Screening, 12 weeks of pregnancy: the norm, decoding
How to find out whether the fetus is developing properly, are there any deviations, how are the internal organs of crumbs formed? Answers can give (when the period to which your pregnancy approached is 12 weeks) ultrasound. Screening allows you to evaluate the development of the fetus, provides a clear picture of the genetic and chromosome features of the baby's future. This makes it possible to determine the presence or absence of anomalies.
Conduction of ultrasound on a 12-week period
Basically, the procedure is carried out in two ways: transvaginally (through the vagina with a special sensor) and transabdominally (through the abdominal skin). The latter is more common, and the first is not prescribed to all women in the situation, but only to some of them, in the following cases:
- if the placenta (or chorion) is low attached;
- if there is an itmiko-cervical insufficiency, and it is necessary to estimate its degree;
- if there are signs of inflammation of the cysts and appendages (to pinpoint the diagnosis), or the nodes of the uterine fibroids are very specifically located, and method No. 2 showed little information;
- When assessing the child's collar zone or measuring the right size, which is difficult to produce because the fetus is not positioned properly, or the subcutaneous tissue of the abdomen is very thick.
The study is as follows: a woman lies, bending her legs in her lap; the doctor inserts an ultrasonic sensor into the vagina, which is worn by a disposable condom for protection. Usually everything is done with great care, so the pregnant woman does not feel pain.
Transabdominal examination is done in the same position. All air between the sensor and the skin will not be displaced, therefore, incorrect results are possible. In order to reduce the probability of error as much as possible, use a special gel, which is applied to the abdomen. Gradually move the sensor over the stomach, so that you can see the organs of the crumbs, as well as the uterus and placenta of the mother. Ultrasound is absolutely safe for the fetus and does not cause any damage to it.
How to prepare for ultrasound
Preparation depends on the method. If transvaginal is used, it is recommended not to use 1 day before the test those products that are capable of causing fermentation: white bread, legumes, cabbage, peas. The intestine should be emptied, otherwise the gases there will prevent the examination of the uterus and fetus. If there is a feeling that the stomach is puffed, you can drink the drug Espumizan, which is harmless to the fetus.
Before the transabdominal test, drink half a liter of water 30 minutes before the start. It is necessary to have a full bladder, which will allow to inspect the fetus and assess its condition.
Child development on a 12-week period
Many basic organs of crumbs have already developed, and some small structures continue their formation. On average, a child's height is 80 mm, and weight - about 20 grams. Also, doctors note that the fetus eats such features:
- Cardiac contractions are more rapid than in the third trimester, and can be approximately 170 beats per minute;
- the child's face no longer looks like a tadpole, but acquires human features;
- You can see the eyelids, lobes, a little gun hair (on the spot of the formation of eyebrows and eyelashes);
- most of the muscles have almost developed, so the fetus moves all the time, and the movements are mostly involuntary and rather chaotic;
- crumb grimaces and squeezes his hands in the fists, on the fingers you can see the marigold;
- the kid has already developed a kidney and almost formed the intestine, red and white blood cells are seen in the blood;
- both hemispheres of the brain are fully formed, but "commands" while the spinal cord;
- you can see who it is: a boy or a girl, but since the fetus does not always lie as you want your mother and doctors, you can make mistakes, so you are more likely to talk about the field at the 16th week.
How to read the results?
Paper with the results of the study you get in your hands after the screening (12 weeks) is done. The analysis will be explained below.
Beginning with the third month it is already clearly visible, one child or not. Therefore, if two or more words are written in the "number of fruits" column, then this indicates that you will have twins (triplets, etc.). You can also find out whether identical fruits (twins) or twins (heterozygous) are identical.
This is the name of the part of the fetus closest to the birth canal. At 12 weeks, it can be anything: legs, head, or child at all will settle diagonally. Finally, the presentation is evaluated at the 32nd week of pregnancy. If the head is not located to the exit from the uterus, then all possible measures are taken to correct this situation.
Measurement of fetal size (or fetometry)
The decoding of ultrasound is needed to evaluate the parameters, but this should be done by a doctor who focuses not only on the numbers, but also on the overall situation of the pregnant woman. All norms are indicated by certain letters and numbers. Here are the main ones:
- BPD (BPD) - this abbreviation means the so-called biparietal size, ie, the distance of the head from one parietal bone. At a period of 12 weeks, ultrasound should show 21 mm BDP.
- The height of the baby is about 8.2 cm, the weight should not be less than 17-19 g.
- FML, DLB is the length of the thigh. The norm is from 7 to 9 mm.
- The collision space should not exceed 2.7 mm. By its size determine whether there are any serious illnesses. On average, it is approximately 1.6 mm.
