coming for an examination in 7-14 days.

It is the frequency of contractions of the heart muscle of the embryo that will allow the doctor to clarify the gestational age:

at 5 obstetric weeks, the heart rate is up to 85 beats / min;
in 6 - from 102 to 126;
in 7 - from 127 to 149;
in 8 - from 150 to 172;
at 9 - 175.

If at 7 obstetric weeks no embryo parameters are observed in the fetal egg and the heart rhythm is not heard, a preliminary diagnosis of anembryony is made - the absence of an embryo in the fetal egg. However, in this case, the woman is also recommended to come for an additional ultrasound after another 7 days.

Embryo parameters

Normally, the fetal egg has an oval shape and a dark gray tint. To fully monitor the formation of the fetus on ultrasound, the following indicators are measured.

Many factors influence the clear visibility of the fetus on the monitor of the ultrasound machine, and if the embryo is not visible, do not panic - you should wait two weeks and repeat the study.

At the beginning of pregnancy, the embryo resembles the letter "C", as it grows appearance changes - at 8 weeks you can already see both the head and the highlighted limbs

Why is the fetus not visible on ultrasound with a growing level of hCG?

The fetal membranes of the developing baby produce a special substance - human chorionic gonadotropin, indicating that the conception has taken place. In the first trimester, the amount of this protein-hormone in the circulating blood of a woman grows very quickly - in the first weeks, its concentration doubles every second day.

Monitoring the growth dynamics of hCG levels allows obstetrician-gynecologists to draw an accurate conclusion about the development of pregnancy.

If, when assessing the amount of this biologically active substance, an increase in its amount is observed, the doctor confirms with certainty the onset and successful development of pregnancy. Every woman wants to know about the onset of pregnancy early, but the accuracy of the ultrasound results in the second week of the delay in menstruation is very low - it is better to wait until the fifth week.

If, with positive hCG tests (in the case when the quantitative final data of the analyzes correspond to the estimated gestational age), pregnancy is not determined by ultrasound, then you need to come for an additional examination. An hCG level of more than 1800 mU / ml corresponds to the third week of pregnancy and, if an ultrasound scanner does not observe a fetal egg in the uterine cavity, the doctor assumes the development of an ectopic pregnancy.

The lack of growth in hCG levels (negative test) may indicate the fact that the development of the embryo does not occur - either it died, or the egg was not fertilized in this cycle.
Not all women know such a phenomenon as biochemical pregnancy or preclinical spontaneous miscarriage. In this case, conception occurs, the fetal egg is attached to the uterine wall, however, when the next period comes, the pregnancy is terminated.

Emphasis should also be placed on those situations where pregnancy is not visible on ultrasound, and the test is positive - monitoring the level of hCG is of particular importance, it is necessary to take a blood test several times, with an interval of several days. The final data of laboratory studies allow us to determine the compliance of the hormone concentration with the norm and its increase.

Practitioners advise future parents to try not to force events, an exception is possible only when it is necessary to confirm or deny the pregnancy as soon as possible

What to do if pregnancy is not detected during ultrasound scanning?

In the event of a situation where the uzist doctor cannot see the outlines of the embryo, and sometimes the fetal egg itself, you must try to remain calm and not succumb to false beliefs! This is possible in the absence of gestation or its period is very short to notice on the monitor. Without the presence of absolute evidence of an interrupted pregnancy, it is impossible to carry out curettage of the uterine cavity!

You should go to another clinic and re-examine - it is better to do this on expert-class equipment with high resolution. It is also necessary that an ultrasound be accompanied. You may need to go through the examination several times. Future parents should make every effort so that diagnostic errors do not cost the child's life!

Women who dream of pregnancy often resort to early ultrasound. The delay in menstruation gives them hope, and to reinforce it, they ask the doctor to conduct additional diagnostics. A referral for an ultrasound examination is issued from the 7th week of pregnancy. What can be seen on ultrasound, what factors can affect the accuracy of the result?

