What does a double test for β-hCG and PAPP show during pregnancy?

Free hCG beta subunit is an indicator used in the study of a pregnant woman to determine the risk of Down syndrome in the fetus. It is much more informative than general hCG. This is a test prescribed to a woman in the 1st trimester of pregnancy, which will protect her body from dangerous pathology. The expectant mother is tested from 9 to 13 weeks.

What is a double test

Today there are 2 main types:

• double test;
• triple test.

They are aimed at identifying congenital defects and developmental anomalies in the unborn child, but are done at different times.

Double - test, double test, perinatal screening during pregnancy - these various names are often scary and raise only one question: “What is this?”

In reality, behind this list of varied and complex terms, the same procedure is hidden. It includes an ultrasound examination of the condition of the fetus and amniotic membranes, and a biochemical blood test.

A mother's blood test can help determine the risk of certain genetic diseases.

Beta hCG was elevated at 1st screening

Who had this happen? PAPP is normal, and hCG is normal up to 130, I have 179. According to the ultrasound, everything is fine, but they haven’t sent me risk calculations yet, so I’m a little worried. I take a lot of utrozhestan - maybe because of it it may be elevated.

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definitely ask your doctor

Yes, after lunch I will receive a risk calculation, but in the meantime I was thinking, maybe someone else has had this happen, find out.

Yes, the fact is that these tests will not say that everything is 100% fine with the child or vice versa. Based on the results of the analysis, you can only find out how high the risk of these abnormalities is in a child. According to ultrasound, my risk is approximately 1:30,000. And the blood test will obviously be higher, since the result is higher than normal, but I’m worried about HOW much higher it will be.

Oh, I was just in 3D. As the doctor explained to me, they only take photos in 3D, but they still look at them in 2D, because this way you can see all the dimensions and contours more clearly.

discussing this now is like a finger in the sky

The main thing is that everything is fine according to the ultrasound, and if they don’t like something, then in conclusion they write a consultation with a hepatic specialist.

Honestly, I don’t know, they didn’t say anything, I took it, they said it was normal and that’s all, but for some reason I took it to the lcd at 16 weeks... And the ultrasound was at 12... Don’t push yourself ahead of time, everything will be fine, maybe because support, it may be an error. 2 different labs gave me 2 different rhesus at one time %) From my own experience I will say that the less you stress yourself out during B, the better it goes, of course you can’t leave everything to the doctors, trust, but check, but don’t bother at all costs.

Enjoy this time. It will fly by quickly)

Apparently, only a water analysis can give an accurate result... which geneticists prescribe in such cases - they actually count the number of chromosomes.

No, well, in my case this test will not be prescribed; it is prescribed if the thickness of the cervical fold on the ultrasound does not correspond to the norm. And everything is fine with me there.

To be honest, I have no idea, I don’t even know if they took my blood for hCG, the main thing is that everything is fine according to the ultrasound

We suggest you read: What does the mucus plug look like and how does it come off before childbirth?

But in general, what could be so terrible about an elevated hCG.

Chromosomal abnormalities, such as Down syndrome

mm... And in general, this is what I think about these anomalies. Doctors often make mistakes. There are many such vivid stories on the Internet where doctors made terrible diagnoses, but the mother did not listen to them and gave birth to a healthy child. In the gynecology department there are always girls whom the doctors told that the child would have some kind of developmental disorder and they performed an artificial abortion, and the period is no longer short - 20 weeks, when you already feel the child... I saw these girls, you wouldn’t wish this on your enemy. They walked like zombies because... they were on strong medications and because of them everything was no longer important to them.

So, all these screenings are done in order to have an abortion “on time”. But will you really have an abortion if they tell you that the risk of developing Down syndrome is, for example, 1/10? or 1/100? Some do. But I would never do it. Therefore, I don’t even see the point in identifying these risks. The main thing is that the baby grows and develops in a timely manner that is good and comfortable for him. The main thing is not to poison him intentionally or accidentally. I think so.

When to do it

Biochemical screening takes place at 11-13 weeks. At this stage, a woman’s blood contains 2 important indicators:

• β-hCG;
• PAPP-A.

Substances are called markers of possible pathologies of child development.

If this study is carried out earlier or later than the specified period, it will be uninformative and will show erroneous results.

Screening is mandatory for all women, but special attention should be paid to:

• women over 35 years of age;
• pregnant women who have already given birth to children with pathologies;
• patients with family history of genetic and chromosomal diseases.

