What is hCG?
HCG is human chorionic gonadotropin, known as "pregnancy hormone"."Chorionic" comes from the word "corium". The chorion is a structure formed (in part) by the outside of the embryo, the trophoblast (see image below) and that will help train future placenta.
The chorion begins to produce hCG when the embryo implants in the uterus, usually 8 to 10 days after conception. Therefore the detection of hCG in a woman's body indicates that occurred embryo implantation.
How do I know my level of hCG is normal?
The table above is very basic, but a more detailed set of tables where you can check if your value is in range. Tables are extracted from the data base Betabase:
Table of normal values of beta hCG in the first month of pregnancy
Chart doubling times the beta hCG during pregnancy
Time Table doubling of beta-hCG in multiple pregnancies
Chart beta hCG values for twin pregnancies
Surely you have noticed that there are values of beta hCG concentrations that are repeated in different periods of gestation. How so? Very simple: the table shows the full range of possible values that have been reported in the clinical literature in viable pregnancies and it happens that the range is very wide.
Let me explain better with an example: a pregnant woman three weeks (10 days after conception) may have 5 mIU / ml of hCG according to the table and having a viable pregnancy, but a different woman can reach 5 mIU / ml of hCG at 4 weeks and also be a viable pregnancy.
HCG is human chorionic gonadotropin, known as "pregnancy hormone"."Chorionic" comes from the word "corium". The chorion is a structure formed (in part) by the outside of the embryo, the trophoblast (see image below) and that will help train future placenta.
The chorion begins to produce hCG when the embryo implants in the uterus, usually 8 to 10 days after conception. Therefore the detection of hCG in a woman's body indicates that occurred embryo implantation.
Here you can see an outline of how the embryo to the uterus descends. When the embryo reaches the uterus begins implantation in the wall and begins the secretion of chorionic hormone hCG . The hormone passes the uterus to blood and blood into the urine. Blood tests measure the hCG in the blood, while home test measures the hCG in urine.
Proof of hCG can be qualitative or quantitative. A qualitative test when the only information you give us is whether or not, in this case, or no hCG. The pregnancy test urine tests are qualitative. Then a photograph of a test strip from urine pregnancy test is shown. The presence of two lines (the left one is less marked) indicates that if hCG and therefore, if no pregnancy. However, do not tell much hormone is not possible to estimate the length of pregnancy.
Instead, a quantitative test gives the exact value of concentration in this case, the concentration of hCG in the body. Testing of hCG in blood and quantitative tests are made in the clinic. Here you can see an example of analysis result in blood beta-hCG by chemiluminescence method . The value appears hCG obtained (581.22 mIU / ml) and the reference table where how many weeks pregnant shown corresponds to a given value of hCG. In the example would be 2-3 weeks.
Pregnancy test home in urine. Positive test.
When I can start doing the hCG test?
If the hormone begins to occur 8-10 days after conception, you can start testing blood or urine since. The test detects hormone blood a few days before.
However, should note that the urine test have different detection thresholds. This means that a detect hCG before others.
However, should note that the urine test have different detection thresholds. This means that a detect hCG before others.
For women undergoing a cycle of assisted reproduction clinics set deadlines for the first quantitative hCG beta test ::
- 12 days after the oocyte collection,
- 9 days after embryo transfer embryos / day 3 and
- 7 days after blastocyst transfer.
How do I know my level of hCG is normal?
This table is what most textbooks considered normal levels of hCG :
Time pregnancy hCG (mIU / mL)
3 weeks 5 a 50
4 weeks 5 a 426
5 weeks 19-7340
6 weeks 1080-56500
7 - 8 Weeks 7650-229000
The table above is very basic, but a more detailed set of tables where you can check if your value is in range. Tables are extracted from the data base Betabase:
Table of normal values of beta hCG in the first month of pregnancy
Chart doubling times the beta hCG during pregnancy
Time Table doubling of beta-hCG in multiple pregnancies
Chart beta hCG values for twin pregnancies
Let me explain better with an example: a pregnant woman three weeks (10 days after conception) may have 5 mIU / ml of hCG according to the table and having a viable pregnancy, but a different woman can reach 5 mIU / ml of hCG at 4 weeks and also be a viable pregnancy.
Therefore, an important point is that the values of beta hCG should be viewed only as guidelines and estimates, and can not be compared between a woman and another . Low numbers may be normal in women (eg in the case of embryos undergoing preimplantation diagnosis), a high value may be normal in another, and perfectly normal values can fool everyone.
In fact, what makes it so important measurement of hCG is not having a single value of hCG, but see it grow between two shots at a rate determined: it is called . doubling time of hCG doubling time is an estimate used by doctors to help measure the progress of a pregnancy at the beginning of it.
With a simple calculator like you have on this link ( calculator doubling time ) you can find out if your speed replication is appropriate.
In fact, what makes it so important measurement of hCG is not having a single value of hCG, but see it grow between two shots at a rate determined: it is called . doubling time of hCG doubling time is an estimate used by doctors to help measure the progress of a pregnancy at the beginning of it.
With a simple calculator like you have on this link ( calculator doubling time ) you can find out if your speed replication is appropriate.
Generally, the values of hCG will double every 48-72 hours. This means that if your beta hCG is 150 mIU / ml on Monday, should be about 300 mIU / ml between Wednesday and Thursday.
Once you have completed at least two or three quantitative tests hCG and your doctor says everything is on track, you can breathe easy.
My doubling time of hCG is low What is happening?
Sometimes a low doubling time at the beginning of the pregnancy does not mean anything. Sometimes, it's bad news.
