The hormone beta-HCG (chorionic gonadotropic hormone) is produced early in pregnancy when the egg begins implantation.
All pregnant women look at its rate. The beta-HCG hormone (Chorionic Gonadotropic hormone) is produced only in a pregnant woman, at the very beginning of pregnancy after conception. The beta-HCG hormone is measured in a medical analysis laboratory, only with a medical prescription. It is based on a blood test (it is not necessary to fast). The results are transmitted between 24 and 48 hours after the sample by mail. Whatever the results (whether they seem abnormal to you or not), it is advisable to send them to the prescribing doctor who can decide whether or not to carry out additional tests. There are no particular indications at the end of this examination: you can eat and live normally.
Definition: what is the beta-HCG hormone?
“Chorionic gonadotropic hormone (also called beta-HCG hormone, human chorionic gonadotropin) is a hormone secreted by the chorion (outer membrane of the embryo which ensures contact with the uterine mucosa: this is what will be the future placenta) at the start of pregnancy. This hormone begins to be produced when there is implantation of the egg in the uterine lining“, explains Dr Thierry Harvey, gynecologist and head of the Diaconesses maternity ward, in Paris. The beta-HCG hormone is therefore secreted only in pregnant women, from the start of embryo development around the 10th day of pregnancy This hormone mainly serves 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. detectable in urine and blood throughout pregnancy, but at extremely variable levels. In very rare cases, “this hormone can be secreted in individuals (male or female) suffering from ovarian pathologies such as certain types of ovarian or testicular tumors. This is also the only case where a pregnancy test is positive in a man“, adds the expert.
What is the plasma beta-HCG hormone?
The level of this hormone in the blood (commonly called plasma beta-HCG or serum beta-HCG) increases regularly and gradually during the first 8 weeks of pregnancy, and doubles every 48 hours. It peaks between the 7th and 12th weeks of pregnancy. Generally around the 4th month of pregnancy, the rate gradually decreases until the end of the pregnancy. After childbirth, the beta-HCG hormone gradually declines in the woman’s body, until it disappears completely. The rates below are indicative values. It is best to send the results to the prescribing doctor, your midwife, your gynecologist or the doctor at the analysis laboratory.
How is the beta-HCG hormone calculated?
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 you are pregnant or not, and for how long. (HCG level obtained: beta-HCG level)
Table of changes in beta-HCG during pregnancy (per 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 you prescribe a beta-HCG hormone dosage?
If in theory, for a normal pregnancy, the plasma dosage of the beta-HCG hormone is not useful, most maternity hospitals recommend doing a so-called qualitative plasma dosage of the beta-HCG hormone either to confirm the pregnancy, or to ensure its smooth running. Please 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, however, if the woman is pregnant, the HCG level exceeds the 5UI/L in the blood at implantation). Only the HCG dosage makes it possible to confirm or deny a pregnancy and to accurately date the start 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 beta-HCG hormone, which will allow us to know a little more about her pregnancy: y Is there a risk of miscarriage? Is this an ectopic pregnancy? Is it a multiple pregnancy (twins, triplets, etc.)?… In this case, the dosage will be quantitative, that 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 beta-HCG hormone to detect possible chromosomal abnormalities (in the case of screening for trisomy 21, in this case the HCG level is higher than what is is normally expected. These results will have to be combined with other markers), or placental tumors, which are very rare.
What is the normal level of the HCG hormone?
The HCG level measures the concentration of the pregnancy hormone, the hormone gonadotropin. Its rate is at its maximum in the 3rd month of pregnancy. The HCG level will then gradually decrease until delivery.
| Normal HCG level | |
|---|---|
| Children and Men | less than 1 IU/L |
| Women who ovulate | less than 2 IU/L |
| Menopausal women | less than 7 IU/L |
| Pregnant women (10th day after fertilization) | Above 5 IU/L, but generally between 8 and 10 IU/L |
What does a negative beta-HGC level mean?
The beta-HCG dosage is considered negative if the value obtained is less than 5 IU/L. This means that the woman is not pregnant.
What does a positive beta-HGC level mean?
The beta-HCG dosage is considered positive when the value obtained is greater than 5 IU/L. This means that the woman is pregnant.
What does low beta-HCG mean?
From the start of pregnancy, the level of the beta-HCG hormone is supposed to double every 48 hours. It evolves until reaching a peak in the 3rd month of pregnancy then it stabilizes and gradually decreases until delivery. Apart from this normal development, it can drop quickly:
→ in case of miscarriage
→ in case of 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 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) can be a sign of a molar pregnancy (this remains 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. Please note that an ultrasound is always prescribed to confirm or not the molar pregnancy. After the elimination 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 the mole or of choriocarcinoma (cancer of the placenta). occurring during a pathological pregnancy)
► A multiple pregnancy (twins…). In multiple pregnancies, 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 will reliably confirm a multiple pregnancy. Finally, “if the multiple pregnancy is confirmed, these women are immediately offered non-invasive screening for Down syndrome“, concludes Dr. Harvey.
What level of HCG hormone in case of miscarriage?
In the event of a miscarriage, the level of the hormone beta-HCG plummets. We may observe one or more dosages repeated every 48 hours which show decreasing values (by approximately 50% every 12 hours), when the levels should be increasing.
A extra pregnancy–uterine (GEU) is the term used when the fertilized egg develops outside the uterus. “In the event of an ectopic pregnancy, beta-HCG levels are significantly lower than normal levels for the corresponding week of pregnancy. Depending on the HCG level, drug treatment (an equivalent of chemotherapy) will be prescribed and, above all, we will monitor the decline of these hormones“, indicates the gynecologist.
On the health forum: discussions about the beta-HCG level
To remember
► The beta-HCG hormone is secreted only in pregnant women around the 10th day of pregnancy.
► The beta-HCG level increases until the end of the 3rd month of pregnancy then stagnates and decreases until the end of the pregnancy.
► Only the HCG dosage can confirm or deny pregnancy.
► It is not necessary to be fasting to perform a beta-HCG hormone assay.
► In the event of a miscarriage, the level of the beta-HCG hormone collapses.
Thanks to Dr Thierry Harvey, gynecologist and head of the Diaconesses maternity ward in Paris.