How does pregnancy develop in the first weeks after conception?

After the fusion of the sperm with the female germ cell, the resulting zygote moves to the uterus. After 24 hours, the crushing process begins, leading to the formation of a blastocyst on the 5th day, consisting of approximately 100 cells. On the 8th day, the blastocyst is introduced into the uterine endometrium.

At what time and at what level of hCG is a fetal egg visible during ultrasound?

During the ultrasound, the fetal egg is found in the form of a small black dot. It clearly shows a blurry white spot - the embryo. The study is carried out transvaginally. The fetal egg is an anechoic (not reflecting ultrasonic waves) formation of a round or oval shape. The microscopic dimensions of the embryo at the very beginning of its development do not make it possible to see it with the help of ultrasound. On early dates the sonologist detects pregnancy and determines its duration by detecting the fetal egg and measuring it.

When is an egg well visualized? In the first weeks, the fetal egg grows by about 1 mm per day: at 4 weeks, its diameter is 3 mm, at 5 weeks - 6 mm. Up to 8–10 weeks of pregnancy, its term is determined by the diameter of the fetal egg, then by the coccygeal-parietal size (KTR) of the fetus.

The doctor will be able to see the fetal egg and embryo not earlier than the 5th obstetric week. A convincing sign of the onset of pregnancy is the level of hCG detected by a blood test from 1500 to 5000 IU / l. As a rule, if the result of the analysis is normal, you can go for an ultrasound scan - the doctor will see the fetal egg.

When does an ultrasound determine the presence of an embryo in a fetal egg and what does it look like?

If conception occurred in a woman with a regular menstrual cycle, the diagnostician will detect an embryo at 6-7 weeks. By this time, the size of the fetal egg increases to 7 mm. In addition, during the ultrasound, the heartbeat of the fetus is heard. On the monitor, the embryo looks like the letter "C". Toward the end of the 8th week of pregnancy, clearly visible outlines of the head, legs and arms appear. From next week, the embryo is already considered a fetus.

If during the examination the doctor does not find a fetal egg in the uterus, and all tests indicate pregnancy, you can undergo a second examination 6-7 days after the first. In a situation where the fetal egg is visible, but the embryo is not detected, the procedure can be repeated after 2 weeks. When listening to a heartbeat outside the walls of the uterus, an ectopic pregnancy is suggested.

Why is the embryo not visualized at 6–7 weeks?

The woman saw two stripes on the test, was delighted, came for an ultrasound, but the doctor did not find the embryo. Why at positive test on pregnancy during ultrasound, the embryo is not visualized? Possible reasons:

Incorrectly calculated gestational age. The embryo becomes clearly visible at 6-7 weeks.
The examination was carried out on outdated equipment, or the doctor does not have sufficient qualifications.
The study was conducted transabdominally, in which the error of the result increases.
There was a spontaneous miscarriage, which the woman mistook for normal menstruation. The concentration of hCG did not have time to decrease by the time of the examination, and ultrasound gives a negative result.

If the doctor at the ultrasound examination said that the embryo is missing, the woman should not be very worried. An erroneous detection of anembryony (absence of an embryo) may be due to various factors. An argument in favor of a successful conception is an increase in the level of hCG in dynamics and the absence of bleeding and other signs of an early miscarriage. To obtain the final result, you need to undergo an ultrasound scan again after 7-14 days.

The difference between obstetric and real pregnancy

The gestational age can be obstetric and embryonic. Obstetric is counted from the 1st day of the last menstruation, in the second case, the countdown is from the day of conception, which is taken as the day of ovulation. As a rule, the obstetric period is 14 days longer than the embryonic one.

When conducting an ultrasound, the obstetric period is taken into account. During the procedure, the doctor correlates the identified indicators of embryo development with the obstetric period. The accuracy of the final result depends on the gestational age:

when examining a pregnant woman before the 12th week, the permissible deviation is 1-2 days;
within 12-28 weeks - 1 week;
after the 28th week, the margin of error increases.

