The best way to confirm a pregnancy is through a blood test, as it detects small amounts of the hCG hormone produced during pregnancy, with the result being positive when the hormone beta-hCG levels are greater than 5.0 mlU / ml.
The pregnancy blood test should be done when your period is late so that the results are more reliable, because any test done before may have a false negative result. No medical prescription or fasting is required before the exam and the result is given within a few hours after the blood has been collected.
What is hCG?
HCG stands for human chorionic gonadotrophin, which is a hormone produced only when the woman is pregnant or has a severe hormonal change that is caused by a disease. The beta hCG blood test is usually only done when pregnancy is suspected, because it is more easily confirmed with the presence of this hormone in the blood than in urine, which is used in over-the-counter pregnancy tests.
However, when the Beta hCG test result is undetectable or inconclusive and the woman has symptoms of pregnancy, the test should be repeated 3 days later.
If you think you are pregnant, but have not yet taken the hCG beta test, you can do our online test to know what your chances of actually being pregnant are:
Quantitative Beta hCG Table
The following table shows the amount of Beta hCG hormones present in each week of gestation:
|Gestational age||Amount of Beta hCG in the blood test|
|You are not pregnant - Negative result||Inferior to 5 mlU/ml|
|3 weeks of pregnancy||5 to 50 mlU/ml|
|4 weeks of pregnancy||5 to 426 mlU/ml|
|5 weeks of pregnancy||18 to 7.340 mlU/ml|
|6 weeks of pregnancy||1.080 to 56.500 mlU/ml|
|7 to 8 weeks of pregnancy|
7.650 to 229.000 mlU/ml
|9 to 12 weeks of pregnancy||25.700 to 288.000 mlU/ml|
|13 to 16 weeks of pregnancy||13.300 to 254.000 mlU/ml|
|17 to 24 weeks of pregnancy||4.060 to 165.500 mlU/ml|
|25 to 40 weeks of pregnancy||3.640 a 117.000 mlU/ml|
The blood test should be done if your period is late, because if it is done before, you may get a false negative result, that is, the woman may be pregnant, but this doesn’t show up in the results. The body probably didn’t produce hCG hormone levels with enough concentrations to be detected and so indicate pregnancy.
Difference between quantitative and qualitative beta hCG
As the name implies, the quantitative beta-hCG test indicates the amount of hormone present in the blood. This examination is done from a blood sample that is sent to the laboratory for analysis and, with the result, it is possible to identify the concentration of the hCG hormone in the blood as well as, depending on the concentration, indicate the week of pregnancy.
The qualitative hCG beta test is the over-the-counter pregnancy test that only indicates whether the woman is pregnant or not, the concentration of the hormone in the blood not being given, so a gynecologist usually asks for a blood test to confirm pregnancy.
How to know if your pregnant with twins
n twin pregnancies, the hormone levels are higher than those indicated for each week, but to confirm and know the number of twins, an ultrasonography should be done from the 6th week of pregnancy.
The woman may suspect that she is pregnant with twins when she knows approximately which week she became pregnant and checks the table above to confirm the corresponding amount of beta hCG. If the numbers don’t correspond, she is possibly pregnant with more than 1 baby, but this can only be confirmed with an ultrasound.
Other exam results
Beta hCG results may also indicate problems such as ectopic pregnancy, miscarriage or anembryonic pregnancy, which is when the embryo doesn’t develop.
These problems can usually be identified when the hormone levels are lower than expected for the gestational age, and it is necessary to see an obstetrician to assess the cause of the hormonal change.
What to do after you confirm pregnancy
After confirming the pregnancy with the blood test, it is important to make an appointment with an obstetrician to begin prenatal follow-up, taking the necessary tests to ensure a healthy pregnancy without complications such as pre-eclampsia or gestational diabetes.