A blood test for pregnancy in the early stages will give all comprehensive information about how many children (one or more in the uterus), and what is the health of the fetus.
When pregnancy occurs, a blood test must be performed to protect the woman and her fetus from possible complications. This may be a frozen pregnancy or hormonal failure. But the most dangerous complication, of course, is an ectopic pregnancy, which must be detected as soon as possible.
A general blood test is also required by doctors to take. Data on a woman’s health is needed to predict how difficult a birth will be.
Blood test for pregnancy
If a woman does not yet know about her pregnancy and is just starting to worry about what caused the delay, you need to immediately go to the clinic and donate blood for analysis, rather than wasting time on tests. After all, tests can still give an error. It is better to do an analysis and find out what is the level of the hCG hormone.
A blood test for hCG during pregnancy gives an accurate prognosis as early as 9-10 days after conception. But it is better to take the analysis after 4 weeks, and then repeat somewhere around 10 weeks. The test can give a positive result much later. The maximum level of hCG is usually between 10-11 weeks of gestation and continues to rise.
What is the hCG hormone?
The hCG hormone or human chorionic gonadotropin produces chorion tissue one day after zygote implantation. Its presence in the blood indicates pregnancy. However, not only for pregnancy. The hormone also rises gradually when a tumor appears in the body.
In the very first weeks of pregnancy, the level of the hormone can answer the question of the date of conception and the estimated date of birth.
A blood test for pregnancy is usually performed once or twice at the beginning of the first trimester to clarify the pregnancy. Then it is not needed if there is no indication for constant monitoring. The level is compared with the norms, and a woman, when everything is fine, can no longer worry. If hCG in the first trimester is normal, then the planned pregnancy has taken place and the embryo is developing safely in the uterus.
The standards are as follows:
- 4 weeks: 5-426 mU / ml (mIU / ml);
- 7-8 weeks: 7.650-229,000 ppm / ml (mIU / ml);
- 16 weeks: 13,300-254,000 ppm / ml (mIU / ml).
These indicators may vary somewhat, but not too much. Very low rates, as well as too high, indicate abnormalities in the development of the fetus.
Analysis for the hCG hormone is mandatory after IVF. In these cases, it is important to immediately determine whether the embryos have taken root, and how many of them. An analysis is made without fail for those women who cannot become pregnant due to amenorrhea.
In men, blood is also sometimes checked for hCG hormone when there is suspicion of genital cancer.
How to donate blood for hCG
Blood for analysis is given only on an empty stomach. Before going to the clinic, you can’t eat for about 6 hours. If there is sugar in the blood, the test will be incorrect. It is best to come for analysis in the morning, on an empty stomach. Moreover, 24 hours before blood donation there is nothing fatty - only lean foods.
One more thing needs to be mentioned - before donating blood, a woman should not physically strain. It is also impossible to undergo physiotherapeutic procedures before this.
If a woman is taking any medications, a doctor should be warned about this.
You can re-take a blood test for pregnancy after 3-4 days for more reliable results.
What does low hCG mean during pregnancy?
Low rates indicate a fading pregnancy or miscarriage. If a woman has problems with bearing, and previously had miscarriages, this analysis can be done in the second and third semester.
Also, with an ectopic pregnancy, the hCG rate will be low. Such a pregnancy is life-threatening for a woman, and doctors immediately put on an operation to remove the fetus until the fallopian tube ruptures.
Hormone too high
A blood test that determines pregnancy sometimes gives indicators that are too high for 1 month. Such data often signal a multiple pregnancy. With gestosis or the presence of diabetes in the mother, the level is also slightly higher.
Another factor is the threat of the development of genetic pathologies in the fetus, for example, Down syndrome. However, the level can also sometimes be overestimated if a woman takes synthetic progestogens. What is gestagen? This is a hormone that helps to take root in an embryo in the uterus. For women, the hormone is very important, but usually it is produced in the body in the right amount if there is no hormonal malfunction.
Functions of Chorionic Gonadropin
Why is hCG hormone needed in the body of a pregnant woman? HCG activates the corpus luteum in women. Without his participation, the birth of life is impossible.
In addition, human chorionic gonadropin performs the following functions:
- Increases progesterone production.
- Prepares maternal immunity for gestation.
- If the embryo is a boy genetically, hCG starts the production of personal testosterone in the fetus so that it already develops male signs.
In non-pregnant women, elevated hormone levels may indicate ovarian tumors due to hormonal imbalance.