When does hCG begin to be produced during pregnancy?

The hormone is formed 6-8 days after the fusion of the egg and sperm. The maximum concentration is found in the period from 7 to 11 weeks. After this, its value begins to decrease. Therefore, a high level of the laboratory indicator in question in the biomaterial at an early stage is a normal physiological phenomenon.

However, increased levels of human chorionic gonadotropin after the end of the second trimester may indicate chromosomal mutations in the developing fetus. For men and women who are not carrying a child, the test must be negative or a minimum value (no more than 5 mU/ml for women and less than 2.5 for men).

What does the analysis determine?

Studies conducted during biochemical screening are aimed at determining the likelihood of developing chromosomal pathologies in the fetus.
At the end of the first trimester of pregnancy, you can already find out the risk of such diseases as:

• Down syndrome;
• Anencephaly;
• Edwards syndrome;
• Spinal canal cleft.

Down syndrome or trisomy 21 pairs of chromosomes is a fairly common disease in the modern world. Thus, we get not two, but three chromosomes.

Children with this diagnosis have a characteristic appearance. With broad features, slanted eyes and a fairly short nose.

The disease is accompanied by mental retardation, cerebral palsy and other multiple pathologies of the development of internal organs.

Anencephaly or absence of a brain. This pathology can be determined by ultrasound. Such children are not viable.

As in the case of Down syndrome, an extra chromosome appears in the 18th pair.

This disease is accompanied by a large number of concomitant pathologies. Unfortunately, these babies usually do not survive birth.

Spinal bifida, or spina bifida, is a neural tube disorder that affects the spinal cord.

After birth, babies will not be able to fully move and will most likely be paralyzed.

If this pathology has accompanying deviations of internal organs, then the child is not viable.

How to check the level

After fertilization, the embryo produces a hormone - human chorionic gonadotropin. The well-being of the pregnant woman, the condition of the child, and the prevention of complications depend on it. The study helps identify patients at risk of developing complications during pregnancy.

Free beta hCG is a marker: its deviation from the norm indicates the likelihood of having a child with a chromosomal pathology. The amount of the hormone is determined using ELISA analysis. Beta-hCG is a glycoprotein, weighs 40 kDa, consists of 2 units - alpha and beta. The free beta subunit has a special specificity.

The hormone is formed 9 days after the LH peak, 24 hours after the fertilized egg attaches to the uterine wall. Free hCG is detected in the blood on the 6th day after fertilization.

On day 8, the beta subunit increases and doubles every 2 days. After the 10th week of pregnancy, the amount of gonadotropin in the blood decreases and amounts to 5000-50000 IU/l.

The beta unit of gonadotropin remains in the blood for 40 weeks, the ratio of alpha and beta particles is determined according to the proportion of 12:1.

If a chromosomal pathology occurs in the 1st trimester, b-gonadotropin increases much faster than the amount of hCG, so the free hormone is used for prenatal testing.

Important information: On what day of the cycle should women take FSH and LH?

In the 2nd trimester, the determination of total hormonal gonadotropin and b-subunit is used. In the case of trisomy 21, the amount of gonadotropin subunit increases in the 1st trimester and amounts to 2 MoM. The amount of chorionic hormone is prognostic for the entire period of pregnancy. If it is below 10, fetal growth retardation develops in 45% of cases, and miscarriage occurs in 27.3%.

Protein standards in the first trimester

To determine the likelihood of a particular syndrome occurring, the content of proteins in the blood such as:

• PAPP-A (pregnancy-associated plasma protein A);
• β-hCG (beta subunit of human chorionic gonadotropin).

Table of normal values ​​for PAPP-A (mU/ml) and β-hCG (ng/ml)

PAPP-A - what is this protein and what role does it play?

By its chemical nature, this protein is a glycoprotein.
Trophoblast plays an important role in its synthesis. During pregnancy, PAPP-A is produced in the woman's body throughout the entire period.

The level of PAPP-A content corresponds to the duration of pregnancy and increases as it increases.

β-hCG - what kind of protein is it and what role does it play?

This protein also belongs to the group of glycoproteins and plays an important role in maintaining pregnancy in the initial stages.

It supports the work of the corpus luteum at the embryonic stage of fetal development.

As pregnancy progresses, hCG drops.