All subsequent examinations and analyzes are carried out taking into account the obstetric period. Its duration is 280 days, or 40 weeks. In practice, the difference from the fetal gestational age of 2 weeks may vary for individual reasons. According to statistics, in 20% of pregnant women it is less than two weeks, in 45% it can reach 3 weeks, and in 15% it can exceed 3.

External factors: the quality of the equipment and the qualifications of the doctor

Misdiagnosis during ultrasound is rare. If the doctor does not find the embryo, it is necessary to do a second examination after a week or undergo a procedure on other equipment. It is possible that the specialist conducting the ultrasound examination does not have sufficient qualifications. It is advisable to clarify information about the equipment and the specialist before the ultrasound.

Absence of an embryo

The absence of an embryo in a fetal egg can be caused by various reasons:

acute viral or bacterial infection in a woman in the first weeks of pregnancy;
chromosomal and anatomical defects of the embryo;
bleeding disorder in pregnancy.

There are no pronounced physiological signs of the absence of an embryo in the fetal egg. Even a gynecologist examining a woman cannot detect anembryony. Only a specialist in ultrasound diagnostics can reliably determine the pathology, and then for a period of at least 5-6 obstetric weeks (1-2 weeks after the delay in menstruation).

On the monitor screen, an empty fetal egg is visualized as black spot irregular shape, as a rule, is smaller in size than it should be according to the gestational age. Sometimes a specialist sees a normal rounded ovum, but there is no yolk sac in it. In the first weeks of pregnancy, an ultrasound examination has low information content, therefore it is recommended to undergo the first ultrasound at 10-12 weeks - at this time the fetus is already clearly visible.

What if the ultrasound did not find an embryo?

If the absence of an embryo was detected at 5–7 obstetric weeks, a woman should donate blood for analysis within 1–2 weeks to monitor the level of hCG. Its steady growth in accordance with the norm will be evidence of a developing pregnancy. Stopping growth and lowering the level of chorionic gonadotropin is a signal that the embryo has died. After 1-2 weeks, you need to undergo a second ultrasound.

When the absence of an embryo is confirmed by laboratory tests and the results of a second ultrasound, a decision is made to terminate the pregnancy. A medical abortion is performed, the method depends on the gestational age. If it is 5–12 weeks, vacuum aspiration is performed.

Anembryony is not evidence of a woman's inability to bear a pregnancy. Women who are diagnosed with such a diagnosis are interested in how long it takes to plan a pregnancy again. It depends on the reason for the anembryony. If this happened due to an infectious disease, it is necessary to undergo a course of treatment, and then a complete examination in order to exclude a recurrence of the situation.

In any case, it is necessary to give the body time to fully recover. It is worth planning conception no earlier than six months after the previous attempt.

The last ultrasound at how many weeks - your attending physician will answer this question for you

When pregnancy is desired, expectant mothers rush to make sure that the fetal egg is formed, fixed in the uterus, and the baby develops as it should. Ultrasound examination allows you to confirm the onset of pregnancy from 1-3 days of delayed menstruation. But at the same time, the doctor will not see the embryo, it is diagnosed from 5-6 weeks.

How to see the embryo?

If the test showed the presence of pregnancy, then an examination on an ultrasound scanner will help to verify this. Ultrasound diagnostics are carried out in a antenatal clinic or in a private medical center.

For examination in the 1st trimester, it is important that the ultrasound machine has a high resolution and wide functionality, besides, an important role is played by the qualification of the doctor. At 4–5 weeks, the formed fetal sac is very small and poorly visible, its size is only 1–2 mm.

To understand the medical language, it is important to know that gynecologists measure the duration of childbearing in obstetric weeks, from the first day of the last menstruation. Therefore, the difference between obstetric and real terms of conception of a baby is 2 weeks.

How is the embryo examined?

