The first weeks of pregnancy are a very important time for both the expectant mother and her baby. During this period, the child starts laying down all vital organs and systems. In order for doctors not to miss a single pathology, the first screening is carried out.
Research essence
Prenatal examinations are very important procedures that have appeared in Russia relatively recently. It was developed by specialists from the Ministry of Health, who were concerned about the high maternal and infant mortality rate. Quite often, various "Mute" pathologiesthat develop during pregnancy or in a mother or her baby.
Screening doctors call specific "sifting". In this case, all women with any pregnancy pathologies are identified. However, pathological conditions do not always appear in the earliest weeks. Quite often it happens that such pathologies appear only in the 2nd trimester of pregnancy.
To determine the term, doctors do not use months, but obstetric weeks. They divide the entire period of carrying a baby into several equal periods, which are called trimesters. Each of them consists of 12 obstetric weeks. The first screening is done in the 1st trimester of pregnancy.
It is important to note that the obstetric term does not correspond to the gestational age that expectant mothers calculate.
They usually consider the first date of pregnancy from the first calendar week from the date of conception. In this case, 12 obstetric week corresponds to 14 calendar week.
For the entire period of pregnancy, you need to spend 3 such research complexes. They are held every trimester. The complex of studies carried out in each period of pregnancy is different. This is due to the daily changing hormonal background in a pregnant woman, as well as the physiology of the developing fetus.
A comprehensive screening study includes the delivery of some biochemical tests and the mandatory passage of an ultrasound scan. Combined methods provide more accurate results. The assessment of the results obtained is carried out by an obstetrician-gynecologist. If, after the study, the doctor cannot exclude the presence of any genetic diseases in the future mother, then he will refer her to a geneticist for consultation.
Dates
Usually, the first screening is done at 11-13 obstetric weeks of pregnancy. The timing of the diagnostic complex can be shifted by 7-10 days for medical reasons. The exact timing of the first screening must be determined in conjunction with the obstetrician-gynecologist who observes the pregnant woman during the entire period of pregnancy.
The duration of the first screening may vary. Such diagnostics usually take several days in time. A couple of weeks may pass between the delivery of biochemical tests and an ultrasound scan. This is a very normal situation and is quite common. Any changes to the dates of studies must be agreed with the attending physician.
This period was not chosen by chance: a new stage of pregnancy begins, which is called fetal. The doctors called the preceding time embryonic. At the end of the twelfth week of pregnancy, doctors no longer call the baby an embryo, but a fetus.
Who shouldn't miss the study?
Currently, doctors recommend such a study to absolutely all pregnant women, without exception. This is a preventive medical procedure that allows early detection of dangerous organogenesis pathologies in fetuses.
The first 12 obstetric weeks - time of active growth and development of all internal organs of the baby. The impact of any external factors can lead to the formation of pathologies. Only comprehensive diagnostics will allow them to be identified. Also at this time, it is possible to identify concomitant diseases of the internal genital organs in the mother.
Doctors recommend that expectant mothers be screened in the first trimester, in whom conception occurred after their 35th birthday. It is also important to conduct such a complex of studies for all pregnant women with a burdened family history of genetic and chromosomal diseases.
There is also a high age-related risk for the development of these pathologies. In this case, the first screening should be carried out for women who become pregnant after 40 years. Expectant mothers, who often have spontaneous miscarriages or have suddenly interrupted previous pregnancies, should also not miss such a complex of diagnostics.
Doctors recommend screening in the first weeks of pregnancy for expectant mothers who have severe concomitant diseases of internal organs.
Such a complex of diagnostics is also necessary for pregnant women suffering from diabetes mellitus. The most dangerous is its insulin-dependent variant.
If the expectant mother takes hormonal or glucocorticosteroid drugs constantly, screening is required. These agents can have an adverse effect on fetal organogenesis. If taking these medicines cannot be canceled for the entire period of bearing the baby, it is imperative to monitor the course of pregnancy.
The first screening must be carried out for expectant mothers who already have children suffering from genetic or severe somatic diseases. An increased genetic risk is the reason for the mandatory passage of such a complex of research.
