Rus Articles Journal

It is already visible? Ultrasonography in the first trimester of pregnancy

Supervision in a maternity welfare unit over the pregnant woman is carried out according to a certain scheme. What enters it and why all these numerous surveys, analyses and inspections are necessary?

the Ultrasound is used by

in obstetrics not so long ago - from the middle of 1960 - x years. And, despite it, today it is already impossible to imagine inspection of the pregnant woman without ultrasonography. During this time doctors saved up extensive practical experience in application of this method of research, were repeatedly improved OUSE - scanners, appeared three - and four-dimensional ultrasonography, and the most important, grew not one generation of healthy children.


As the ultrasound works?

Ultrasound are called by the sound waves extending in space with high frequency (it is higher than 20 kHz). Sensors of BONDS - scanners are at the same time both a source and the receiver of ultrasonic waves. Ultrasonic wave, passing through various fabrics in an organism, changes the speed and it is reflected, all these changes are fixed and will be transformed to the image on the monitor of BONDS - the scanner. Now at inspection of pregnant women two types of sensors are used: transabdominal - THAT (by means of them research is conducted through a forward belly wall) and transvaginal - TV (research is conducted through a vagina). In the first trimester both types of sensors can be used, but more informatively transvaginal ultrasonography because TV - the sensor is brought closer to a uterus and has the big frequency of radiation of BONDS - waves that gives more accurate image on the monitor of BONDS - the scanner. From the second trimester generally transabdominal ultrasonography is used.


of ultrasonography of pregnant women it is carried out three times - in 10 - 14 weeks, 20 - 24 and 30 - 34 weeks. If necessary the doctor the obstetrician - the gynecologist can appoint additional ultrasonography, and even not one.

Ultrasonic research of a fruit (ultrasonography, an ekhografiya) is the only rather informative and safe method of research allowing to estimate development of pregnancy from the very beginning of and before childbirth. The first visit to an office of ultrasonography is necessary to future mother already at the beginning of pregnancy.

needs to be prepared by

For transabdominal ultrasonography - to fill a bladder. For this purpose it is necessary to drink about 300 - 500 ml of liquid without gas in 30 minutes prior to research. With itself on research it is necessary to take a pure diaper or a towel. During research special transparent gel without color and a smell is applied on a stomach and on the sensor. To transvaginal ultrasonography of special preparation it is not required. It is only necessary to empty a bladder before research. During research the special protective cover or a condom is put on the sensor and gel is applied.

Research lasts on average 10 - 30 minutes. After that the doctor fills in the special protocol in which in detail writes down all results of ultrasonography.


In the first trimester of pregnancy of ultrasonography it is carried out on purpose:

Research of a structure of an embryo and fruit

the Special attention at ultrasonography is paid by

to anatomy of the developing embryo as already at the end of the first trimester rough malformations, such as an anentsefaliya (lack of a brain), hernia of a spinal cord, anomaly of a skeleton, etc. can be revealed. The head of an embryo is defined in the form of separate roundish education from 8 - 9 weeks of pregnancy. The majority of bodies of a chest and belly wall are defined after 10 - 11 weeks of pregnancy.

Should pay special attention to an ekhografichesky marker of chromosomal violations - vorotnikovy space (Nuchal translucency - NT). The Vorotnikovy space is measured on a back surface of a neck in 10 - 14 weeks of pregnancy at KTR of a fruit of 45 - 84 mm. Normal the size of vorotnikovy space should not exceed 3 mm. Increase in this indicator allows to diagnose up to 80% of chromosomal violations at the end of the first trimester.

in process of improvement of BONDS - devices the diagnosis of malformations given about an opportunity warmly - vascular system, the central nervous system (CNS), zheludochno - an intestinal path (gastrointestinal tract), an urinary system till 12 weeks of pregnancy collect.


Research of ekstraembrionalny structures

Besides an embryo at ultrasonography is estimated a zheltochny bag, horion and amnion.

the zheltochny bag (the extra embryonic structure which is carrying out nutritious and haematogenic functions in the first weeks of pregnancy) is defined by

At physiological pregnancy at SVD of fetal egg more than 10 mm (pregnancy term more than 5 weeks) in the form of a ring of white color with a diameter from 2 mm (5 weeks) to 7 mm (10 weeks). A sign of not developing pregnancy also is lack of a zheltochny bag at fetal egg more than 10 mm. After 12 weeks of pregnancy the zheltochny bag normal is not defined. There is an interrelation between the sizes of a zheltochny bag and the result of pregnancy. Increase in over 7 mm and reduction less than 2 mm, irregular shape and a thickening of walls of a zheltochny bag predictively are significant only at a combination to other violations, such as change of thickness of a horion (a fleecy cover), an embryo growth inhibition. The isolated discrepancy of the sizes of a zheltochny bag to norm authentically does not influence the frequency of complications of pregnancy.

