The hormone beta-HCG (chorionic gonadotropic hormone) is produced in early pregnancy when the egg begins to nest. What is its evolution during pregnancy? Per week ? How to interpret a low or high rate? Table of standards, dosing process, calculation…
L’beta-HCG hormone (chorionic gonadotropic hormone) is commonly referred to as “pregnancy hormone. Why ? Because it is produced at the very beginning of pregnancy after conception. What level of HCG to say that a woman is pregnant? Which is his evolution during pregnancy? Per week ? Why is it important to monitor its rate during pregnancy ? How is an HGC hormone assay performed? How to interpret the results of the analysis? Answers and table of values.
Definition: what is the beta-HCG hormone?
“L’chorionic gonadotropic hormone (also called beta-HCG hormonehuman chorionic gonadotropin) is a hormone secreted by the chorion (outer membrane of theembryo which ensures contact with the uterine mucosa: this is what will be the future placenta) in early pregnancy. This hormone begins to be produced when there is a implantation egg in the uterine lining“, explains Dr. Thierry Harvey, gynecologist and head of the Deaconesses maternity ward in Paris. Being at a sufficient concentration only during pregnancy, the beta-HCG hormone is therefore secreted only in pregnant women, from the beginning of the development of the embryo around the 10th day of pregnancy. This hormone is mainly used to maintain the corpus luteum, an endocrine gland located inside the ovary responsible for the secretion of progesterone and estrogen during the first trimester of pregnancy. It is detectable in urine and blood throughout pregnancy, but at extremely variable rates. Finally, in very rare cases, “this hormone can be secreted in individuals (men or women) suffering from ovarian pathologies such as certain types of ovarian or testicular tumours. This is also the only case where a pregnancy test is positive in a man“, adds the expert.
It peaks between the 7th and 12th week of pregnancy.
What is plasma beta-HCG hormone?
The level of this hormone in the blood (commonly called plasma beta-HCG or serum beta-HCG) increases steadily and gradually during the first 8 weeks of pregnancyand doubles every 48 hours. It reaches a peak between the 7th and 12th week of pregnancy. Generally around the 4th month of pregnancy, the rate gradually decreases until the end of pregnancy. After childbirth, the beta-HCG hormone gradually decreases in the woman’s body, until it disappears completely. The rates below are indicative values. Best to send the results to the prescribing doctor, your midwife, your gynecologist or the doctor of the analysis laboratory.
What is the beta-HCG hormone calculation?
The beta-HCG hormone doubles approximately every 48 hours during early pregnancy. To calculate the HCG hormone level in the blood, you need to know the result of the first HCG level analysis. Based on this rate, the calculator below will estimate whether or not you are pregnant, and for how long. (Level obtentionido de hCG: beta-HCG level)
Table of the evolution of beta-HCG during pregnancy (by week)
| Day/Week of pregnancy | Average beta-HCG level (in mIU/L) |
|---|---|
| 0 | Less than 5 |
| 7 days | Between 5 and 20 |
| 2nd week | Between 100 and 6,000 |
| 3rd week | Between 1,500 and 25,000 |
| 4th week | Between 2,400 and 70,000 |
| 5th week | Between 10,000 and 130,000 |
| 6th week | Between 30,000 and 190,000 |
| 7th week | Between 35,000 and 160,000 |
| 8th week | Between 25,000 and 140,000 |
| 2-3 months | Between 30,000 and 100,000 |
| 17-24 weeks (4-6 months) | Between 10,000 and 30,000 |
| Beyond the 25th week (7-9 months) | Between 5,000 and 15,000 |
| No pregnancy | < 15 mIU/mL |
When and why should a beta-HCG hormone assay be prescribed?
If in theory, for a normal pregnancy, the plasma beta-HCG hormone assay is not helpfulmost maternities recommend having a plasma dosage of the so-called qualitative beta-HCG hormone either to confirm the pregnancy or to ensure that it is going well. Note that this dosage is much more precise and reliable than a urine pregnancy test (a positive pregnancy test does not systematically confirm the certainty of a pregnancy, on the other hand, if the woman is pregnant, the level of HCG exceeds the 5IU/L in the blood at nesting). Only the dosage of HCG makes it possible to confirm or invalidate a pregnancy and to date with precision the beginning of the pregnancy. “On the other hand, if the pregnant woman has bleeding during her pregnancy, we will then prescribe an ultrasound as well as a dosage of the hormone beta-HCGwhich will allow us to know a little more about her pregnancy: is there a risk of miscarriage ? Is this an ectopic pregnancy? Is it a multiple pregnancy (twins, triplets…)?… In this case, the dosage will be quantitativethat is to say that this examination will give a figure that will have to be interpreted, knowing that for a normal pregnancy, the beta-HCG hormone level doubles every 48 hours“, explains the gynecologist. It is also possible to prescribe a dosage of the hormone beta-HCG to detect possible chromosomal abnormalities (in the event of screening for trisomy 21, in this case the level of HCG is higher than what is normally expected. These results will have to be combined with other markers), or the tumors of the placentawhich are very rare.