The norm of the beta subunit of human chorionic gonadotropin and deviations from it

Human chorionic gonadotropin (hCG) is a hormone produced by the cells of the fetal membrane of the embryo. This is the main laboratory marker of the development of pregnancy, the quality of its course and the presence of any deviations in the process of bearing a baby.

Free hCG is the fraction of this biologically active substance not bound to proteins. It is this that can be detected using special laboratory tests. The sum of free and bound biological substances makes up the total hCG level in the body. Normally, it appears only during pregnancy, which must be taken into account when interpreting the results of specific tests.

What do changes in protein levels indicate?

Deviations both upward and downward from the norm in hCG and PAPP-A levels indicate a risk of developmental abnormalities in the child.
A decrease in the amount of PAPP-A in a woman’s blood, together with an increase in hCG levels, signals a risk of Down syndrome.

Elevated hCG levels can occur in the presence of diabetes, multiple pregnancy, or severe toxicosis.

A low level may also indicate existing problems.

A decrease in the concentration of this protein is observed when:

• ectopic pregnancy;
• development of Edwards syndrome;
• threat of premature termination of pregnancy;
• placental insufficiency.

The reliability of deciphering the results of this test does not exceed 70%. Therefore, in addition to a blood test, it is necessary to undergo an ultrasound examination. It will help determine the diagnosis more accurately.

There are variants of false negative results. In this case, most likely, the diseases will be detected at the 2nd perinatal screening at 18-20 weeks.

Deviations in test results

If it was previously said that hCG is the main marker of pregnancy, then it is also worth knowing that its concentration can suggest the presence of a number of pathologies.

If the amount of hCG is below normal, then doctors suspect:

• Incorrect attachment of the fruit egg. Ectopic pregnancy is a relatively common pathology that requires surgical intervention to prevent a threat to the mother’s life.
• Intrauterine growth retardation. A lack of hCG leads to an insufficient amount of progesterone in a woman’s blood. This, in turn, causes insufficiently active growth of all organs and systems of the embryo, which causes a delay in its development.
• Threatened miscarriage.
• A pregnancy that does not develop.
• Placental insufficiency. With a lack of functional activity of this organ, a progressive decrease in the amount of hCG in a woman’s blood is observed.

All these situations require appropriate intervention from doctors to ensure the quality development of the fetus.

However, there are a number of individual situations in which there is a sharp increase in the amount of hCG in the blood of a pregnant woman. A similar situation can occur when:

• Progression of multiple pregnancy.
• Toxicosis of various origins.
• Development or progression of diabetes mellitus.
• The presence of fetal malformations.
• Concurrent use of medications that contain hCG.

In any case, it is necessary to correct the underlying disease or cause that caused the jump in hCG

It is also very important to remember that just because of a rise or fall in the concentration of a hormone in the blood, no doctor will hastily make a particular diagnosis. This situation is evidence of the presence of a certain pathology or not entirely physiological condition, and requires additional examination in order to establish the cause of this phenomenon.

How to test for -hCG and PAPP

To get the most reliable results of a biochemical blood screening, you need to properly prepare for it.
The preparatory activities are extremely simple. The day before, you should refrain from eating fatty, smoked or too salty foods. Try to minimize the use of spices.

The analysis is given on an empty stomach. Therefore, it would be wise to take food with you so that you can have a snack immediately after donating blood.

Blood for analysis is taken from a vein.

The referral for this study is given by an obstetrician-gynecologist. The results are also reported by the local doctor.

It is very important not to miss the required deadline for carrying out this analysis. Otherwise, you may get unreliable results.

High hCG: what to do

An elevated level of hCG during pregnancy is a reason to be wary, but not a reason to panic. Determining what leads to excessive production of the hormone is the doctor’s task. A pregnant woman needs to undergo tests in a timely manner and listen to the doctor’s recommendations. If the hormone concentration is elevated, you cannot refuse additional tests prescribed by your doctor. Only comprehensive diagnostics will help identify the problem and solve it.

Some conditions characterized by elevated hCG do not require medical intervention. These include toxicosis and multiple births. The only measure the doctor takes is to develop an individual pregnancy management plan. Multiple pregnancy and toxicosis require careful monitoring of the mother’s health and the condition of the embryo/s throughout the gestation period.

