Ultrasound in 2-3 trimester of pregnancy: norms, decoding
For the entire period of bearing the child, ultrasound examination of the fetus is carried out three times in accordance with the trimesters.It is this type of examination of pregnant women that doctors consider the best choice.First, there is no need for specific training.Secondly, the procedure passes quickly and in a calm environment, there are no negative emotions and / or painful sensations.Thirdly, the results of the study are immediately reported to the patient.Table of contents: What does ultrasound show in the 2nd and 3rd trimester of pregnancy? Norms and transcript of ultrasound in 2-3 trimester of pregnancy Possibilities of ultrasound in 2-3 trimester of pregnancy
What does ultrasound show in the 2nd and 3rd trimester of pregnancy?
The very first ultrasoundThe pregnant woman should pass on a period of 10 weeks, that is in the first trimester .Of course, this procedure is allowed to be carried out at an earlier time - for example, it is already possible in 4-6 weeks of pregnancy and to confirm the fact of conception, and establish a term, and even determine the nature of the pregnancy( developing or frozen).Ultrasound, conducted in the first trimester of pregnancy, allows you to identify the pathology of the fetus, which allows parents to decide on the appropriateness of further bearing of the fetus.
The second time for ultrasound, a woman will be sent for a period of 20-24 weeks, which corresponds to the 2 trimester of pregnancy.With this procedure, the specialist will be able to: locate the placenta;
- assess the condition of the cervix;
- reveal abnormalities in fetal development, including anatomical abnormalities;
- determine the condition of the cervical canal.In addition, in the second trimester, ultrasound can already measure the mass of the unborn child and even( it is most likely the parents most concerned about it!) To determine the sex, but only if the embryo has adopted a position that the doctor sees wellHis genitals.
In the third trimester of pregnancy, ultrasound is performed so that doctors can prepare themselves and prepare a woman for the forthcoming delivery of .The specialist will evaluate the condition of amniotic fluid based on the results of the study in question, can identify the presence of intrauterine infection and fetal pathology of a hereditary nature.The most important thing is that ultrasound can determine the speed of blood flow in the umbilical cord in the third trimester of pregnancy.If there are any violations of this indicator, the doctor will diagnose "fetal hypoxia", which means insufficient supply of oxygen to the unborn child.Such a situation carries a certain danger and in especially severe cases, specialists consider it expedient to carry out an early delivery.
Norms and transcript of ultrasound 2-3 trimester of pregnancy
Obstetric ultrasound, that is, carried out in the second and third trimester of pregnancy, allows not only to establish the term of the expected delivery and estimate the size of the fetus.Specialists with this examination of women can diagnose the delay in intrauterine development and assess the extent of the problem, because in some cases, parents decide not to continue to carry the child( for example, delay in development leads to irreversible processes and the newborn will not be viable). To ensure that such a diagnosis of intrauterine growth retardation has been carried out, a specialist must make certain measurements:
- At a period of 7-13 weeks, he will determine the coccygeal-parietal size, which will establish the exact duration of pregnancy.Such measurements of the embryo will help to further control its development - for example, if during the next ultrasound examination( it will be prescribed in 6-8 weeks after the first field) the doctor will put a shorter period of pregnancy, this will clearly indicate that the fetus does not develop.
- At 13 weeks of gestation, the doctor can calculate the biparietal size - in this period it will be equal to 2, 4 cm, but by the end of the pregnancy should already be 9.5 cm. Bi-parietal size is the distance between the left and right side of the head.This indicator can determine the reliable age of the fetus, but only in the early stages, because in the third trimester this indicator acquires a variable / individual character.
- The measurement of femur length( the longest bone in the human body) is carried out at the gestational age of 14 weeks.At this time the length will be about one and a half centimeters, but by the end of pregnancy this figure will increase to 7.8 centimeters.
Note: is a very important measurement in the late pregnancy is the circumference of the woman's belly, which will give an idea of both the size of the fetus and its weight.This indicator can not inform specialists about the duration of pregnancy, but still plays an important role in the study of the patient.
Possibilities of ultrasound in 2-3 trimester of pregnancy
This type of study allows the doctor to get maximum information about the course of pregnancy, the state of the fetus. What can the doctor determine by ultrasound in the second / third trimester of pregnancy:
- Fetal pathologies.Already on the 20th week of pregnancy a specialist can diagnose congenital pathologies in the fetus - for example, achondroplasia, hydrocephalus, heart defects, omphalocele, "hare lip" and others.It is easy enough to diagnose Down's syndrome - it will be indicated by excessive thickening of the collar space and the absence of the nasal bone.
Please note: specialists do not confine themselves to the results of ultrasound examination only when detecting congenital pathologies in the fetus.Often, in order to confirm the diagnosis, a pregnant woman is sampled for amniotic fluid and chorion particles for laboratory tests.
- Location and condition of the placenta.The doctor by performing an ultrasound examination can put or exclude the diagnosis of "placenta previa", as there will be results on the exact location of the placenta.Assessing the placenta, a specialist is able to diagnose fetal dropsy and other pathologies of the fetal development of the unborn child, which can be triggered by diabetes maternal diabetes and Rh-conflict.
- Features of the development of multiple pregnancies.Ultrasound in the second / third trimester allows the doctor not only to determine the number of fetuses in the uterus, but also to assess their intrauterine development, the location of each placenta.
- Amount of amniotic fluid.Of course, it should be within the established norms, but if the doctor determines too much or too little of them, the question will be raised about the delay in the development of the fetus, or about the presence of any pathologies.This will allow the timely conduct of a number of diagnostic activities.
The norms for the number of amniotic fluid are given in the table:
In addition, this type of study, conducted in the second and third trimester of pregnancy, is used to determine other parameters:
- abnormalities of the uterus;
- fetal presentation - can be pelvic or head;
- assessment of locomotor activity.
If doctors suspect a frozen pregnancy, then ultrasound can confirm or disprove fetal death.
Only doctors can evaluate the importance of ultrasound in the second / third trimester of pregnancy, because they must identify pathologies in a timely manner and provide comprehensive medical care to the patient.
Tsygankova Yana Aleksandrovna, medical reviewer, therapeutist of the highest qualification category