Diagnosis of early pregnancy

Visualization of the fetal egg is the first sign of an early pregnancy. Most often, the fetal egg is detected after 5 weeks of amenorrhea and is more often asymmetrically located in the uterine cavity.

Any normal pregnancy should be detected in time not later than 6 weeks by the presence of a "double echogenic ring" in the uterine cavity. Internal ring of a homogeneous hyperechoic structure, 2 mm thick and thicker. There is a thin unclosed hyperechoic ring around, which does not completely surround the fetal egg. Between the two rings there is an anechoic residual uterine cavity.

In terms of 5-6 weeks, the largest diameter of the fetal egg is 1-2 cm. In 8 weeks the fetal egg occupies half of the uterus: at 9 weeks it takes 2/3 of the uterus, in 10 weeks - completely the entire uterus.

The pregnancy period with an accuracy of 1 week is determined by the average diameter of the fetal egg. On the longitudinal section, measure the maximum size along the length (length), at an angle of 90 ° - the anteroposterior dimension (AP). Make a transverse section at a right angle to the longitudinal plane and measure the largest size of the width of the fetal egg. The average diameter of a fetal egg is defined as the arithmetic mean of three dimensions.

Average diameter of fetal egg = Length + Anteroposterior size + Width / 3

The gestational age of the fetus can also be determined by standard tables.

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Intrauterine devices (IUDs)

Are there intrauterine contraceptives?

Ultrasound is the ideal method for determining the position of the intrauterine contraceptive in the uterine cavity - whether the spiral is correctly located or it has fallen out of the uterus.

If the patient is confident that she has an IUD, but she is not visualized in the uterine cavity or in the pelvic cavity, the entire abdomen should be examined. IUD can be determined anywhere, right up to the splenic angle. If there is any doubt, it is necessary to conduct a radiographic examination (pregnancy in this case should be excluded) of the entire abdominal region, from the diaphragm to the pelvic floor.

IUD and normal pregnancy

If BMC is located at a significant distance from the place of attachment of the fetal egg, the pregnancy can develop normally.

With partial loss of spiral, pregnancy can also develop without complications.

If the "mustache" of the spiral is defined in the vagina, you can try to carefully remove the spiral.

In all other cases spontaneous miscarriages are possible, and the patient should be warned about this possibility.

Ectopic pregnancy

In the case of an ectopic pregnancy, a fetal egg can be visualized outside the uterine cavity. Sometimes in the uterine cavity a structure resembling a fetal egg is determined, despite the fact that the pregnancy is an ectopic. The true fetal egg can be distinguished from the false for the presence of parts of the embryo, the yolk sac, and also the double ring, while the false egg has one hyperechogenic ring.

[4], [5], [6], [7]

Embryo

Although the fetal egg can be determined echographically from 5 weeks, in some cases and from 6 weeks gestation, in most patients the embryo begins to be visualized only from the 8th week of pregnancy. The embryo is defined as a hyperechoic structure located eccentrically in the cavity of the fetal egg. If the embryo is alive, then in the middle part, in the projection of the thorax, palpitation is determined closer to the front.

After 9 or 10 weeks, the fetal head can be differentiated from the trunk, in addition, the movements of the embryo can be determined. With the 10th week of pregnancy, the fetus becomes more and more like a human. After 12 weeks, the skull begins to be visualized.

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Yolk sac

From the 7th week of pregnancy, one can usually see a rounded cystic formation 4-5 mm in diameter near the fetus. It is the yolk sac, the place where primary blood cells form. The yolk sac disappears approximately in 11 weeks of pregnancy. The yolk sac can not be visualized even with a perfectly normal pregnancy.

It is important to see the cystic cavity in the yolk sac and not confuse it with the second embryo - the twin. (The yolk sac should not be included in the measurement of the coccygeal-parietal size.)

Multiple pregnancy

Multiple pregnancy is diagnosed with 8 weeks of pregnancy; nevertheless, not every determined fetal egg contains an embryo. Never tell the patient about multiple pregnancies until two or more normally developing embryos are clearly visualized. This can be determined in the period around 14 weeks of pregnancy, but better - from 18 to 22 weeks.

Multiple pregnancy is usually recognized at about 8 weeks, but you do not need to tell the patient about this before re-examining after 14 weeks.

If a multiple pregnancy is suspected during early pregnancy, use longitudinal scanning. The abdominal muscles can create artifacts that simulate multiple fetuses (lens effect).