- The term KTR (CRL) refers to the coccyx-parietal size, i.e. the maximum length from the head to the coccyx, the norm is 43-73 mm.
There are also other abbreviations:
- HUM (ДП) - the length of the shoulder.
- AC is the abdominal circumference.
- ABD (JJ) is the diameter of the abdomen.
- MS - the size of the heart.
- OG - head circumference.
For all these parameters, 1 screening during pregnancy allows the doctor-sonologist to determine how the baby's structures grow and develop. If the measurements made are less than the norm, then the total population estimates how they decreased: proportionally and simultaneously or not. If they do not coincide only a little, then there is no reason for panic. Perhaps, the deadline was incorrectly defined, and in reality it is only 11th week. And perhaps the baby has such growth because of his short parents.
Also find out whether there are any vices in the development of internal organs, whether there is a cord with a cord, what is the heart beat frequency (the norm is from 150 to 174 beats per minute), are there any deviations in the characteristics of the amniotic fluid.
Reading the conclusion of ultrasound, a pregnant woman may encounter such concepts as "polyhydramnion" and "oligohydramnion". What is it and is it worth it to be afraid? There is nothing terrible in these words. This is just a determination of the number of those waters in which the fetus is swimming: if more than necessary, polyhydramnion is fixed, if less - oligohydramnion. Often this indicates some violations: intrauterine infection (VUI), impaired renal function, central nervous system. They also watch if the water is cloudy. If so, then this is a clear indication of the infection.
The main rule for detecting abnormalities is not to panic, but to go to a specialist.
Can there be abnormalities on the part of the placenta?
The ultrasound shows where the "child's place" is attached, how mature it is, whether there are pathologies and other. The best option is to attach to the back of the uterus. But the placenta can "cling" to the anterior, and even to the bottom. In this case, it should not overlap the inner uterus. This condition is called chorion, or the central presentation of the placenta. In this case, monitor whether the situation will change, and if not, then conduct a cesarean section for delivery. If the pharynx is not completely blocked, this is called incomplete presentation; The births are carried out in the usual way.
If the placenta "sat down" near the exit (less than 70 mm), then this low presentation. Since it can become a threat of bleeding, the pregnant woman is recommended a less active regime. Then observe if the placenta rises up. If by 32-36 weeks of this happens, there will be no threat, and the woman will give birth in the usual way.
The maturity of the placenta at this time is 0. The "lobular" placenta is the second degree of maturity, and in such a situation it is necessary to consult a physician. Deposits of calcium salts are called calcinates. The norm is considered if they are present in the placenta of the first degree of maturity.
If a part of the "child's place" dies out, this is called a placental infarction. In this case, it is urgent to consult a doctor to find out the reason and prescribe the treatment, because if this happens later, the child will lack oxygen and the substances necessary for its development.
Cervix: condition, structure
At week 12, measure the size of the cervix, which should not be shorter than 30 mm. The longer it is, the better. If she is already very short, less than 20 mm, then the pregnant woman is hospitalized, and, possibly, will be used to treat surgery. The ovaries of the uterus should be closed, both external and internal.
Myometrium (or muscle condition) indicates whether there is a risk of miscarriage. If the diagnosis indicates that at this time there is hypertension of the uterus, then the woman is treated. Especially alarming are such facts as "petrification" of the abdomen, "pull-push" in the waist.
How to determine the term by ultrasound
Using special tables, the KTR calculates the gestational age. It can be that a similar function is built into the program of the ultrasound machine. Compare the timing - calculated from the last monthly and issued by ultrasound. If the difference is small (one or two weeks), then the exact time determined by the obstetrician is considered accurate. In the case of greater mismatch (more than 2 weeks) for a given period of time, determined by ultrasound.
Prenatal screening: what is it and how do
One should be especially careful when the pregnancy is 12 weeks. Ultrasound, screening - all these studies are designed to evaluate the development of the fetus. At the same time, ultrasound is first done, and then screening is also prescribed (depending on the indices). Conduct it if:
- Pregnant 35 years and older.
- Before this, dead children were born.
- When examining previous fetuses, intrauterine infection was detected.
- A child was born who had a chromosomal abnormality.
- It is established that such anomalies are present in the relatives of both parents.
Only in special centers do the screening (12 weeks). How do they do it? They collect all the tests: ultrasound, blood, external data. Evaluation of the study makes a geneticist, and attention is mainly drawn to the collar and these indicators: free β-hCG and RAPP-A. Basically, these markers are examined in a clearly established combination. If at least one of them has changed, this does not mean that the fetus has any pathologies.