Research in the early period, up to 9 weeks of pregnancy, is recommended to be done by two methods:

Through the anterior abdominal wall, transabdominal probe;
Through the vagina, transvaginal narrow transducer.

It is transvaginal examination that is considered to be an effective method of diagnosis in the embryonic period, its sensor, having a higher frequency of waves, comes closer to the uterine cavity and transmits the smallest sizes of organs to the screen.

Is ultrasound at the stage of embryo formation safe?

The method of examination with high frequency waves is non-invasive, it allows you to relatively safely observe the development of the child. However, despite the confirmed harmlessness for the embryo, it is recommended to conduct an ultrasound session for a short time, no more than 15 minutes. During the formation of organs and systems, experienced doctors try not to delay the time of diagnosis, do not hold the sensor in one place for a long time.

During the period of pregnancy, a woman does at least 3 ultrasound examinations. Each screening includes an ultrasound scan and a blood test. Later, observing how the pregnancy proceeds, the doctor decides how much additional ultrasound sessions are required.

At what time does an ultrasound see an embryo?

When the outlines of the embryo in the egg are distinguished, the baby's heartbeat is heard on the ultrasound machine, the slightest movements are recorded, then gynecologists confirm a viable pregnancy.

How many weeks exactly must pass from conception in order to see the embryo in the form of a dot, to hear the baby's heart rate, it is difficult to say, since each pregnancy develops individually.

In obstetrics, average terms are taken as the norm, while the method of scanning through the vagina allows you to see changes earlier than superficial.

Normative terms of diagnostics

In the event that a woman has a regular menstrual cycle, then with transvaginal ultrasound, recognition of the embryo occurs no later than 6 weeks. If the cycle is not constant, then it is impossible to determine the exact period by menstruation.

The heart muscle of the embryo begins to contract from 3 weeks and 4 days. It is better to catch the beat of the heart with the help of a vaginal sensor. Sometimes it happens that at this time nothing is seen in the egg, then it is recommended to come another ultrasound in about a week, or even two. The heart rate (HR) will allow you to clarify the gestational age.

If in a week, at 6-7 obstetric weeks, nothing is still visible and audible in the egg, then the doctors will make a preliminary diagnosis - anembryony. However, in this case, gynecologists advise not to rush and undergo an additional examination a little later, in another week, especially with an irregular cycle.

What is seen on an ultrasound?

Ultrasound before 9-10 weeks is not mandatory, it is performed at the request of the woman. The main task of ultrasound in the embryonic period is to confirm the onset of pregnancy and the attachment of the fetus in the uterus. This is especially true in the case of replanting embryos by in vitro fertilization (IVF). There are several goals of ultrasound in the embryonic period:

Confirm that the fetal egg is fixed in the uterus;
Analyze the viability of the embryo;
Exclude ectopic pregnancy;
Determine the number of embryos;
Find out the localization of the fetus and placenta in the uterus;
Clarify compliance with the standards of the shapes and sizes of the fetal egg;
Exclude neoplasms in the uterine cavity, masquerading as pregnancy;
Specify the gestational age.

Embryo parameters

In the first days after conception, the embryo does not look like a person, rather, like a rounded shell with a tail. But as it grows, its appearance changes, and if at 5–7 weeks the embryo resembled the letter “C”, then after a week on ultrasound, the doctor will see the head, arms of the embryo, as a selected part of the body.

When a long-awaited pregnancy occurs, a fertilized egg descends into the uterine cavity and attaches to its wall. Thus, the development of an embryo surrounded by a fetal egg occurs. The first month, from the date of fertilization, the embryo is so small that it is very difficult to visualize it. That is why the first ultrasound is done at 6-7 weeks so that you can examine the embryo and confirm the onset of pregnancy.

Why is the embryo not visible on ultrasound?

It happens that a woman who saw the long-awaited two stripes on the test comes to the doctor and hears: "The fetal egg is empty, the embryo is not visible on the ultrasound." This phenomenon is called an embryonic pregnancy.

