Quantitative beta hCG is a blood test carried out to confirm pregnancy, as it allows the detection of small amounts of the hCG hormone, which is only produced during pregnancy. The result of the blood test indicates that the woman is pregnant when the beta hormone hCG values are greater than 5.0 mlU/ml.
It is recommended that this test only be carried out 10 days after fertilization, or on the first day after a missed period, to ensure a more reliable result. The beta hCG test can also be performed before the delay, but in this case, there is a greater chance of a false-negative result.
There is no need for a medical prescription or fasting to perform the test and the result can be reported within a few hours after collecting the blood and sending it to the laboratory.
Quantitative beta hCG calculator
If you have already taken the beta hCG test, enter your value to find out if you may be pregnant and, if so, for how many weeks:
What is hCG?
hCG is the acronym that represents the hormone chorionic gonadotropin, which is only produced when a woman is pregnant or has some serious hormonal change, which is caused by some disease. Normally, the beta HCG blood test is only performed when pregnancy is suspected, as the presence of this hormone in the blood is more indicative of pregnancy than the presence of this hormone in the urine, which is detected using a pharmacy pregnancy test.
However, when the beta hCG test result is undetectable or inconclusive and the woman presents symptoms of pregnancy, the test must be repeated 3 days later. See what the 10 first symptoms of pregnancy are.
How to understand the result
The result of the beta hCG test varies depending on whether the woman is pregnant or not, and the weeks of gestation:
It is recommended that the test be carried out after at least 10 days of missed menstruation, to avoid false results. This is because after fertilization, which takes place in the fallopian tubes, the fertilized egg can take several days to reach the uterus. Therefore, beta hCG values can take up to 6 days after fertilization to begin to increase.
If the test is carried out earlier, it is possible that a false-negative result will be reported, that is, the woman may be pregnant but this will not be reported during the test, as it is likely that the body has not been able to produce the hCG hormone in sufficient concentrations to be detectable and indicative of pregnancy.
How to know if you are pregnant with twins
In cases of twin pregnancy, the hormone values are higher than those indicated for each week, but to confirm and know the number of twins, an ultrasound must be performed from the 6th week of pregnancy.
A woman can suspect that she is pregnant with twins when she can know approximately which week she became pregnant, and compare it with the table above to see the corresponding amount of beta hCG. If the numbers don’t match up, she is possibly pregnant with more than 1 baby, but this can only be confirmed through ultrasound.
See what blood test to take to find out the baby’s sex before the ultrasound.
Other exam results
Beta hCG results can also indicate problems such as ectopic pregnancy, miscarriage or anembryonic pregnancy, which is when the embryo fails to develop.
These problems can usually be identified when hormone levels are lower than expected for the gestational age of the pregnancy, making it necessary to consult an obstetrician to assess the cause of the hormonal change.
Difference between quantitative and qualitative beta hCG
As the name suggests, the quantitative beta hCG test indicates the amount of hormone present in the blood. This test is carried out by collecting a blood sample that is sent to the laboratory for analysis. Based on the test results, it is possible to identify the concentration of the hCG hormone in the blood and, depending on the concentration, indicate the week of pregnancy.
The qualitative beta hCG test is the pharmacy pregnancy test that only indicates whether the woman is pregnant or not, without informing the concentration of hormone in the blood and the gynecologist recommends that a blood test be carried out to confirm the pregnancy. Understand better what qualitative beta hCG is, when to do it and results.
What to do after confirming pregnancy
After confirming the pregnancy with the blood test, it is important to make an appointment with the obstetrician to begin prenatal care, carrying out the necessary tests to ensure a healthy pregnancy, without complications such as pre-eclampsia or gestational diabetes. Find out which are the most important tests to take during the first trimester of pregnancy.
Bibliography
- GABBE, Steve G. et al.. Obstetrics: normal and pathological pregnancy. 6.ed. Rio de Janeiro: Elsevier, 2015. 18.
- AMERICAN PREGNANCY ASSOCIATION. hCG (Human Chorionic Gonadotropin): The Pregnancy Hormone. Disponível em: <https://americanpregnancy.org/while-pregnant/hcg-levels/>. Acesso em 27 nov 2019
- LONGO, Dan L. et al. Harrison Internal Medicine. 18.ed. São Paulo: AMGH Editora, 2013. 3592.