So, when the screening for the 12th week of pregnancy is conducted, the characteristics of these markers are used. These are whey proteins. If they have deviations, the child will have genetic disorders. Free β-hCG is a subunit of human chorionic chorion (chorion is a germ), and PAPP-A is a pregnancy-associated protein A. To study these parameters, ELISA (enzyme-linked immunosorbent assay) is used.
HCG stimulates the synthesis of steroid hormones (in the placenta and the yellow body). Physicians have already found out that it is hCG that protects the fetus from rejection. Examining its level, you can make predictions for the further course of pregnancy. According to medical statistics, HCG is gradually increasing until the 10th week, and then remains approximately at the same level (from 5,000 to 50,000 IU / L) to 33 weeks, after which it may rise slightly.
1 screening for pregnancy is done from the 10 th to the 13 th week of the term. To calculate all the risks, take a lot of data: the date of ultrasound, CTE and TPV (the thickness of the collar space).
These analyzes are very important precisely for determining the existing pathologies in chromosomes. However, if the indications are slightly increased, do not worry and make hasty conclusions. You just need to turn to a geneticist who will tell you what to do next. Also, there is a possibility that the ultrasound is misread. Screening for a 12-week pregnancy can be repeated, for clarification, or the doctor will prescribe an invasive diagnosis that will more accurately determine a child's genetic set. Depending on the term, either a chorionic villus biopsy or amniocentesis is done.
If even 1 screening showed a very low risk of having chromosome pathologies in the fetus, then you should not abandon the examination, which takes place 4-5 months after pregnancy. In addition to HCG and AFP, the level of free estriol (triple test) is determined.
In order to determine the β-hCG and RAPP-A, blood is being screened. 12 weeks - already sufficient time for it to be possible to detect by biochemical analysis the presence (or absence) of abnormalities in chromosomes.
Conclusion by analysis
Depending on the results of the blood test, they reveal why the indices differ from the norm. Thus, screening for a 12-week pregnancy can reveal the following:
- Not one fruit, but 2 (3, etc.). More fruits - more hormone levels.
- Incorrectly fixed term of pregnancy. For each week of development of the child there corresponds some indicator that determines the exact age of the fetus.
- Presence of diabetes maternal.
- Great risk of miscarriage.
Are there any norms of indicators?
Of course there is! You can learn them by doing such studies as ultrasound, screening (12 weeks). The norm will become known after studying the data by the doctor. However, there are average medical indicators clearly established for each week of pregnancy. For example, β-hCG at 11-12 weeks should be from 200,000 to 90,000 mU / ml.
However, it should be borne in mind that the screening of a 12-week pregnancy gives, of course, very high, but still not 100% results, because every woman has her own peculiarities of the body, which are necessarily taken into account by the doctor. If the fetus is not one, then it is more difficult to diagnose it. Look at the indicators. If they are more than one and a half or two times, then we can conclude that the embryos are 2 or more. Each of the fruits has its own chorion and different hormone production. Therefore, the indicators are so high, and the future mother is sent to the ultrasound to confirm a multiple pregnancy.
Once the screening is done (12 weeks), the normative values are immediately checked against the received data to calculate if there are any pathologies. Physicians for these purposes use a special coefficient called MoM. It is calculated by a certain formula: the amount of the hormone that was established by the results of screening is divided into hCG (corresponding to the norm during this period of pregnancy). Should be a unit (this is ideal). Well, according to the results of all studies, it is judged whether to include a future mother in a risk group with chromosomal anomalies or not. It is worth noting that even if this happened, this is not a final verdict, but only one of the probabilities. Therefore, the remaining indicators are compared and only after that they draw some conclusions. Revise the entire screening of a 12-week pregnancy: ultrasound, hormones, TBI, can prescribe a second trial in the second trimester.
Protein RARP-A is responsible for the immunity of a pregnant woman, and it also helps the placenta work. Since the threshold limits are clearly established, its deviations are highly undesirable. The thing is that such "jumps" of the indicators speak not only of a possible miscarriage, but also of such terrible anomalies as Down syndrome, de Lange syndrome, etc. Normal figures are considered: from 11th to 12th a week - 0,7 - 4,76; from the 12th to the 13th week - 1.03-6.01.
Testimonials about research
Women who did screening (12 weeks), respond differently about it. Someone incorrectly determined the sex of the child. There is an explanation for this - the time is too short, it is finally possible to say who will be born: a girl or a boy, only at the 16th week. They also talk about different prices. Some people take tests for free, others pay between 1000 and 3000 rubles.
However, most mothers note that ultrasound and screening help to understand how the development of the baby is going on. Since now these procedures are mandatory, it is possible to diagnose and timely start treating existing diseases so that the baby is born healthy.