Beta hCG is used in pregnancy tests to confirm or rule out conception. However, thanks to its concentration, the development of the pregnancy is also monitored - especially in the first weeks. An abnormal beta hCG result can be associated with serious fetal defects. For this reason, it is extremely important to control it regularly. When should this hormone be tested? What are the standards for its level? The answers to these questions can be found right here.
What is beta hCG?
Beta hCG is the beta subunit of chorionic gonadotropin, a hormone produced during pregnancy by the cells of the syncytiotrophoblast (one of the components of the placenta). It facilitates the maintenance of pregnancy, and conditions its proper development in the first days after conception. This is because the main role of beta hCG is to stimulate the corpus luteum to produce progesterone. This continues until the hormone begins to be produced in adequate amounts by the developed placenta.
Beta hCG is present in both the blood and urine of a pregnant woman – this is used in commonly available pregnancy tests. Chorionic gonadotropin is produced as early as 2. Week of pregnancy, and reaches its highest concentration between 60. a 80. day of pregnancy.
Beta hCG in pregnancy – when to test?
Determination of the concentration of chorionic gonadotropin in the blood can be done about 8-10 days after conception, that is, even before the date of expected menstruation. On the other hand, a urine test should be done only on the day of expected menstruation – otherwise the result sometimes turns out to be a false negative.
Pregnancy test vs. hCG hormone
Most often, the first step is for the mother-to-be to check whether she is pregnant, using a test available at the pharmacy – you can purchase it without a prescription, and it is very simple to do. Each package contains detailed instructions, which should be carefully read. However, the procedure is usually as follows.
- Sample collection – most tests require the collection of a urine sample. This can be done by placing the urine in a clean container and then dipping the test tip into it, or transferring a few drops onto it with the included pipette. Some models were created to direct the urine stream directly to them.
- Time to wait for the result – after placing the sample on the tip of the test, wait a few minutes. The exact time is always given in the instructions. In this way, the test can detect the presence of the hCG hormone, which is produced during pregnancy.
- Reading and interpreting the result – the result of the test is usually presented in the form of lines or symbols on the test. These should always be clearly stated in the instructions. For example, one line may indicate a negative result (no pregnancy), and two lines may indicate a positive result, i.e. pregnancy.
Beta hCG in pregnancy vs. pregnancy test sensitivity
Most tests have a success rate of about 95%. Standards for sensitivity most often detect the concentration of beta hCG in urine when its level will be higher than 5 mIU/ml.
For more reliable results, it is recommended to perform the test in the morning, when the concentration of hCG hormone in the urine is highest. If the result is positive or you have doubts about it, it will be advisable to consult a doctor. This is because he can suggest further testing and research. Also remember that pregnancy is counted from the first day of your last period. It is about 6 weeks after this date that the gynecologist will be able to check the presence of the embryo during the ultrasound and the beating of its heart – this is the final confirmation of the pregnancy.
Beta hCG test – norm and blood result
After implantation (implantation) of the embryo, there is a sharp increase in the concentration of chorionic gonadotropin. The level of beta hCG in pregnancy in the first weeks doubles in the blood every 48 hours or so. Based on this, the gestational age can be estimated at an early stage of gestation. However, this is not a precise measurement and should not be used to estimate the date of delivery.
An increase in the concentration of beta hCG in the blood above 5 mlU/ml can indicate pregnancy, however, it is the result of more than 25 mlU/ml that indicates a high probability of pregnancy. However, when the value is below 5 mlU/ml, it can be ruled out. It is also worth knowing that in the case of multiple pregnancies, the level of this hormone sometimes tends to be higher even at an early stage.
Beta hCG result at 1. week of pregnancy
It is assumed that the result of beta hCG at 3. Week of pregnancy ranks between 5 and 50 mlU/ml. Most often in the sources you can find a range that includes the level of chorionic gonadotropin just from this point. It is also worth knowing that from about 13. to 16. Week of pregnancy this result begins to decline, but it should not worry the mother-to-be. This is because it is important to maintain an appropriate increment, which is as follows:
- beta hCG result at 4. Week of pregnancy most often ranges from 5 to 425 mlU/ml,
- beta hCG result at 5. Week of pregnancy are already values from 18 to 7340 mlU/ml,
- The 6th week of pregnancy – from 1080 to 56500 mlU/l,
- 7. and The 8th week of pregnancy – from 7650 to 229,000 mlU/ml,
- 9 onwards. to 12. Week of pregnancy – from 25,700 to 288,000 mlU/ml,
- In the period of 13. to 16. Week of pregnancy – from 13,300 to 254,000 mlU/l,
- 17. to 24. Week of pregnancy – from 4060 to 165,400 mlU/l,
- 25 onwards. up to 40. Week of pregnancy – from 3640 to 117 mlU/ml.
