Free beta subunit of hCG - a measure used in the study of pregnant women to determine the risk of Down's syndrome in the fetus. It is much more informative than the total hCG. It's such a study, to appoint women in 1 trimester of pregnancy, which will prevent her body from dangerous diseases. Expectant mother is tested from 9 to 13 a week.
How to check the level of
After fertilization, the embryo produces a hormone - human chorionic gonadotropin. On it depends the well-being of the pregnant woman, the child, the prevention of complications. The study helps to identify patients at risk of complications during pregnancy.
Free Beta HCG is a marker: its deviation from the norm indicates the likelihood of having a baby with a chromosomal abnormality. Number hormone determined using ELISA analysis. Beta-hCG refers to glycoproteins, weight - 40 kDa, consists of 2 units - alpha and beta. Free beta subunit has a particular specificity.
Hormone formed after 9 days after LH peak at 24 hours after ovum attachment to the uterine wall. Free hCG detected in blood on day 6 after fertilization.
On day 8, the beta-subunit increases and doubles every 2 days. After 10 weeks of pregnancy, the amount of blood is gonadotrophin decreases and 5000-50000 IU / l.
Gonadotropin beta-unit is in the blood for 40 weeks, the ratio of alpha and beta particles is determined according to the proportions of 12: 1.
If there is a chromosomal abnormality in 1 trimester, b-gonadotropin increases much faster than the amount of hCG, so the free hormone is used for the prenatal study.
In the 2nd trimester used determination of total hormone and gonadotropin b-subunit. In the case of trisomy 21, the amount of gonadotropin subunit increases trimester 1 and 2 is MoM. Number of chorionic hormone is a predictor for the entire period of pregnancy. If it is below 10, in 45% of cases developing fetal growth retardation, 27.3% miscarriage occurs.
Norm
Norma during pregnancy for the b-subunit gonadotropin is:
- 3 weeks - 23,6-193,1 ng / ml;
- 10 - 25,8-181,6 ng / ml;
- 11 - 17,4-130,4 ng / ml;
- 12 - 13,4-128,5 ng / ml;
- 13 - 14,2-114,7 ng / ml.
In the 1st trimester of a woman determined by the free beta subunit of hCG, the rate of pregnancy - 1,099. A single study of the blood does not have diagnostic value, you must observe the dynamics of pregnancy. The result of analysis in the range of from 5 to 25 IU / ml did not confirm pregnancy.
To determine the amount of the hormone at 12 weeks necessary to deliver biomaterial - blood from a vein. On the study should be prepared in advance, otherwise the free b-subunit of hCG is not installed correctly.
It should not be smoking in 30 minutes before the procedure. In nonpregnant women reference values of 0-2 ng / mL.
The outcome of research is influenced by the following factors:
- floor;
- variety of tumors;
- treatment with cytotoxic drugs.
b-hCG free may differ if the patient donated blood in different laboratories. The doctor compares the symptoms of the disease with the results of research and appoint additional laboratory tests. B-subunit in the blood of non-pregnant women and men indicates the development of a dangerous disease.
The free b-subunit is at normal value fulfills a plurality of functions different from gonadotropin free and participates in the formation of the placenta.
The maximum rate of the beta subunit occurs at 9 weeks of pregnancy.
Ranges number b-2 horiotropnogo hormone in trimester because increases the placenta is able to produce the hormone without the participation of human gonadotropin.
That could mean deviation from the norm
Free hCG during pregnancy may have a higher value in the following cases:
- multiple pregnancy;
- type 2 diabetes;
- chromosomal disease;
- malformations of the embryo development;
- tumors formed by receiving gonadotropin.
chorionic hormone level reduction occurs when:
- ectopic pregnancy;
- a frozen fruit;
- begun abortion;
- death of a child before birth;
- chromosomal abnormalities.
14 week is critical in determining the level of hCG.
Results of the study together with the US figures reveal the risk of having a baby with a chromosomal abnormality. If you change the free beta-hCG in the 2nd trimester, the developing diseases such as hydatidiform mole and choriocarcinoma.
The difference in the unbound form and the dimeric hormone is that biological activity has integral. By installing the free hCG and a common beta-subunit, the doctor can get ahead of the deviation from the normal range. In this case, more research is needed.
What to do with deviations
Deficiency of hCG pregnancy during the gestation requires immediate hospitalization of women for emergency treatment, t. To. The possible miscarriage. Ectopic pregnancy is a serious condition, the patient - is urgently needed surgical intervention.
If your doctor has found that the fetus stopped, the child can not always save. Low gonadotropin with prolonged pregnancy requires artificial induction of labor. Reduction of hCG is carried out with the help of special treatment.
If the doctor suggests the emergence of a chromosomal pathology to cure this disease is impossible. When growing embryo ectopic pregnancy can cause rupture of the fallopian tube, severe bleeding into the abdominal cavity. Delayed assistance will lead to death.
Correction of the pathological state is carried out in a hospital environment, patient doctor prescribes injections of human chorionic gonadotropin.
Contraindications to administration of the drug:
- thrombophlebitis;
- pituitary tumor;
- hypoplasia of the gonads.
Saving pregnancy is possible only when sufficient blood gormona.v.