If excessive hormone levels indicate a genetic pathology of the fetus, then the only thing parents can do is make the right decision. However, this must be preceded by a thorough diagnosis, eliminating the possibility of an erroneous diagnosis. If chromosomal abnormalities are suspected, screening is recommended to be carried out in several laboratories, contacting not only a qualified gynecologist, but also a professional geneticist. The opinions of several genetic disease specialists may be needed.

When the concentration of the hormone is caused by serious problems with women's health, it is important to quickly take measures that will help preserve reproductive function. If this is possible, then timely therapy allows you to maintain the pregnancy. You need to trust your doctor and follow the treatment plan he has developed.

What to do with the results

Testing a pregnant woman’s blood for the risk of developing pathologies takes about 10 days.

Results are usually reported after 2 weeks.

Results are usually written in MoM units.

This is not a number that shows the quantitative protein content, but an indicator of deviation from the norm.

The normal MoM value is from 0.5 to 2.

If the test shows results above the acceptable cut-off threshold, this means that the likelihood of developmental abnormalities in the child is quite high.

If the study shows a result below the cutoff threshold, this indicates the likelihood of a miscarriage or the development of Edwards syndrome in the child.

If the results are negative, the woman is offered to undergo additional studies:

• amniocentesis - examination of amniotic fluid;
• cordocentesis - umbilical cord blood analysis;
• genetic consultation;
• additional ultrasound examination.

These tests, in turn, will give a more accurate answer about the possibility of having a sick child.

If the diagnosis is confirmed by other studies, the pregnant woman may be offered surgery to terminate it.

The decision and choice remains solely with the woman. This event is not held forcibly.

A woman has the right to refuse screening tests in writing.

1 screening during pregnancy is a very important procedure that allows you to answer many questions. Currently, this procedure is included in the list of mandatory for pregnant women.

Author: Anita Igorevna, pediatrician Specially for the site kakrodit.ru

What is the hormone for?

Total and free hCG performs a number of important functions in a woman’s body during pregnancy. As mentioned above, it can appear in the blood only after the embryo attaches to the endometrium of the uterus. The appearance of this substance in the body when the woman’s body is not pregnant indicates:

• The presence of a hormonally active tumor or hydatidiform mole.
• Carrying out an abortion.
• Taking medications containing human chorionic gonadotropin.

Despite these features, you need to understand that hCG plays a vital role in the process of bearing a child by the mother’s body. It is produced by the cells of the outer membrane of the embryo. At the blastula and morula stages, two layers of cells are conventionally distinguished - embryoblast and trophoblast. If all the organs and systems of the future baby develop from the first, then the chorion and future placenta are formed from the second. It is these cells that are responsible for the connection between the child and the mother’s body and affect both her and the developing body.

The main functions performed by free beta hCG during pregnancy are:

• Activation of the corpus luteum. Normally, it goes through a stage of physiological involution every month in 12-14 days after ovulation. However, when the egg is fertilized by a sperm, and the embryo attaches to the endometrium and begins to produce hCG, it continues its work. Its main task remains the synthesis of large doses of progesterone to ensure the gradual progression of pregnancy. This hormone guarantees the normal process of fixation of the unborn child in the wall of the uterus with its subsequent adequate development.
• Stimulation of the synthesis of estrogens and androgens by ovarian cells. This helps to increase the activity of chorionic villi and the future placenta, which ensures the normal process of fetal trophism.
• When the placenta has already formed, and the corpus luteum can safely function without the influence of hCG, its role is reduced to activating the synthesis of testosterone and other sex hormones, but in the embryo’s body. Thanks to this activity, the baby’s reproductive system develops smoothly.

As you can see, free hCG during pregnancy functions as the main regulator of the process of bearing a baby. By its concentration in the blood one can judge the quality of pregnancy and the presence of certain abnormalities. As for the free B subunit of hCG, it remains a unique component of the hormone, which is responsible for its specific effect on the corresponding structures in the woman’s body and the possibility of conducting specialized tests for its detection in biological materials.

Versus 1: Ultrasound harms baby

There is a fairly widespread opinion that ultrasound negatively affects the child’s nervous system and irritates him - during the examination, children often try to hide from the machine and cover their heads with their hands. Therefore, children whose mothers regularly had ultrasound scans during pregnancy are more restless compared to babies whose mothers refused ultrasound diagnostics. Is it really?

According to doctors, ultrasound cannot cause any harm to the baby - modern equipment is absolutely safe. Therefore, official medicine insists that absolutely all pregnant women undergo an ultrasound. After all, timely diagnosis allows, firstly, to see the full picture of the course of pregnancy, and secondly, if necessary, to correct certain problems.