Based on the above information, it can be noted that the highest concentration of beta hCG in the blood appears around 10. Week (between the 9th and 12th).
How to prepare for the beta hCG pregnancy blood test?
Preparing to test beta hCG hormone levels from blood is relatively simple. Although it is not a requirement, it will be a good idea to proceed on an empty stomach, which means avoiding eating and drinking for about 8-12 hours before the blood draw.
It is also recommended to perform the test in the morning (although it is not mandatory), before taking any medications – if the attending physician agrees. So if there is a need to take medication immediately upon waking up, consult your doctor for details. More often than not, however, they are not an obstacle to performing this test.
See also: 28 weeks of pregnancy – movements of the baby in the pit of the abdomen. What does a baby look like at 7 months pregnant?
Abnormal increase in beta hCG
It is important to remember that a positive pregnancy test and a blood test indicating elevated levels of chorionic gonadotropin are not equivalent to a diagnosis of a properly developing pregnancy. This is because the concentration of beta hCG can also increase in ectopic pregnancy or mycetoma, among other conditions. For this reason, any result should be interpreted by a specialist and supplemented by an ultrasound examination.
In addition, an abnormal increase or decrease in beta hCG can indicate a miscarriage, among other things, and also suggest chromosomal aberrations during the first trimester. In addition, beta hCG increases in the course of certain cancers.
Beta hCG in pregnancy vs ultrasound
A positive pregnancy test result is only a probable sign of pregnancy, which should always be confirmed by an ultrasound. Often, however, despite a positive pregnancy test, it is difficult for the gynecologist to locate a pregnancy follicle in the first weeks of pregnancy.
Theoretically, it should be visible in the uterus when the beta hCG concentration is greater than 1200 mlU/ml. In turn, the baby’s heart activity is visible when the concentration of chorionic gonadotropin reaches about 10 thousand mlU/ml. If, despite high levels of chorionic gonadotropin, the uterine cavity does not contain a pregnancy follicle, this may suggest a miscarriage or ectopic pregnancy. In most cases, however, the doctor asks the woman to come in again for an appointment a week or two later and locates a properly developing pregnancy.
FAQ
- What is beta hCG and what role does it play during pregnancy?
Beta hCG, or beta subunit of chorionic gonadotropin, is a hormone produced by syncytiotrophoblast cells during pregnancy. It facilitates the maintenance of pregnancy and conditions its normal development, mainly by stimulating the corpus luteum to produce progesterone. Therefore, an elevated beta hCG test result can indicate pregnancy.
- When is the best time to test beta hCG blood levels?
The beta hCG blood test is best taken about 8-10 days after conception, even before the date of expected menstruation, as this allows early detection of pregnancy. The blood test can be performed both on an empty stomach and after eating a meal. It will also be a good idea to report to them in the morning, although this too is not a necessity.
- What elevated levels of beta hCG in the blood indicate a high probability of pregnancy?
A blood beta hCG concentration of more than 25 mlU/ml indicates a high probability of pregnancy, while a value of less than 5 mlU/ml helps rule out pregnancy. However, pregnancy should always be confirmed by an ultrasound with a gynecologist.
- How do beta hCG levels change during pregnancy?
Beta hCG result at the 2nd week of pregnancy may not yet be invisible, as the scope covers the period from the The 3rd week – the hormone is at a level of 5 to 50 mlU/ml. Later it increases, hence the hCG beta result at 6. Week of pregnancy is up to 56500 mlU/l. The highest concentration of beta hCG occurs from 9. to 12. Week and reaches values as high as 288,000 mlU/ml.
Read also:
Blood pregnancy test-when to perform?
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