Compulsory studies in late pregnancy include screening for the 3rd trimester . It helps to establish the condition of the fetus, assess the rate of development of the future baby, the functioning of its organs and systems, eliminate vices in the presence of suspicion of them.
Screening for the 3rd trimester - what is it?
The term screening for the third trimester is used to designate a set of diagnostic procedures in which the condition of the fetus and maternal organs is determined. At the same time the basis of screening is ultrasound. During it, doctors set the parameters of the physical development of the fetus, evaluate the functioning of its internal organs and systems. Carefully study those areas of a small organism where there could be a violation.
Together with ultrasound, screening for the 3rd trimester includes cardiotocography and dopleromerism. These studies help determine the condition of the circulatory system of the baby, the features of the heart. At their carrying out the doctor carries out calculation of quantity of palpitations, inspects large blood vessels, a placenta, estimating supply of a fetus by oxygen and nutrients. If necessary, some pregnant women may be assigned a biochemical blood test.
What does the screening show for the 3rd trimester?
Ultrasound of pregnancy (3 trimester) establishes the condition of the fetus, the speed of its individual development, excludes the presence of pathology. In carrying out this set of studies, doctors determine:
- length of the body, the size of the fetus, comparing them with the norm at this time of pregnancy;
- the state of the vessels of the placenta, the rate of blood flow in this organ;
- functioning of the main organs and systems of the future baby.
Cardiotocography of the fetus
The screening for the 3rd trimester, which is scored exclusively by a doctor, includes a karyotiocography (CTG). Its purpose is to assess the degree of saturation of the baby's blood with oxygen. In this case, the physician registers the number of palpitations of the fetus at rest and during the movement . The registration of these indicators is carried out using ultrasound.
The heartbeat of the baby, the number of beats per minute, the acceleration or deceleration depending on the test being carried out is displayed on the screen of the device. The doctor compares the obtained data with the indicators of the norm and draws a conclusion. In cases of severe oxygen starvation, which affects the life of the fetus, early delivery is possible.
Ultrasound screening 3 terms
With such a study as ultrasound of the fetus, the trimester, the doctor evaluates the indicators not only of the physical development of the baby, but also the functioning of individual organs and systems. During the procedure, the doctor carefully examines:
- cardiovascular system;
- brain;
- veins of the cavity of the skull;
- abdominal cavity organs;
- genitourinary system.
Special attention is paid to the placenta. The doctor determines:
- condition of placental blood flow;
- localization of a child's place;
- thickness of the placenta;
- degree of maturity of the placenta .
About when to do ultrasound 3 trimester, pregnant women learn in advance. This study at a later date involves the examination of the female reproductive system. Doctors are interested in the state of the uterine neck, its walls, the degree of maturity (readiness for swift delivery). At the same time, the values obtained are compared with the norm values, and if there are violations, additional studies are assigned. In the course of these, the causes of violations are established.
Fetal dopplerometry in the 3rd trimester
Doplerometry in the 3 trimester suggests an assessment of the nature and speed of blood flow, patency of the blood vessels of the placenta. This study helps doctors determine the degree of oxygen saturation of the blood. On the deviation of indicators from the norm, doctors can at an early stage reveal the pathology of the cardiovascular and nervous systems. The study is performed on an ultrasound machine and for women it is practically the same as for an ordinary ultrasound examination.
Triple Screening Test
In this study, venous blood serves as a material for assessing the state of the maternal organism. With triple biochemical screening, determine the content of such substances as:
- alpha-fetoprotein ( AFP );
- human chorionic gonadotropin (hCG);
- free estriol.
This study is assigned only to those pregnant women who, in previous screening, did not meet the standards. When the trimester is screened, doctors determine the current state of the maternal organism, detect abnormalities in a timely manner, prevent complications of the pregnancy process, and take appropriate measures.
How is the third screening done during pregnancy?
About how ultrasound is carried out for the 3rd trimester, women are known from previous studies, and studies such as CTG and dopplerometry can cause fear in them. When conducting CTG:
- The woman is on the couch.
- Several sensors are installed on her abdomen - ultrasonic and strain gauge (determines the uterine contractions).
- The doctor records the fetal heart rate. The procedure lasts 30-60 minutes.
Dopplerometry of pregnant women is carried out as follows:
- The woman assumes a horizontal position.
- The doctor applies a gel to the surface of her stomach.
- Moving the sensor over the surface of the skin, the doctor examines the large blood vessels, assessing the rate of blood flow in them. According to the sensations of the most pregnant, the procedure does not differ from usual ultrasound.
Screening for the 3rd trimester - dates
Knowing about the upcoming study, pregnant women are often interested in the doctors as to when they are screening the 3 trimester. The ideal time for its implementation is 32-34 weeks of gestation. All the researches of a woman seldom manage to pass in one day, therefore this time corridor is established. If a biochemical test is prescribed, then it is necessary to pass it in the above terms. At the same time, ultrasound can be screened early. It should be noted that the screening of the 3rd trimester, at what time it is spent - depends on the specific situation.
Screening for the 3rd trimester - preparation
Before taking the tests in the 3 trimester of pregnancy, a woman should be properly prepared for them. This will eliminate the distortion of the results, the data obtained will objectively reflect the state of the small organism. However, not all studies require preliminary preparation. So, ultrasound and dopplerometry can be carried out almost at any time. The only condition for performing ultrasound is an empty bladder.
In order to obtain accurate results of CTG, doctors recommend that before the study eat something sweet. Increase in glucose in the blood will increase the motor activity of the baby. As a result, doctors will be able to record more fetal movements, under which the cardiovascular system will be evaluated. The procedure itself will take less time.
When biochemical screening for the third trimester of pregnancy is scheduled, the expectant mother is warned about the need to follow a diet. Blood sampling is performed on an empty stomach, and 3 days before the analysis, the following are excluded from the diet:
- roast;
- salty;
- smoking;
- pickled vegetables;
- products that provoke allergic reactions - cocoa, citrus, chocolate.
Screening for the 3rd trimester - normal rates, table
Only doctors should evaluate the results of the research. This takes into account all the features of a particular pregnancy. Minor deviation of indicators from the established norms is not a violation, but may indicate the need to monitor a certain parameter. Ultrasound 3 trimester, the norms, the interpretation of which should be evaluated by doctors, allows you to determine the existing deviations. Below in the tables we give the values of the norms of the main parameters of screening for the 3rd trimester.