Trimester 2: Pregnancy screening. Deciphering the results, which shows the timing of the

2024 Author: Priscilla Miln | [email protected]. Last modified: 2023-12-16 00:21

During the period of bearing a child, a woman should be especially responsible for her own he alth. Now doctors recommend each patient to donate blood and undergo ultrasound at certain periods. The doctor compares the results obtained with the norms of 2 screenings during pregnancy. After that, the patient can be prescribed treatment. What is the best time for screening in pregnancy 2? In the article, we will consider the answer to this question.

When screening is scheduled

During pregnancy, the expectant mother must be observed by a doctor. At what week 2 is pregnancy screening recommended? A woman can donate blood for research from 15 to 20 weeks. It is believed that during this period it is possible to most accurately determine the level of hormones in the body. But the most optimal time for screening will be the period from 16 to 18 weeks. During this period, it is possible to determine the biochemical composition of the blood as accurately as possible. The information content of the study will be veryhigh.

When is the best time to do 2nd pregnancy screening? The ideal time for an ultrasound examination is from 19 to 24 weeks. If doctors have any concerns, screening can be rescheduled to an earlier time. As a rule, the doctor first directs the expectant mother to donate blood, and after receiving the results of the study, he recommends an ultrasound scan. During this period, you can already see the baby well and understand how it develops in the womb.

With a favorable course of pregnancy, the doctor sends his patient for an ultrasound scan in the period from 19 to 22 weeks. If during the study any abnormalities are found in the fetus, then the woman may be assigned a second scan. In some cases, the expectant mother may be assigned a consultation with a geneticist or other narrow specialists.

Why screening

This procedure is assigned to every woman carrying a child, even if she has absolutely no complaints about her he alth. Deciphering 2 screening during pregnancy is done by a doctor who, in case of unfavorable test results, prescribes additional studies. Doctors pay special attention to women in one of the risk groups:

• Drinkers and drug users.
• Having a burdened gynecological history.
• Pregnant for the first time over the age of 35.
• Survivors of early infectious diseases.

Particular attention is paid to the fair sex, who hadoncological pathology was detected for a period of more than 14 weeks. At risk are families in which future parents are in close consanguinity. Why do you need 2 screening during pregnancy? To notice deviations from the norm in the development of the fetus in time and correct them.

Also at risk are expectant mothers who have already had children with genetic abnormalities. Earlier screening may be considered for women whose previous pregnancies ended in miscarriage. At risk are expectant mothers whose close relatives suffer from genetic pathologies. Physicians should be especially careful to monitor the test results of any woman who has any problems during the first screening.

Preparing for the study

It is better to schedule blood donation in the early morning so that too long a lack of breakfast does not cause dizziness. What does 2 screening during pregnancy show? Based on its results, one can judge the development of the fetus and the he alth of the expectant mother. Some women are so worried before screening that they cannot sleep. This cannot be allowed. The main preparation that is needed before taking tests is peace of mind. The expectant mother should take this seriously, because she should not worry.

You need to donate blood strictly on an empty stomach. The last meal should be 6-8 hours before the study. If you eat shortly before donating blood, then the results may not be entirely reliable, which will only add to the experiences of the expectant mother. The day before, it is not recommended to eat any foods that can cause allergies. It is also undesirable to eat fatty, sweet, starchy foods. Before the study, it is advisable to drink some clean water.

Ultrasound can be performed at any time. Although the fullness of the intestines and bladder cannot affect the results, it is advisable to empty them. This is due to the fact that during the study, a woman may want to use the toilet, she will not feel very comfortable.

Ultrasound in the second trimester

After examining the indicators of 2 screenings during pregnancy, the doctor issues a conclusion to the expectant mother. Despite the fact that everything is detailed in it, for a person who does not understand medicine, these data will hardly be informative. Usually, an ultrasound doctor does not make a diagnosis, but recommends that a woman visit her local gynecologist.

If waiting too long for a consultation, the patient may inquire about the results of the perinatal screening. Do not forget that in the case when deviations are noticed in only one indicator, the doctor will not judge the presence or absence of pathology by it. All babies in the womb develop differently, so a woman should not worry about minor deviations from the norm. If the doctor notices that the child has a suspicion of a pathology, he will immediately report this.

The doctor can determine the sex of the baby at the 2nd pregnancy screening. But this can only be done if the baby lies correctly. If the child covers his genitals orturned to the booty specialist, it will not be possible to determine the sex during this ultrasound examination. In this case, parents can only come to terms with this fact and wait for the next screening, which is prescribed in the 3rd trimester. But sometimes expectant mothers want to know the sex of the baby so much that after a while they go for an ultrasound again.

Fetal parameters

Deciphering 2 screening during pregnancy is to analyze the data obtained during the ultrasound examination. In the second trimester, the fetus is actively growing, so there will be a big difference between the indicators of weeks 16 and 20. It should also be understood that all babies develop individually. If the doctor said that any parameter is normal, then it is so.

One of the most important indicators is the height and weight of the baby. If at the beginning of the 2nd trimester the fetus weighs only 100 g, then by its end this figure is already 300 g. The growth of the baby also changes, at first it is 11.6 cm, and by the 20th week the child grows in length to 16.4 cm. during the ultrasound examination, the doctor necessarily measures the circumference of the head and tummy. The first indicator at week 16 is from 112 to 136 mm. By the end of the trimester, the head circumference should be between 154 and 186 mm. The second indicator should have values from 88 to 164 mm.

Then the doctor finds out the fronto-occipital size. At the beginning of the trimester, it should be in the range from 41 to 49 mm, and at the end - from 59 to 68 mm. Another important parameter is the biparietal size. Normally, he31 to 53 mm (depending on the gestational age).