Also, screening of the first trimester is mandatory for pregnant women who abuse alcohol or continue to smoke. In this case, the risk of the formation of dangerous intrauterine pathologies increases several times. You should also undergo screening if the expectant mother and fetus different Rh factor.
How to prepare properly?
Proper preparation is essential to obtain reliable test results. Before taking biochemical tests, doctors prescribe expectant mothers to follow a lipid-lowering diet. It excludes the use of fatty and fried foods. All cholesterol-rich foods are also banned. Saturated fats that enter the bloodstream through food can cause inaccurate results.
A lipid-lowering diet should be observed before the first screening 5-10 days before the study. Dinner on the eve of going to the laboratory should be made as light as possible, but nutritious and high in calories. It is better to have protein foods as the basis of food. You can supplement them with any cereal side dish.
You should not eat a lot of vegetables and fruits 2-3 days before the screening ultrasound. They can cause strong gassing. This will significantly complicate the research. Gas-swollen intestines often cause echo-negative phenomena.
If the expectant mother still continues to smoke while carrying the baby, then it is better not to do this before going to the laboratory. The nicotine in cigarettes can skew the results. Any drinks that contain alcohol are also excluded.
You should go to the laboratory fasting... Doctors recommend taking tests in the morning, immediately after waking up. Biochemical tests performed in the evening are often unreliable. Do not eat breakfast before going to the laboratory. The last meal is dinner.
Before passing laboratory tests, doctors allow drink some water. You should not drink a lot before an ultrasound scan in early pregnancy. This can lead to severe filling of the bladder. Preliminary fluid intake may only be required when performing a transabdominal ultrasound.
Strong physical activity should be avoided before the first screening. Expectant mothers should remember that even the usual household activities during pregnancy can lead to distortion of the results. Doctors note that the usual cleaning of the apartment on the eve of a trip to the laboratory can lead to unreliable test results.
Severe psychoemotional stress should also be excluded before the study. Expectant mothers should not be nervous or worried not only before the first screening, but throughout the entire period of pregnancy.
Prolonged stress leads to disruption of the work of internal organs, which ultimately leads to a distortion of the results obtained.
How is it going?
Screening is divided into several stages. Usually the first one is visit to the laboratory. You can take tests both in a regular women's clinic and in a private one.
In the first case, you need a referral for tests, which is issued by an obstetrician-gynecologist for consultation. This medical form contains the patient's personal information, as well as the estimated gestational age.
The next stage of screening is ultrasound... Early on, this research can be done in different ways. If the pregnant woman does not have any medical contraindications, a transvaginal examination is performed. For this, a special ultrasonic sensor is used, which is inserted into the vagina.
There are a number of medical contraindications to conducting a transvaginal examination:
- These include any acute diseases of the internal genital organs in the mother.
- Acute colpitis or vaginitis are reasons for choosing an alternative ultrasound method.
In this case, already transabdominal study. To carry it out, the doctor uses a special ultrasonic sensor, which he guides over the belly of the future mother. In this case, the image appears on a special screen - a monitor. During the study, the expectant mother can see her future baby with a doctor. The child's dad may also be present at this examination.
To obtain better visualization, ultrasound specialists use a special diagnostic gel. It is applied to the skin of the "pregnant" tummy just before the procedure. Future mothers should not be afraid of the aggressive effects of this gel. Its composition is completely hypoallergenic.
Ultrasound examination is performed on a special couch. The expectant mother is laid on her back. In the early stages of pregnancy, it is possible to conduct a study in this position. Only in those situations where the expectant mother has a pathological bend of the uterus, it may be necessary to turn to the left or right side.
If the study is carried out in a regular clinic, then the woman should definitely bring a towel with her. It will be required in order to lay on the couch.
You should also bring along special paper handkerchiefs or napkins. They will be required in order to wipe the remains of the diagnostic gel from the abdomen.
What does it show?
During the first screening, doctors examine several important biochemical markers. Any deviations from the norm must be assessed by an obstetrician-gynecologist.
With multiple pregnancies with twins or triplets, biochemical indicators at this stage of pregnancy may be slightly different.