Types of HCG
There are 2 subunits of the chorionic hormone. The alpha subunit and beta are gonadotropin.
HCG in its biological structure is a glycoprotein. The alpha subunit is more similar in properties to thyroid-stimulating hormone or luteinizing. But he is not involved in bearing a child. It is beta-hCG that determines the presence of pregnancy. A blood test shows pregnancy when the level of hCG in the blood is already quite large. A confirming factor will be the presence of a fetal heartbeat at the first ultrasound. The level of beta subunits doubles every 48-72 hours in the first month.
The level rises to 16 weeks, and then stays at approximately the same level until the preparatory stage for labor is started in the mother's body. This occurs at week 34-35, and then the hormone, for some reason that has not yet been studied, is again actively produced.
Early Analysis
Doctors take a complete blood count during pregnancy to see if there is a risk to the fetus. When a pregnant woman has any kind of virus or a lack of red blood cells.
What other indicators look in the general analysis of blood? Be sure to look at the level of ESR, hemoglobin and white blood cells. The erythrocyte sedimentation rate indicates inflammation in the woman’s body. Which organ is inflamed, further studies will show.
Abnormalities in the general analysis of blood
The most dangerous for a woman during the gestation period is to become infected with the virus. Viruses such as toxoplasmosis, herpes and others lead in most cases to fetal death. Even a small virus attack can be detected precisely by the level of leukocytes in the blood. If the number of leukocytes in plasma is increased, then there is some kind of struggle in the body, and white blood cells need help with drug therapy.
Another important indicator in a general blood test is hemoglobin. This is a protein that carries iron ion and oxygen. And when there is little hemoglobin, the blood poorly performs the function of transporting oxygen. The lack of this leads to general weakness, dizziness and possible fainting.
In the body of a pregnant woman, blood plasma norms increase by an average of 35-50%. And the number of red blood cells is only 25%.
We can trace the dynamics of these changes in blood tests during pregnancy. The norms of red blood cells are as follows:
Term pregnancy | Norms of red blood cells / million per 1 μl |
| 1 trimester | 4.2-5.4 |
| 2 trimester | 3.5-4.8 |
| 3 trimester | 3.7-5 |
Not pregnant women | 4.2-5.4 |
However, when a woman has severe toxicosis in the first trimester, the number of red blood cells, on the contrary, increases faster than the substance of the plasma. And this is a common reaction to dehydration, not an abnormality.
ESR rates for all are different during pregnancy. In some girls, the indicator rises, in others - on the contrary, decreases. The average rate for non-pregnant girls is considered to be from 2 to 15 mm / h, and in pregnant women the ESR does not usually exceed 45 mm / h. Although there may be higher rates.
The erythrocyte sedimentation rate depends on nutrition. Girls who eat more plant foods have low ESR. And those who eat mainly proteins of various origins will see high rates in the results of a blood test.
Analysis for hCG in the 3rd trimester
Usually in the last trimester, the level of hCG no longer needs to be measured. Its level is approximately known to doctors.
And, if there is no multiple pregnancy or cystic drift, there are no signs of pregnancy fading by ultrasound, doctors will no longer send for this analysis.
Pathology of the embryo and hCG
All abnormalities of the fetal development can be traced by observing the level of hCG in dynamics. When the concentration of chorionic gonadotropin in the blood is increased, there may be trisomy in the child’s genome, indicating Down syndrome. But if the level, on the contrary, is significantly reduced, then either Patau syndrome or Edwards can be suspected. Edwards syndrome is characterized by the fact that there is no dynamics, and the hormone has ceased to be secreted. But it can also mean a frozen pregnancy.
However, you can not judge solely by blood analysis. The diagnosis is also confirmed by ultrasound, and additional tests are carried out to confirm or refute the assumption.
In the blood of pregnant women, the content of estriol and alpha-fetoprotein is sometimes checked. These indicators determine the presence / absence of defects in the neural tube of the fetus or multiple pregnancy. For example, with multiple pregnancy, all 3 indicators: estriol, hCG and alpha-fetoprotein will be greatly increased.
conclusions
We know that human chorionic gonadotropin is needed so that the embryo can be implanted into the mother's body, so that it prepares for its difficult task. Indicators above or below the norm indicate that not everything is so successful. Or, the gestational age of the calculation is incorrect, and confusion has turned out.
As you can see, the normal blood counts of a pregnant woman are very different from those that are expected for non-pregnant women. Therefore, to decipher the indicators, you must consult a doctor, and you should not try to figure it out on your own. Extra experience is completely useless.