If a pregnant woman is given anembryony, this means that with an increase in the level of hCG in the blood, there is no embryo in the fetal egg. It is difficult to say exactly which week specialists will be able to see the embryo on an ultrasound scan. This period ranges from 5 to 9 weeks, depending on certain factors:

Features of the body of each particular woman.
The correctness of the calculation of the period from the date of conception.
What kind of pregnancy is on the account. With each subsequent pregnancy, the probability of detecting an embryo earlier increases significantly.

On average, it is determined that visualization of the embryo is feasible at 7 weeks from the date of conception, with an active ongoing increase in the level of hCG in the blood. However, even if at this time the experts did not see the embryo in the fetal egg, you need to panic only if the growth of the hCG level has stopped or it has begun to decline. This picture indicates that the pregnancy is frozen. However, it won’t hurt to make sure of this once again, so it’s worth double-checking everything with another doctor or doing an ultrasound transvaginally.

A woman needs to see a doctor if, a few weeks after the growth of the hCG level has stopped, the embryo is not visible in the fetal egg, even when examined transvaginally, while the gestational age is approaching nine weeks. Stopping the growth of the embryo and the beginning of its decomposition may be accompanied by such concomitant symptoms:

An unreasonable jump in body temperature.
Appearance of nausea and vomiting.
Constant weakness, muscle pain.
Lower abdominal pain.
The appearance of discharge with blood impurities or open bleeding.

Do not delay a visit to the doctor and postpone the curettage procedure. The decomposition of the embryo can threaten a woman with serious health problems.

At what time should the embryo be visible on ultrasound?

While waiting for the birth of a baby, a woman wonders at what time the embryo can be examined on an ultrasound scan? During the diagnosis for a period of 5-6 weeks, the fetal egg is about seven millimeters in diameter. At this time, in most cases, the doctor already visualizes the embryo. Around this time, you also manage to hear how his heart beats.

If you have a regular menstrual cycle, an embryo should be visible at the end of the sixth week. If the ultrasound does not show the embryo, it is recommended to undergo a second examination in a week to exclude all possible deviations.

There are also cases when the fertilized egg is outside the uterus. During ultrasound, the egg is not visible well enough, or it is not visible at all. In this case, the heartbeat is heard outside the walls of the uterus.

What to do if the fetus is not visible on the ultrasound and what can this mean?

There are situations that during the ultrasound scan, the embryo is not visualized inside the fetal egg, and sometimes the fetal egg itself. First of all, try not to panic. Maybe there is no pregnancy at all, or there was an error with the calculation of its term, so it is still difficult to diagnose. If the frozen pregnancy is not exactly confirmed, there is no need to rush to clean. First, it is better to undergo an ultrasound scan again, in another clinic. It may be necessary to conduct one or more studies. The best option- when, in parallel with the diagnosis, the level of hCG in the blood is monitored. If the pregnancy develops without deviations, then its level increases. This helps specialists to exclude a possible frozen pregnancy.

If an ultrasound does not show an embryo in a fetal egg, what does this mean?

Very often, a fetal egg without an embryo is diagnosed in the uterine cavity in young and healthy girls. Why is the fetus not visible on ultrasound, and is it possible to avoid a missed pregnancy?

There are many reasons for this phenomenon. This can be caused by infections of various etiologies, exposure to toxic substances, etc. on the body. You can minimize the possibility that an embryo will not be visible on an ultrasound by planning your pregnancy in advance in order to accurately calculate the gestational age. Also, you need to undergo examinations and, before planning the conception of a baby, cure all existing infections. This is especially important for women who are planning a pregnancy over the age of 35. This category has a significantly higher risk of chromosomal abnormalities in the fetus.

