Blood pregnancy tests examine the exact value of beta- HCG concentration in serum and with high probability can determine the presence or absence of pregnancy. Many couples trying to have a baby do not know when the earliest this test should be performed to give a reliable result. What beta HCG levels are indicative of pregnancy? In which week to perform the test?
Blood pregnancy test- how does it work?
Available pregnancy tests detect the beta subunit of chorionic gonadotropin (beta-HCG). It is a hormone produced by the cells of the syncytiotrophoblast (a component of the later placenta). Beta- HCG is contained in both a woman’s urine and blood. However, it first appears in the blood, so this test is able to detect pregnancy earlier.
A positive blood pregnancy test, however, does not equate to a diagnosis of pregnancy, as beta- HCG levels are also increased in ectopic pregnancies and in the case of mycetoma, among others. For this reason, any result should be interpreted by a specialist and supplemented by an ultrasound examination.
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Blood pregnancy test- preparation
To take a blood pregnancy test, it is best to go to an area clinic. The nurse will draw venous blood into a tube and transfer the material to the laboratory. There is no need for a woman to specially prepare for this test. Importantly, you don’t have to be fasting either. A referral from a doctor is also not necessary.
Blood pregnancy test-when is the earliest?
Pregnancy tests that detect the presence of beta- HCG in urine can be performed at the earliest on the date of expected menstruation. It is then, after implantation, that the concentration of this hormone begins to rise rapidly. Blood pregnancy tests, on the other hand, can be performed as early as about 8- 10 days after conception.
However, it should be borne in mind that in order to be sure whether the pregnancy is normal and the implantation has occurred in the uterine cavity, a woman should see a gynecologist. He, during the ultrasound examination, is able to locate the embryo and its beating heart. It is believed that, when the concentration of beta- HCG in the blood is 1200 mlU/ml, the pregnancy follicle should be visible in the uterine cavity. In turn, the baby’s heart activity is usually visible when the concentration of chorionic gonadotropin reaches about 10 thousand mlU/ml.
Blood pregnancy test- result
The production of chorionic gonadotropin increases sharply after the embryo is implanted. In the first weeks of pregnancy, it doubles in value every 48 hours or so. Based on this, the early gestational age can be estimated. However, this is not a precise measurement and should not be used to estimate the date of delivery.
The highest concentration of beta- HCG is between 9. a 12. week of pregnancy. It is believed that when the beta- HCG result is below 10mlU/ml the presence of pregnancy can be ruled out. And when it exceeds 25 mlU/ml with high probability a woman is pregnant. It is worth knowing that this result is higher for multiple pregnancies.
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