Horion - an external fleecy cover of fetal egg. The fruit part of a placenta is formed of a horion. At ultrasonography horion it is visualized as the white ring with wavy contours located on the outer edge of fetal egg. Thickness of a horion in millimeters is approximately equal to pregnancy term in weeks in the first trimester. The underdevelopment of a horion (hypoplasia) or change of its structure often leads to spontaneous interruption of pregnancy. Vorsina of a horion are interconnected with internal (detsidualny - disappearing) a uterus cover. At violation of this interaction there is an otsloyka of fetal egg. The hematoma (a limited congestion of blood) is as a result formed retrokhorialny (located for horiony). The Retrokhorialny hematoma - the terrible sign testifying to the begun abortion.

Amnion - the water cover representing the closed bag in which there is an embryo / fruit surrounded with amniotic waters. Amnion adjoins to a horion from within. The hypoplasia (underdevelopment) of an amniotic cavity leads to not developing pregnancy. In such cases diameter of an amniotic cavity does not exceed 10 - 12 mm on term more than 6 weeks of pregnancy. The increase in the sizes of an amnion characteristic of early abundance of water, and its non-uniform contents (a suspension in amniotic waters) are often connected with existence of an infection. Early abundance of water is an adverse sign.

Diagnostics of complications of pregnancy

the Most often found pathology in the first trimester is pregnancy interruption threat. The echo - a sign of threat of interruption is the basic a local thickening of muscles of a uterus (a hyper tone a miometriya). Several sites of a hyper tone can be defined. At the same time the form of fetal egg changes: from roundish or oval it becomes wrong, sometimes strongly deformed. The most adverse situation - when the site of the raised tone is located in the place of formation of a placenta: in this case the otsloyka of fetal egg and interruption of pregnancy is possible.

In most cases a hyper tone the miometriya is followed by pains in the bottom of a stomach. At the same time the treatment directed to pregnancy preservation is necessary. In case fetal egg loses touch with a wall of a uterus and exfoliates from the bed, the retrokhorialny hematoma is formed (a limited congestion of blood between fetal egg and a wall of a uterus). It is characteristic of the begun abortion. At a considerable otsloyka there is a deformation and reduction of the sizes of fetal egg, and death of an embryo. Clinically at the same time bloody allocations of various intensity are usually observed. Pregnancy interruption also confirm shortening of a neck of a uterus to 2,5 cm (norm of 3,5 - 4 cm) threat and funneled expansion of an internal pharynx.

If against bloody allocations from a genital tract at ultrasonography expansion of a cavity of a uterus and existence in it of non-uniform contents is found, and fetal egg is not visible, then the incomplete abortion is diagnosed. In this case hospitalization in office of gynecology is necessary for carrying out a scraping of the remains of fetal egg and a stop of bleeding.

For not developing pregnancy the smaller sizes of fetal egg are characteristic

of this term of pregnancy, its deformation, an illegibility of contours, reduction of thickness of a horion, lack of warm reductions of an embryo.

Localization of fetal egg in the tservikalny channel (the channel of a neck of a uterus) is characteristic

of cervical pregnancy. At the same time the best visualization is reached at transvaginal ultrasonography. In this situation urgent hospitalization in a hospital as the probability of plentiful bleeding is very high is necessary.

Rather often during pregnancy in one their ovaries the cyst of a yellow body which is represented education with a diameter from 3 to 8 cm with thick walls and non-uniform internal structure meets. It is norm option. Characteristic of this cyst - gradual reduction of its sizes and disappearance by the end of the first trimester.

Puzyrny drift - the rare complication observed in 1 case on 2000 - 3000 pregnancies, connected with pathology of a horion at which there is a transformation of a horion into the racemose educations destroying everything other structures of fetal egg. At the same time the uterus is filled with a set of vials of liquid. At ultrasonography the uterus with sizes more norm for this term of pregnancy, with the expanded cavity filled with non-uniform contents (a so-called picture of “blizzard“) is visualized.

of the Disease and defects of internal genitals


When carrying out ultrasonography of bodies of a small pelvis estimate the sizes of a uterus and ovaries, and also existence of pathological changes (uterus myoma - a benign tumor of a uterus, cysts and tumoral diseases of ovaries) and congenital malformations (a saddle uterus, a two-horned uterus, doubling of a uterus, a partition at uterus cavities, etc.). The situation is most adverse, at which the placenta is located over miomatozny knot. At the same time there is a high risk of a premature otsloyka of a placenta.

the increasing popularity is got Now by three-dimensional ultrasonic research at which “the volume picture“ turns out. The three-dimensional ultrasound allows to diagnose some malformations on earlier terms (for example, defects of the person: cleft lip, etc.) . But ZD - scanning is longer research, and, unfortunately, it is not always possible to receive the necessary image. And experiment on three-dimensional ultrasonic research is saved up still insufficiently. Therefore, most likely, behind this method the future, and now three-dimensional ultrasonography is only an additional method of research.

So, ultrasonic research of a fruit and bodies of a small pelvis in the first trimester of pregnancy is one of the most important and irreplaceable methods of diagnostics allowing to estimate development of pregnancy from the earliest terms and to choose the correct tactics of its maintaining.