About PAPP-A
This specific biochemical marker is used to assess the risk of genetic and chromosomal abnormalities. Pregnancy associated plasma protein A or PAPP-A also makes it possible to identify these diseases at fairly early stages of their formation. This substance is produced by the placenta during fetal development.
The delivery of this analysis is obligatory for future mothers who have conceived a baby after 35 years... Also, such a study should be carried out by women who have been diagnosed with HIV infection or parenteral hepatitis B and C.
Normal values of this indicator significantly depend on the duration of pregnancy. For a period of 12 obstetric weeks, this criterion is 0.7-4.76 IU / ml. Next week, the rate of this indicator is 1.03-6 IU / ml.
If during this period of pregnancy the values are significantly lower than normal, then this may indicate the presence of genetic pathology.
In this situation, the doctor will definitely send the expectant mother to undergo additional diagnostics.
About human chorionic gonadotropin
During the study, a special b-fraction of this substance is determined. This hormone is also called hCG. During the entire period of pregnancy, the concentration of this substance changes. In the first weeks it is at its maximum. The content of gonadotropin is significantly reduced immediately before childbirth.
The gonadotropin rises quite strongly after conception occurs, when the ovum and sperm have merged. In this case, the chorion begins to produce the first portions of hCG practically in the first hours after pregnancy.
The concentration of this substance in the blood increases significantly with multiple pregnancies, as well as in some pathological situations.
In the second trimester, this indicator stabilizes and practically does not increase. This situation persists until delivery. The decrease in the concentration of hCG in the last trimester of pregnancy is physiological. This is necessary for natural childbirth.
For ease of use, doctors have created a special table in which they entered normal hCG values. It is used in their daily work by obstetricians-gynecologists. Below is the the table in which the normal indicators of gonadotropin are entered during the first screening:
About ultrasound
It is impossible to imagine the first screening without ultrasound examination. To assess intrauterine development, doctors have developed several criteria. They are different in each trimester of pregnancy.
The first weeks of pregnancy are quite early. The frequency of technical errors and errors at this time is quite high.
During the first screening, an experienced ultrasound specialist can even determine the sex of the child. If the future boy or girl does not deviate from the ultrasound sensor, then they can be seen quite clearly.
Determine the gender of the future baby up to 12 weeks almost impossible... The risk of errors in this case is very high.
About the coccygeal-parietal size
The coccyx-parietal size (CTE) is very important in assessing the intrauterine development of the fetus. This criterion is necessarily compared with the weight of the baby and the gestational age. There is a certain pattern - the "older" the fetus, the larger and the coccygeal-parietal size.
During the first screening, the normal CTE values are as follows:
- at week 10 - 24-38 mm;
- at 11 weeks - 34-50 mm;
- at week 12 - 42-59 mm;
- at 13 weeks - 51-75 mm.
Future mothers begin to worry strongly if this indicator deviates from the norm. You shouldn't panic. Small deviations of this indicator may not be due to the presence of some pathology. A small CTE can be in a miniature baby. This symptom is especially often manifested in babies whose parents are also short.
About biparietal size
To calculate this indicator, the linear distance between the two parietal bones is measured. Also, doctors call this parameter simply - "Head size". Evaluation of deviations from the norm of this ultrasound allows you to identify dangerous fetal pathologies, some of which may even lead to spontaneous abortion.
At 11 weeks of intrauterine development of the fetus, this figure is 13-21 mm. By week 12, it changes to 18-24 mm. After a week, this figure is already 20-28 mm. Any deviations from the norm can become a manifestation of emerging pathologies.
A too large fetal head with a narrow mother's pelvis may be an indication for a caesarean section. However, the need for surgical treatment is established only in the 3rd trimester of pregnancy.
In such a situation, doctors recommend that you go through two more sets of diagnostics.
About the thickness of the collar space
Also, doctors call this indicator the size of the cervical fold. In appearance, it is a rounded formation. It is located between the neck and the upper surface of the fetal skin fold. It accumulates fluid. This study is carried out precisely in the first trimester of pregnancy, because the cervical fold is well visualized.
Collar thickness gradually decreases... Already by the 16th week of pregnancy, this formation is practically not visualized. Normal values at 12 obstetric week of intrauterine development are 0.8-2.2 mm. After a week, this value is already equal to 0.7-2.5 mm.