The absence of an embryo in a fetal egg often does not give a woman any signs during pregnancy. Can appear bleeding in the event that a miscarriage has begun. Even a gynecologist during the examination will not be able to say for sure whether there is an embryo in the fetal egg, or whether it is empty. The diagnosis of anembryony can only be made by a doctor who performed an ultrasound examination for a period not earlier than 5-6 weeks. If the gestational age is considered from the first day of the beginning of the last menstruation, then the doctor can visualize the embryo on ultrasound at 1-2 weeks of delay.

It is extremely rare for a patient to be misdiagnosed after an ultrasound, therefore, if there is no embryo in the fetal egg, it is necessary to check the result in a week on other equipment if there are doubts about the professionalism of the doctor or the quality of the ultrasound machine. An error is also possible for other reasons: a short gestational age or late ovulation, excess weight women and.

Why can't you see an embryo on an ultrasound?

If the pregnancy test shows two stripes, and the embryo is not visualized on the ultrasound, the reason for this may be:

Incorrect calculation of the gestational age from the moment of conception. The embryo may not be visible because the woman is doing the test too early.
Ultrasound diagnostics was carried out on an old apparatus or the specialist did not have the proper level of qualification.
The study was done through the abdomen, not transvaginally.
The pregnant woman had a miscarriage, but she did not pay attention to it (confusing it with the onset of menstruation), while the level of hCG in the blood had not yet decreased to its previous value.

If the ultrasound does not show the embryo in the fetal egg, do not immediately panic. For a number of reasons, the diagnosis of anembryonia can be erroneously made, so it is necessary to control the level of hCG in the blood and undergo the diagnosis again.

Ultrasound is an important diagnostic procedure for gynecological examination. It is especially important for monitoring the development of the fetus. Thanks to ultrasound diagnostics, it became possible to visually assess the embryonic development of the child, determine the compliance of the development of the baby with the estimated gestational age. The doctor can determine not only the level of development of the fetus, its size, but also find out what condition it is in, i.e. identify his possible suffering (for example, hypoxia). This helps obstetricians-gynecologists to form the right strategy for managing pregnancy. Ultrasound, as a diagnostic method, allows you to confirm the very fact of pregnancy.

Ultrasound diagnostics can confirm or deny the fact of pregnancy with almost one hundred percent probability.

When can pregnancy be confirmed by ultrasound?

It makes no sense to run for an ultrasound the next day after unprotected sex. The size of the egg, even a fertilized one, does not allow it to be seen with ultrasound imaging. How long does it take to see the fetal egg and determine its size? You can see the embryo when the fetal egg is at least 1 cm. If there was a delay in menstrual bleeding for a week, by this time the gestation process has approximately reached 6 weeks. By this period, when diagnosing with a high-precision apparatus, the fetal egg is already visible. It is not yet possible to determine the presence of an embryonic heartbeat and consider its structure.

Due to the peculiarity of ultrasound diagnostics in the early period of gestation, namely the need to insert a transducer into the vagina, such an examination is carried out strictly according to indications. The grounds are the suspicion of ectopic fixation of the fetal egg, cystic drift.

There may be other considerations, based on which the gynecologist offers the woman this procedure.

When is a qualified, highly experienced specialist on a good device that provides high-quality visualization able to recognize the signs of pregnancy? After 3 weeks. The ectopic location and fixation of the fetal egg is diagnosed by ultrasound after 2 weeks (transvaginally) and on the 20th day after conception (through the peritoneum). To help the data of ultrasound diagnostics, a blood test is usually prescribed. HCG indicators make it possible to judge the implantation of the embryo. At 7-8 weeks (from about 10 days of delay), a good ultrasound diagnostician determines pregnancy with almost 100% certainty.

Why doesn't ultrasound "show" pregnancy?

If all signs of gestation are present, the level of gonadotropin indicates successful implantation embryo, and ultrasound data do not show a fetal egg and do not confirm the fact of pregnancy in a particular patient, this does not mean that the pregnancy did not take place. The reasons why an embryo is not visible on an ultrasound may be as follows:

used transabdominal sensor;
low accuracy of the equipment;
incorrect calculation of gestational age, ultrasound diagnosis is carried out early, the fetal egg is not visualized;
gynecological pathology (yellow cyst, for example).