An ultrasound examination is performed at least three times during pregnancy (in the first trimester at 11-13 weeks, in the second at 18-21 and in the third at 30-32 weeks), but if necessary, the doctor may recommend it be done more often.

The data obtained from the ultrasound of the first prenatal screening (at 11-13 weeks of pregnancy) are considered especially important. At this time during the study:

• the number of embryos in the uterus and their viability are determined;
• a more accurate gestational age is set;
• gross malformations are excluded;
• the thickness of the collar space is determined - TVP (i.e. the amount of subcutaneous fluid on the back surface of the child’s neck is measured - normally TVP should not exceed 2.7 mm);
• The presence or absence of the nasal bone is examined.

For example, in children with Down syndrome, the fluid content is much higher than normal, and the nasal bone is often not visualized.

HCG in non-pregnant women

There are cases where the free beta subunit of hCG is elevated in the absence of pregnancy or even in a man. This is not always the norm. The reference values, regardless of gender, are considered normal: 0-2 ng/ml.

The appearance and increase of this substance in the blood plasma in the absence of pregnancy above the specified value will indicate:

• hydatidiform mole or hormone-dependent tumor in a woman;
• an abortion performed about 5 days ago;
• taking gestagens;
• recurrence of cancer after irradiation;
• testicular tumors in men;
• neoplasms in the intestines;
• cancer of the kidneys and lungs;
• malignant tumors in the uterus.

In the case of malignant tumors, the level of the hormone free beta subunit of hCG above normal in the blood can be used as a tumor marker when there will be no clinical symptoms in the next few months. With successful surgical intervention in such patients, the hormone level returns to normal within 2-3 days. Otherwise, the numbers indicate damage to other organs and systems or poor quality treatment.

Reasons for low hCG levels in expectant mothers

The transition of hCG beyond the normal line towards a decrease during gestation also requires serious attention, since it indicates a pathology of pregnancy or a chronic disease in the woman herself.

Such reasons include:

• ectopic pregnancy;
• frozen gestation or death of the fetus in the womb;
• chronic hormone deficiency in the placenta;
• post-term pregnancy; threat of miscarriage (in this case, hCG drops by 2 times at once).

All possible pathologies should be checked as soon as possible to avoid complications.

If the rate of free beta subunit of hCG is lower than the expected rate, most likely carrying a further pregnancy will be impossible or risky. If hCG is low during late prenatal screening in a pregnant woman, one may suspect delayed growth or development of the future baby.

Final 3rd trimester

Here, hormone levels are measured very rarely, because it is impractical. But generally accepted norms exist here too. And the reader has the opportunity to familiarize himself with them.

From the 23rd to the 40th week it should not be higher than 2700-78100 IU/ml. Inflated rates are typical for multiple pregnancies. Specifically, the 40th week of pregnancy has indicators of 60,000-70,000 units - this is the norm for the free beta subunit of hCG in this case.

If there are deviations from these figures, the doctor may suspect the following disorders of the current pregnancy:

• possibility of miscarriage;
• frozen pregnancy;
• ectopic pregnancy;
• hormone deficiency in the placenta.

Norm and units of measurement

The rate of free beta subunit of hCG in the blood throughout the entire gestation period is expressed in the following units:

• honey/ml (milli-units);
• mIU/ml (milli-international units);
• 1 mU/ml = 1 mmU/ml.

Sometimes the laboratory gives results in international units, which are generally similar to those named, ng/ml (nanograms per milliliter), etc. The rate of free beta subunit of hCG in laboratories of medical institutions may vary. The discrepancy is explained by different methods and equipment. The optimal solution would be to take tests in one laboratory. Tracking the dynamics of hCG changes in the blood will become more reliable.

Sometimes honey/l occurs. To obtain the norm of the free beta subunit of hCG in mU/l, 1 ng/ml x 21.28 = 1 mU/l.

Transition to 2nd trimester

So, second trimester. At this stage, the level of free beta subunit of hCG during pregnancy begins to decline. But with twins, it may remain the same or even increase slightly, which doctors consider normal.

The rate of free beta subunit of hCG from 13 to 18 weeks will be from 6140 to 103,000 units. Subsequently, until week 24, the hCG level is 80 thousand IU/ml.