When performed on medical prescription, it is fully covered by Social Security. Don’t forget to bring your medical prescription as well as your vital and health insurance cards.
► The examination is first prescribed by a doctor duringa consultation in a practice or in the hospital. Beta-HCG hormone dosage is done in a medical analysis laboratory.
► After having installed you and having set up a tourniquet, the doctor measures the plasma level of the hormone beta-HCG which consists of into a collection of one or more tubes of blood (they usually contain 5 ml of blood each).
► After the sample, pressure will be applied for a few minutes on the puncture site.
► This tube will then be analyzed and the results will be sent to you between 24 and 48 hours after collection through a mail. Whatever the results (whether they seem abnormal or not), it is advisable to send them to the prescribing doctor who can decide, depending on the results, whether or not to carry out additional examinations.
► There are no particular indications at the end of this examination: you can eat and live normally.
Do you have to be fasting for the beta-HCG hormone assay?
It is not no need to fast to perform a beta-HCG hormone assay.
What is the normal level of the HCG hormone?
| Normal HCG level | |
|---|---|
| Children and Men | less than 1 IU/L |
| Women who ovulate | less than 2 IU/L |
| postmenopausal women | less than 7 IU/L |
| Pregnant women (10th day after fertilization) | Above 5 IU/L, but usually between 8 and 10 IU/L |
What does a negative beta-HGC mean?
It is considered that the beta-HCG assay is negative if the obtained value is less than 5 IU/L. This means that the woman is not pregnant.
What does a positive beta-HGC level mean?
It is considered that the beta-HCG assay is positive when the value obtained is greater than 5 IU/L. This means that the woman is pregnant.
What does low beta-HCG mean?
In the event of a miscarriage, the level of the hormone beta-HCG collapses (remember that in the event of a normal pregnancy, the level of the beta-HCG hormone is supposed to double every 48 hours, then stagnate around the end of the third month of pregnancy). Otherwise, “in ectopic pregnancy (the egg attaches to one place, but does not settle in the uterus), beta-HCG levels are significantly lower than normal levels for the corresponding week of pregnancy. Depending on the HCG level, we will prescribe a drug treatment (an equivalent of chemotherapy) and above all, we will monitor the decline of these hormones“, assures the gynecologist.
What does high beta-HCG mean?
► A molar pregnancy. A beta-HCG level that increases exponentially (100,000 IU/L, 200,000 IU/L and more) may be a sign of a molar pregnancy (this is very rare). The mole is a benign tumor with malignant potential which is an overdevelopment of placental cells: no embryo is visible because the uterus is filled with these small cells. Namely that an ultrasound is always prescribed to confirm or not the molar pregnancy. After the removal of the mole, it will be necessary to monitor that the HCG level reaches 0 and that it does not increase again, which could be a sign of a recurrence of mole or choriocarcinoma (cancer of the placenta occurring during a pathological pregnancy)
► A multiple pregnancy (twins…). In a multiple pregnancy, the beta-HCG level is much higher than in a single pregnancy. However, a high rate does not necessarily confirm that it is a multiple pregnancy. Only an ultrasound can reliably confirm a multiple pregnancy. Finally, “if the multiple pregnancy is confirmed, these women are immediately offered non-invasive screening for trisomy 21“, concludes Dr. Harvey.
What HCG hormone level in case of miscarriage?
In the event of a miscarriage, the level of the hormone beta-HCG collapses. We can observe one or more dosages repeated every 48 hours which show decreasing values (by about 50% every 12 hours), whereas the levels should increase.
A extra pregnancy–uterine (GEU) is the term used when the fertilized egg develops outside the uterus. “In the event of an ectopic pregnancy, the beta-HCG levels are significantly lower than the normal levels for the corresponding week of pregnancy. Depending on the HCG level, we will prescribe a drug treatment (an equivalent of chemotherapy) and above all, we will monitor the decline of these hormones“, indicates the gynecologist.
On the health forum: discussions about the level of beta-HCG
To remember
► The beta-HCG hormone is secreted only in pregnant women around the 10th day of pregnancy.
► The level of beta-HCG increases until the end of the 3rd month of pregnancy then stagnates and decreases until the end of pregnancy.
► Only the dosage of HCG can confirm or invalidate a pregnancy.
► It is not no need to fast to perform a beta-HCG hormone assay.
► In the event of a miscarriage, the level of the hormone beta-HCG collapses.
Thanks to Dr. Thierry Harvey, gynecologist and head of the Deaconess Maternity, in Paris.