A change in this indicator is usually a manifestation of trisomies. These dangerous pathologies are manifested by various genetic pathologies.
This is how Edwards and Patau syndrome, Down's disease, and Shereshevsky-Turner syndrome can manifest. Trisomy is a pathology when, instead of a binary set of chromosomes, another "extra" third chromosome appears in the genetic set.
About the nasal bone
This bone formation is a very important criterion for the ultrasound diagnosis of the first screening. The nasal bone is elongated, has an elongated quadrangular shape. This is a pair education. During the study, the doctor necessarily measures the length of this bone element. At 12-13 weeks of intrauterine development, the nasal bone is 3.1-4.2 mm in size.
If this bone element is absent in the baby, then this may speak about the presence of genetic or chromosomal pathology. A decrease in the length of the nasal bone is also a consequence of emerging diseases.
At 10-11 weeks, an experienced ultrasound specialist can only determine the presence or absence of this bone element.
About heart rate
This important parameter is determined from the first screening and in all other weeks of pregnancy. If the heart rate deviates from the norm, then this indicates a problem in the fetus. Significant deviations of this indicator can also occur with a very dangerous pathology - placental insufficiency.
Scientists have found that the fetal heart muscle begins to contract in the third week after conception. You can determine this sign already from the 6th obstetric week. For a correct assessment of this indicator, a correlation is required between the heart rate of the fetus and its mother.
At the 10th week of pregnancy, the rate of this indicator is 160-179 beats per minute. At 11 weeks - 153-178. By the 12th week of pregnancy, this indicator changes to 150-174 beats per minute.
In the first 4-6 weeks of intrauterine fetal development Heart rate increases by 3 beats daily. With the help of high-precision ultrasonic equipment, this indicator is perfectly determined. For the study, ultrasound specialists use a special mode of heart examination, which is called a four-chamber. It allows you to see the atria and ventricles.
If during the screening ultrasound, various abnormalities were detected, Doppler sonography may be required. It helps to identify abnormal blood flow in the heart valves.
Such regurgitation may indicate the formation of a dangerous heart defect. To correct the violations that have arisen in this case, it may be necessary to carry out a surgical cardiac operation immediately after the birth of the baby.
The size of the brain is a very important parameter under study. At this stage of intrauterine development, doctors still cannot assess all intracerebral structures. The symmetry of their structure indicates the normal development of the brain.
Experienced ultrasound specialists also determine the location and structural features of the chorion.
Assessment of the structure of the cervix is a very important indication. During an ultrasound examination, doctors also assess the size and structural features of the internal genital organs of the expectant mother.
Assessment of uterine blood flow is a very important indicator that is investigated during the first screening. Any pathologies that are detected at this stage are very important in the further prognosis of the development of pregnancy. A decrease in uterine blood flow can lead to a serious complication - the development of fetal hypoxia.
The increased tone of the uterus is an extremely unfavorable condition. If doctors find this symptom during pregnancy, then they, as a rule, offer the expectant mother to be hospitalized in the hospital "for preservation." There she will be provided with the necessary treatment, which will help eliminate hypertonia and normalize placental blood flow.
About MoM
Multiple of median or MoM is a specific indicator that is used by doctors to identify genetic abnormalities in the fetus. It is calculated using a special computer program.
The calculation requires the introduction of the initial indicators of the expectant mother, as well as the results of the obtained results of the ultrasound examination.
Doctors consider the indicator to be the norm from 0.5 to 2.5. For the correct interpretation of the obtained indicator, doctors also take into account a number of concomitant diseases in a pregnant woman, her race, as well as other necessary parameters. Deviations from the norm are manifestations of genetic or chromosomal pathologies.
Genetic screening
If, after screening, doctors determine any signs of genetic diseases in the baby, then the expectant mother must be sent to a geneticist for consultation.
It will also not be superfluous to visit this doctor for women whose close relatives have any chromosomal diseases. A burdened history of various congenital pathologies is a significant reason for contacting family genetics for consultation.