After the doctor measures the length of the leg bone. At the beginning of the trimester, this parameter should be from 15 to 21 mm, and at the end - from 26 to 34 mm. The length of the baby's femur is also measured. It should be from 17 to 37 mm (depending on the week of the study). What does 2 screening during pregnancy show? It gives an idea of how the baby is developing.

The doctor must measure the humerus of the fetus, normally it should be from 15 to 34 mm. This value is directly related to the gestational age. The older the baby, the higher this figure. Then the doctor pays attention to the length of the bones of the forearm, this indicator should be in the range from 12 to 29 mm. The doctor also finds out the approximate volume of amniotic fluid. After that, he writes a conclusion.

Internal organs of the fetus

By the time of the scheduled ultrasound examination, the baby is already quite formed. Deciphering 2 screening during pregnancy includes an assessment of the work of its internal organs. Particular attention is paid to the heart. The doctor evaluates the rhythm and frequency of his contractions. In the second trimester, the heart occupies about a third of the fetal chest. The frequency of his beats is normally from 140 to 160 per minute. The doctor pays attention to the size of the heart, its location and the shape of the interventricular septum. The structure of the tissues of the myocardium, endocardium, and pericardium is also assessed.

By the time of screening, the child's respiratory system is already fully formed. The development of the lungs during ultrasound is assessed by the ratio of their echogenicity to the same indicator of the liver. The doctor determines the degree of maturity of the organ and its location. Normally, the lungs occupy about a third of the cross section of the chest.

By the end of the 2nd trimester, the formation of the kidneys, which began as early as 3 weeks after conception, ends. Depending on the gestational age, their size can be from 16 to 34 mm. The fetus already has a functioning digestive system. The doctor must examine the entire gastrointestinal tract. Also, by the 20th week of pregnancy, the formation of the adrenal glands ends. Normally, their size at this time ranges from 9-10 mm.

Blood biochemistry

How is the 2nd pregnancy screening done? The doctor orders the woman to donate blood and undergo an ultrasound examination. Also at the appointment, the gynecologist talks about the time when you will need to reapply for an appointment. The doctor, focusing on the results of tests and the conclusions of specialists, prescribes treatment if necessary.

Usually, a specialist prescribes three types of blood tests, after which the level in the body of hCG, estriol, and a-fetoprotein will be known. Sometimes the expectant mother is advised to take another test that will show the content of inhibin A.

During the second trimester, the level of human chorionic gonadotropin ranges from 10 to 35 thousand units. On the 16th week, the blood should contain from 4.9 to 22.75 nmol / l of estriol, and on the 20th - already from 7.35 to 45.5 nanomoles perliter. The level of alpha-fetoprotein by the end of the trimester should not exceed 57 units.

The probability of deviations in the fetus will be calculated by the doctor by the multiplicity of the result of the marker to the average value. The optimal result will be equal to 1. The upper limit of this indicator will be 2.5, and the lower limit will be 0.5. Normally, the risk of fetal anomalies should not be less than 1 in 380.

False indicators

Expectant mothers often look forward to deciphering the 2nd pregnancy screening, but there may be errors in the conclusion. Naturally, this happens extremely rarely in the modern world, but there are precedents. Several error-producing factors can affect the results of decryption.

For example, false readings may appear in the conclusion of multiple pregnancies. Sometimes the cause of the error lies in the incorrectly set term of conception, since the baby may turn out to be a little younger or a little older than the doctors think. The exact gestational age is generally very difficult to determine, of course, if a woman has not become pregnant after IVF.

False indicators are also possible if the expectant mother is obese or diabetic. At risk for misinterpretation of the results are women aged 35 and older. Another reason for errors in screening is the bad habits of the expectant mother: drug addiction, substance abuse, smoking, alcoholism. Incorrect results can be obtained by women who took hormonal drugs or underwent in vitro fertilization.

Possible deviations

What is determined at the 2nd screening during pregnancy? The doctor looks at how the baby develops. Sometimes, according to the results of the tests, some pathologies can be suspected in the fetus. For example, with low estriol, experts suggest intrauterine infection of the embryo. On the same basis, adrenal hypoplasia, anencephaly, fetoplacental insufficiency can be suspected. In some cases, this indicator also suggests Down syndrome in a baby. With low estriol, there is a high risk of premature birth. If the indicator is increased, then this can indicate both multiple pregnancies and liver disease in the expectant mother.

Low AFP is often a symptom of Edwards syndrome. In some cases, a similar result of the analysis indicates intrauterine fetal death. Also, a low level of this substance can be a symptom of Down syndrome. A high level of alpha-fetoprotein indicates the following diseases: Meckel syndrome, umbilical hernia, malformation of the nervous system, liver cell death.

Low hCG values in some cases indicate the development of Edwards syndrome in the fetus. A high level of human chorionic gonadotropin indicates that the baby has Down syndrome or Klinefelter syndrome. However, sometimes such a symptom only indicates that the pregnancy occurred as a result of IVF.

Next steps

Reviews about 2 pregnancy screenings are mostly positive, as it often shows that the baby is he althy. Women understand thatstudies are necessary, therefore, they follow the prescriptions of doctors meekly. In the reviews, they write that it is quite simple to pass tests. A little discomfort associated with visiting the clinic does not scare anyone, because the most important thing is to know that the pregnancy is developing normally.

But what to do if the results of the decryption are not pleasing? In this case, you can not give up. Sometimes a follow-up ultrasound scan after a few weeks is enough to make sure everything is fine with the baby.

Your doctor may also recommend an amniocentesis. In this procedure, the doctor removes a small amount of amniotic fluid through a puncture in the peritoneum. Usually the result of the analysis shows that the baby is he althy. The downside of this study is that it can sometimes induce miscarriage.