Screening during pregnancy. How many weeks do the first, second and third screening during pregnancy do?

How often do you need to do screening during pregnancy? Are they harmless? Norms and decryption of screening.

A healthy pregnancy is unthinkable without screening. But many fears of expectant mothers are connected with him. What will be the results? How to figure it out on your own? Will research to the baby harm? It turns out that screening is an absolutely harmless thing, if you do it on time and right. And for this you need to arm yourself with information.

What shows screening during pregnancy? How many screening is done for pregnancy?

Screening during pregnancy is a comprehensive examination, including ultrasound, blood test and some other procedures. It is prescribed to almost all women. Therefore, if you were sent to screening, do not worry that something is wrong with you. This procedure is standard. She is just called to help you and the doctor make sure that the pregnancy proceeds as it should. Typically, screening is carried out three times, once in every trimester.

1. The first screening shows the presence of pregnancy, the number of fruits, the correct finding of the embryo in the uterus, the presence of the main organs and systems, and the dynamics of development.
2. During the second screening, the doctor may already make sure that the baby has no development of development, whether nutrition enters him, if there are enough amniotic fluid.
3. The third screening not only diagnoses the condition of the baby, but also reveals important data. They will come in handy to the obstetrician who will take birth. For example, the doctor finds out in what presentation the fetus is in, in the head or gluteal, as well as seeing whether there is an indignation of the umbilical cord around the neck of the baby.

How many weeks of pregnancy do the first screening do?

In domestic obstetrics, it is believed that the first screening can be prescribed, starting from 11 weeks of pregnancy. Foreign colleagues do not agree with this statement. The fact is that this test requires an ultrasound examination. Ultrasound is able to heat the tissues in which the liquid is enclosed. Such tissues include, for example, the brain of the embryo. Ultrasound can harm him if the fetus is younger than 16 weeks. Therefore, the first screening is prescribed abroad only after this period.

But after 16 weeks, any study prescribed by a doctor is absolutely harmless. Try to make sure your screening passes after this deadline.

Decoding the first screening during pregnancy

The first screening is an ultrasound and a blood test from a vein. Do not beat the alarm if any result of your tests deviates from the norm. Screening is not a specific test that can make all diagnoses. This is a way to get a common picture that can give large errors. Therefore, the doctor never draws final conclusions on the basis of screening results. If he has any suspicions, he sends a woman for additional tests.

Ultrasound at this time can only give general information. But the floor of the future baby will most likely be called. With the help of ultrasound, you can establish whether there is a fetal egg, whether there is an embryo in it, whether it is viable. The doctor can see not only the correct position of the pens and legs, but also large systems of the body: brain, heart, blood system, intestines. The ultrasound specialist will measure the body length of the baby and compare it with the norm.

Biochemical blood test evaluates two indicators:

• chorionic gonadotropin. This is a substance produced by the shell of the fetus. With its help, pregnancy is diagnosed. In the first months, this indicator grows rapidly, reaches the maximum at 11-12 weeks, then gradually decreases, and in the second half of pregnancy remains at the same level
• pAPP-A protein is an indicator that the placenta surrounding the baby is functioning normally

What week of pregnancy is the second screening?

• The second screening is done for a period of 22 weeks. This time has been chosen because the fetus has already grown, and you can consider it in more detail. It is on this screening that some chromosomal abnormalities are most often revealed. Elena Berezovskaya, a researcher in the field of obstetrics and gynecology, explains this: “In the early stages it is impossible to see the malformations of the fetus
• Gent disorders can be diagnosed at 14 weeks, but smaller ones will become noticeable only in 19. At this time, up to 60% of developmental malformations can be detected. For example, it was noticed that in patients with Down syndrome, a collar area (this is a fold of the skin behind the neck) has a thickening. It can be seen in the fetus. This is one of the prognostic markers of the presence of trisomy 21 - Down syndrome "
• However, doctors are immediately stipulated that ultrasound has many errors. First of all, they depend on the human factor. The doctor must undergo a special test confirming that he has the right to conduct such a screening. Indeed, in the early stages of pregnancy, the baby is still very mobile. It is very difficult to catch and measure any parameter. And the prognosis of pregnancy may depend on these figures, and the decisions taken by the woman and her doctor

During an ultrasound of the second screening, the doctor measures the volume of the head, bones of the nose, the umbilical ring and a number of parameters. The so -called dopplerography measures the bloodstream in the uterus, so the doctor draws conclusions: whether the fetus is well supplied with the necessary substances. For the normal development of pregnancy, the embryo should be surrounded by a sufficient amount of amniotic fluid. This parameter is also measured on ultrasound.

Decoding and norms of the second screening

During 22 weeks, the baby’s growth can already be up to 28 cm, and the weight ranges in the region of half of the kilogram. The doctor measures the circumference of the head and tummy, the diameter of the chest, the length of the thigh and shoulder. It is worth remembering that at this age some anatomical features can manifest itself in the baby. Therefore, do not panic if some indicator deviates from the norm.

In the blood, another indicator is measured - estriol. This is the main hormone that is responsible for normal metabolism in the “mother - baby” system.

What week do I do the third screening?

The timing of the third screening is 32-36 weeks. During this study, the doctor tries to compose an approximate picture of future births. Is there a suspicion of the premature birth of the baby? This may indicate premature "aging" of the placenta or too small number of amniotic fluid.

Cardiotocography, or CTG, can be added to the usual research. In this case, the baby's heart rate is measured, as it changes at rest and during movements. From these data we can conclude whether the embryo hypoxia is experiencing.

Decoding and norms of the third pregnancy screening

During the last screening, doctors pay more attention to quantitative dimensions that characterize the viability of the fetus. At this time, you can not only register the heart rate, but also respiratory movements. The kid breathes measuredly and correctly, although it does not inhale the air. Moreover, if the embryo has a suspicion of hypoxia (oxygen starvation), it begins to instinctively breathe more often.

Screening for multiple pregnancy

Screening with multiple pregnancy is very complicated. This is due to the fact that many data have to be roughly divided in half. How these figures are actually distributed between two fruits are unknown. A blood test in this case almost never gives the right results. One and the same indicators are suitable for chromosome violation and multiple pregnancy.

When to do screening during pregnancy: tips and reviews

• “Do not panic if you received bad tests. Especially in private clinics. I heard that they specially persuade all the procedures several times to pull out the money "
• “I also have bad screening. I read on this topic, and realized that the most informative is an analysis through a puncture. True, it is very dangerous. The risk of miscarriage is 2%"
• “In the first screening, they told me that the probability is 1: 240, that the child is down. On the second - 1:45. She refused the puncture, the doctors poured dirt on me. Now my miracle is absolutely healthy in a bed. "
• “When I passed this analysis, I was tortured to listen to the rules. 5 days before, nothing red, no citruses, you can’t limit the protein, even vitamins, even vitamins. In general, diet. They tormented me, but the accuracy of the results is still 50x50 "
• “Do not believe poor forecasts. Better wait for childbirth. Then you will know for sure "

Video: DR. Elena Berezovskaya - ultrasound as part of prenatal screening