For example, the wording "The risk of developing Down's disease in a baby is 1: 380" says that out of 380 healthy babies, only one child will have this congenital disease.
Obstetricians and gynecologists distinguish several high-risk groups. Women who fall into this category should definitely be referred to a geneticist for consultation. Experts consider the ratio 1: 250-1: 380 to be a high risk of developing pathology.
Doctors identify several of the most common chromosomal pathologies, which often develop in the first trimester of pregnancy:
- Patau syndrome is one such disease. It is characterized by trisomy 13 pairs of chromosomes.
- An additional 3 chromosome in 21 pairs leads to the development of Down's disease. In this case, in the genetic set of the baby, instead of 46 chromosomes, 47 appears.
- The loss of one of the chromosomes in the karyotype of the baby leads to the development of a very dangerous genetic disease - Shereshevsky-Turner syndrome. This pathology is manifested by a pronounced lag of a sick child in physical and mental development from their healthy peers.
- The presence of an additional third chromosome on pair 18 is a sign of Edwards syndrome. This pathology is extremely unfavorable. Usually it is combined with the formation of many different congenital disorders and malformations. In some cases, such a congenital disease may be life-threatening.
Babies who develop Edwards or Patau syndromes very rarely live up to a year. Babies with Down's disease live much longer. However, the quality of life of these babies suffers significantly.
Such "special" children definitely need careful care and constant attention from their parents.
Genetic screening is performed In all countries. At the same time, only the list of biochemical analyzes included in the survey differs. It should be noted right away that the indications for termination of pregnancy differ in different countries. This situation is largely due to the better socialization of people with genetic syndromes abroad.
Genetic diseases are quite dangerous pathologies. Making such a diagnosis only based on the results of the screening is not done. To clarify chromosomal pathologies, a geneticist may prescribe additional studies for a pregnant woman. Some of them are invasive.
To obtain the genomic set of the fetus, chorionic biopsy. In some situations, puncture of the amniotic bladder is required. This test is also called amniocentesis. Also, during this diagnostic procedure, specialists take the amniotic fluid for analysis.
Placental biopsy is an invasive study necessary to exclude a number of combined pathologies of the membranes. For this examination, doctors use special puncture needles that pierce the skin of a pregnant woman. There is a risk of a secondary infection during such a procedure. It is worth conducting this study only for strict medical reasons to exclude conditions that are life-threatening to the fetus.
With the help of cordocentesis, doctors can also identify various pathologies in a baby. For this, the umbilical cord blood. The timing of such a procedure may be different. Often the need for such an invasive examination is collectively accepted.
Many doctors believe that the risk of developing genetic pathologies is directly related to age.
Women who decide to conceive a baby after 40 years should think very seriously about such a decision. Doctors quite often recommend that they contact for a consultation with a geneticist even at the planning stage of pregnancy.
If, during the screening, the doctor established signs of dangerous genetic diseases, then he must definitely warn the future mother about this. Pathologies incompatible with life are absolute indications for termination of pregnancy. The final decision on this issue remains with the woman.
Decoding the results
It is impossible to interpret only one analysis or ultrasound. To establish a diagnosis, a mandatory comprehensive assessment of all received analyzes and an ultrasound conclusion is required. The interpretation of the results is carried out by the obstetrician-gynecologist observing the pregnant woman. In complex clinical cases, a medical consultation may even be required.
Edwards syndrome is also accompanied by a decrease in the concentration of PAPP-A in the blood. Also, this pathology is characterized by a deviation from the norm of chorionic gonadotropin. This disease occurs in babies with a frequency of 1: 8000. In the first screening, it is quite difficult to identify combined congenital anomalies of internal organs. They are detected in the fetus already during the 2nd and 3rd screenings.
The main indicators of the ultrasound scan help doctors to identify various pathological conditions in the fetus at the earliest stages of their formation. Thus, an increase in the biparietal size can be a sign of an emerging hernia of brain tissue or a growing neoplasm. As a rule, such pathologies are considered incompatible with life and are indications for termination of pregnancy.
