Ultrasound is the only method that allows diagnosing a developing pregnancy in the early stages. The pregnancy test can be positive for both ectopic and frozen pregnancy, and after ultrasound, it is already evident at the beginning of pregnancy what is happening in the uterus.
What is visible on ultrasound in the early stages?
Up to 3 weeks of pregnancy on ultrasound, pregnancy is not yet visible, except that on the vaginal sensor. But if a woman is interested in maintaining pregnancy, then the vaginal sensor is usually not used to not provoke miscarriage. After 3 weeks on a normal ultrasound, a fetal egg is already visible (looks like a black round ball in the uterus).
Early diagnosis of pregnancy on ultrasound
At the beginning of pregnancy on ultrasound in the uterus, a fetal egg is seen:
- in 3 weeks - 0.8 cm;
- in 4 weeks - 1.4 cm;
- in 5 weeks - 2.0 cm;
- at 6 weeks - 2.7 cm;
- at 7 weeks -3.4 cm;
- in 8 weeks - 4.0 cm;
- in 9 weeks - 4.7 cm,
- in 10 weeks - 5.3 cm,
- in 11 weeks - 6.0 cm;
- in 12 weeks - 6.7 cm;
- after 12 weeks of pregnancy, the fetus is not measured.
The fetal egg should be in the uterus. If a positive test for pregnancy in the uterine cavity of the fetus is not found, it should be sought in the fallopian tubes (with ectopic pregnancy).
The embryo on ultrasound in the early stages
In addition to the fetal egg, from the 6th week of pregnancy an embryo is seen, and it is started to measure. In accordance with the size of the fetal egg and embryo, the tables determine the duration of pregnancy by ultrasound. The embryo is measured from the parietal to the coccygeal bone in length, the feet are not measured at this time, this size is called the coccyx-parietal (KTP):
- from 6 to 7 weeks of pregnancy KTR 7-10 mm;
- from 7 to 8 weeks KTR 11-15 mm;
- from 8 to 9 weeks KTR 16-22 mm;
- from 9 to 10 weeks KTR 23-31 mm;
- from 10 to 11 weeks KTR 32-41 mm;
- from 11 to 12 weeks KTR 42-53 mm;
- from 12 to 13 weeks KTR 54-66 mm;
- from 13 to 14 weeks KTR 67-80 mm.
If the CTE is greater than 80, then it is not measured, and the size of the fetus will already be different, outside the table to determine the gestation period. In addition to measuring KTP, which should increase with the period of pregnancy, the developing pregnancy is also determined by the heartbeat of the fetus, which appears from 5-6 weeks, is seen on ultrasound at 7-8 weeks and must appear from 9 weeks of pregnancy in a live embryo. If the heartbeat is not determined before 9 weeks, then you can designate a control ultrasound after 10 days, if it is not re-examined, besides, the KTP and the fetal egg do not grow - the pregnancy is frozen.
At carrying out of US at an early stage of pregnancy with 7 weeks define the first movements of a fruit. At first it is uneven twitching, from 8 weeks it is the movements of the trunk, and from 9-10 weeks - movements and extension of the limbs.
In addition to the above-mentioned sizes, when carrying out ultrasound at an early stage of pregnancy, three sizes of the uterus (length, width and thickness) are measured, examine its shape. In this case, note whether there are segmental contractions of the uterus, detachment of the fetal egg, any formations in the uterus and ovaries, partitions in the uterus. The fetus measures the thickness of the cervical fold (for early diagnosis of Down syndrome), the thickness of the chorion (the future placenta).
Ultrasound in early terms has its own peculiarities: up to 6 weeks, one egg in the uterine cavity or more is determined. When embryos appear, they separately follow the development of each of them. If in the early stages of the fetal egg was one, and from 7 weeks there are 2 embryos, then check how many eggs they have and the chorion. If the fetal egg and the chorion are one, then the fruits are examined for adhesions, in due course - for the absence of malformations.
There is an opinion that ultrasound in early terms is harmful, especially because the fetal tissues can become warm and damaged. Especially this applies to fluid-rich tissues (such as the brain of a future child). But ultrasound can already in the early stages reveal serious malformations, many of which are incompatible with the life of the unborn child.