For the expectant mother in this situation, the main thing is not to panic. It is necessary to repeat the hCG test (its indicators should double in 2 days - this is an indicator of a normally developing pregnancy) and re-visit the ultrasound room in a week.

The use of a transvaginal probe is much more informative for detecting a normally located embryo than a transabdominal examination.

What justifies the need for early ultrasound diagnostics

With a hCG result of 1000-2000 mU per liter, ultrasound can be effective. This study will help the obstetrician-gynecologist recognize possible early pregnancy problems and its rate. It could be:

ectopic pregnancy;
confirmation of the fact of embryo implantation;
finding out the reasons for the delay in menstruation in the absence of pregnancy;
establishing the gestational age (the smaller it is, the more accurate the data);
determination of pregnancy fertility (not always possible);
establishment of the threat of disruption.

Ultrasound diagnostics in the early period is carried out only in exceptional cases, but still it is better to wait 5-8 weeks. At this time, the embryo is visible and it is already possible to determine the rate of its development.

If the ultrasound was performed early, the suspicion of pregnancy is the size of the corpus luteum. With a delay in menstruation and a corpus luteum size of at least 16 mm, we can talk about pregnancy, although the fetal egg is not yet visible.

How long does ultrasound show and its accuracy?

The age of the fetus is determined by the obstetric method and embryonic. The first is counted from the 1st day of the last menstrual bleeding, the second counts the time of gestation from the day of conception (this date is considered the day of ovulation). The embryonic period is 2 weeks shorter than the obstetric one. In the ultrasound procedure, the obstetric reference method is considered the basis. The procedure itself is not a computational mechanism for calculating the gestational period. It consists in determining the degree of fetal development and correlating the data with the obstetric period. The accuracy of ultrasound (by determining the number of weeks of pregnancy) directly depends on the gestational age itself:

up to 12 weeks - accuracy is 1-2 days;
from 12 to 28 weeks - the error is a week in both directions;
after 28 weeks, the error increases.

After 12 weeks, the accuracy of determining the gestational age is significantly reduced.

The term of ultrasound does not coincide with obstetric: reasons

A deviation of 14 days in both directions is not considered a pathology, obstetric practice allows this. For example, if the terms according to ultrasound exceed the obstetric calculations in the initial period of gestation, the reason may be an error in determining the obstetric term, due to the fact that almost immediately after fertilization there were small bloody issues, which the woman took for menstruation. The second reason may be large sizes fetus.

When researching, it is necessary to take into account the heredity of the baby. Large parents may have large children, short miniature couples and children may be small. Also, the fetus on ultrasound may be smaller in size than it should be according to the estimated period, if the doctor recorded the embryonic period. This is where natural causes end.

The fetus may develop inappropriately with hypoxia or other pathologies. To clarify the condition of the child in the womb, the doctor prescribes dopplerometry. For a woman, this procedure is no different from the studies she has already undergone, but it allows you to clarify the diagnosis.

What to do if the size of the fetus does not correspond to the obstetric term?

Consult with your doctor. He will conduct an examination, determine the height of the uterus and measure the circumference of the abdomen, evaluate the indications of the mother's condition and suggest either hospitalization or re-examination in a week. There is no need to refuse hospitalization and re-examination, because not only the condition of the expectant mother, but also the life of her child depends on this. In the hospital, additional examinations can be carried out, which will either show that everything is fine, or help prescribe adequate treatment.

Ultrasound diagnostics is an art. Much depends on the qualifications of the doctor. A good specialist on precise equipment is able to determine pregnancy with a vaginal sensor for a period of 3 weeks or more (according to the obstetric method). But in fact, how many weeks the doctor can confirm the pregnancy depends on the individual case.