Hydrocephalus of the brain in the fetus is also manifested by an increase in biparietal size. To assess this pathological condition, dynamics is necessarily assessed. For this, doctors prescribe several repeated ultrasounds, which are required to be performed in the next trimesters of pregnancy. The negative dynamics of the development of this condition can lead to the need termination of pregnancy and the urgent appointment of drug treatment.
Experienced specialists during the first screening can also identify various defects in the structure of the neural tube. Doctors call this pathological condition meningoencephalocele. Cornet de Lange syndrome is a very rare genetic disorder that is incompatible with life.
Umbilical hernia is another dangerous congenital malformation, which is accompanied by multiple disorders of the internal organs. In this condition, they fall into the region of the anterior abdominal wall of the fetus. This pathology is extremely unfavorable.
Deviations from normal values in biochemical analyzes are very important signs of the development of genetic diseases. A decrease in PAPP-A is quite often manifested in Down's disease. This pathology, identified at this time of intrauterine development of the fetus, can become a clear sign of a spontaneous miscarriage or spontaneous abortion.
Smith-Opitz syndrome is one of the dangerous genetic diseases that can be suspected during the first screening. It is due to strong mutations in the genetic apparatus. This pathology is characterized by combined disorders of cholesterol synthesis, pathologies of the nervous system, as well as orthopedic disorders. This disease does not occur so often - with a probability of 1: 25,000.
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An increase in gonadotropin is also a consequence of the emerging pathologies in the fetus. Elevated hCG can also be found in some diseases that appear in the expectant mother during her pregnancy. Usually, severe forms of diabetes mellitus, as well as severe toxicosis, lead to an increase in gonadotropin.
Decreased hCG is quite often a sign of the pathological course of pregnancy. This condition can also develop with placental insufficiency. This pathology can lead to severe fetal hypoxia. To assess the risk of the formation of various diseases, doctors use a special program called PRISCA.
After carrying out such a computer diagnostics, the doctor conducting this study issues a conclusion to the future mother. It indicates all identified pathologies, as well as the risk of developing genetic diseases.
What can affect the results?
If pregnancy occurred as a result of in vitro fertilization, then the indicators of biochemical tests may be different. In this case, the interpretation of the results must be done very carefully:
- Diagnostics is carried out for each of the kids. In this case, chorionic gonadotropin can exceed normal values by 20%, and PAPP-A, as a rule, decreases.
- Excessive excess weight in the expectant mother is another factor that can lead to a distortion of the results obtained. In this condition, all studied hormones increase. If the expectant mother has signs of body weight deficiency, then in this case, on the contrary, the concentrations of biologically active substances are significantly reduced.
- Multiple pregnancy is a reason for a more thorough interpretation of the results. In this case, hCG rises significantly. At the same time, the PAPP-A level can be maintained within the normal range. An isolated assessment of biochemical markers without ultrasound in pregnancy with twins or triplets should never be performed.
- The uncontrolled course of diabetes mellitus leads to metabolic disorders. Ultimately, this can lead to deviations from normal values in biochemical analyzes.
How much does research cost?
You can pass the first screening in a regular clinic. However, not all medical institutions have a good material and technical base and equipment. It often happens that many biochemical studies can not be performed in a regular antenatal clinic. This problem is especially acute in settlements where few residents live.
Ultrasound examination is also a mandatory component of the first screening... In some cases, it is better to conduct such a survey on expert level equipment. Unfortunately, not all medical institutions are equipped with such devices. An ultrasound scan using expert class equipment is required for pregnant women with serious pregnancy pathologies.
Future mothers suffering from severe diseases of internal organs can be referred to the perinatal center. Usually pregnant women with various heart defects are sent there.
In this situation, the risk of developing various defects of intrauterine development in their future babies increases many times.
The first screening can also be done at a licensed private clinic. The passage of the research complex in this case is usually very comfortable. All consumables are already included in the cost of screening.
The cost of such a complex of diagnostics can be different. It also varies significantly from city to city. The future mom will have to pay for biochemical tests from 1200 to 3000 rubles. With the expansion of the complex, the cost may increase by 1.5-2 times.
The price of a screening ultrasound scan is usually 2000-5000 rubles. The cost of the procedure largely depends on the qualifications of the specialist who conducts the study.
The following video review will tell you about what you can see at the first screening.