Once you have completed at least two or three quantitative tests hCG and your doctor says everything is on track, you can breathe easy.
My doubling time of hCG is low What is happening?
Sometimes a low doubling time at the beginning of the pregnancy does not mean anything. Sometimes, it's bad news.
- A slow doubling time may mean that the embryo is not viable. You've done all you can do, and there's nothing you can do but wait. The embryo may have chromosomal abnormalities that prevent it from being feasible.
- The pregnancy may be ectopic - outside the womb. An embryo can travel outside the uterus, one of the fallopian tubes, or even within the abdominal cavity. The pregnancy ectopic are rare, but do occur.
- A laboratory readings may have been an error. Never compare two values obtained in different laboratories.
- You may have had a vanishing twin brother. This occurs when two embryos implanted, and begin to produce hCG , but then one of them dies. It starts with "double" of hCG , and then drops the figure - but as the remaining embryo grows, the doubling time returns to normal again.
However, a sharp drop in your beta hCG usually means you're having a spontaneous abortion . Keep hope until your doctor tells you otherwise, it is not always the case.
The hCG can start with higher or lower values of normal. If there has been an intrauterine insemination or in a pregnancy naturally you can not know your ovulation date. Without knowing the date of ovulation, it may happen that the test of hCG is done ahead of time or after time and is lower or higher than expected.
Many times, when the rate of duplication between the first and second test is slow, is usually performed third and sometimes even fourth test hCG at intervals of two days between them. Failure to turn in the test third and / or fourth is a poor prognostic sign.Generally indicates a failed or "dysfunctional" implementation. In some cases, slow doubling time may indicate a tubal pregnancy (ectopic). To verify the existence of ectopic pregnancy , the doctor will do further tests hCG, ultrasound and will monitor your health for any signs or symptoms of an ectopic pregnancy .
Many times, when the rate of duplication between the first and second test is slow, is usually performed third and sometimes even fourth test hCG at intervals of two days between them. Failure to turn in the test third and / or fourth is a poor prognostic sign.Generally indicates a failed or "dysfunctional" implementation. In some cases, slow doubling time may indicate a tubal pregnancy (ectopic). To verify the existence of ectopic pregnancy , the doctor will do further tests hCG, ultrasound and will monitor your health for any signs or symptoms of an ectopic pregnancy .
Another reason for a beta hCG low is that some embryos have what is called a " delayed implantation ". Usually, an embryo begins to implant and your body begins to produce hCG 8-10 days past conception. But the embryo may take a few days to make the implementation and hCG does not appear at the expected time. It takes patience, hope and repeat the test last few days.
Some research shows that frozen embryos are slower than fresh embryos. So if you made a frozen embryo transfer, maybe your hCG is somewhat lower oo the slower replication.
Some research shows that frozen embryos are slower than fresh embryos. So if you made a frozen embryo transfer, maybe your hCG is somewhat lower oo the slower replication.
Your hCG may be low due to a very early miscarriage. It is estimated that up to 25% of pregnancies end in miscarriages early - but researchers are not sure.
Finally, an important caveat: if you're going to make two consecutive analysis to calculate the doubling time of your beta-hCG, make them in the same clinic. Different clinics may have different measuring and comparing the values of each other, never or almost never true. There is a mess when it relates to apparatus for measuring the hCG beta and although the World Health Organization tries to bring order, establishing systems for calibration of apparatus, the differences are obvious. This is a scientific article about:
What is a biochemical pregnancy?
Finally, an important caveat: if you're going to make two consecutive analysis to calculate the doubling time of your beta-hCG, make them in the same clinic. Different clinics may have different measuring and comparing the values of each other, never or almost never true. There is a mess when it relates to apparatus for measuring the hCG beta and although the World Health Organization tries to bring order, establishing systems for calibration of apparatus, the differences are obvious. This is a scientific article about:
Differences in Recognition of the 1st WHO International Reference Reagents for hCG-Related Isoforms by Diagnostic Immunoassays for Human Chorionic Gonadotropin. Clinical Chemistry
August 2009 vol. 55 no. August from 1484 to 1491What is a biochemical pregnancy?
A biochemical pregnancy is one where, despite beta hCG test is "positive", the embryo fails to progress to the point of confirmation by ultrasound. The placenta is producing hCG, but there is no embryo. The biochemical pregnancies occur quite often after IVF. Although usually usually the result of a chromosomal abnormality in the embryo, it can also be due to anatomical problems in the uterus, or other immune problems. For IVF patient, the diagnosis of a " biochemical pregnancy "represents a serious disappointment. However, their appearance provides clear evidence that at least one embryo reached an advanced stage of preimplantation development (blastocyst stage), hatched and tried to implant, which is a clear hope for a pregnancy standard in the future.
My hCG is very high What can be happening?
My hCG is very high What can be happening?
When hCG is very high, the causes can be:
- Multiple pregnancy . Was it the transfer of 2 or more embryos?
- Spontaneous twins. Sometimes the embryo is removed and identical twins are obtained. Identical twins (division of an embryo) are not as typical in
- A pregnancy molar. These cases are very rare; do not worry about this unless your doctor tells you.
When hCG tests are done?
When the beta hCG is between 1,000-2,000 mIU / ml, the gestational sac usually can see through the transvaginal ultrasound and end determinations of hCG . From that moment, the risk of miscarriage is usually less than 15% in women under 39 years of age and under 35% in women over forty years.
What happens if you're still only a value of hCG and have doubts?
Do not give too much thought to the head. Neither scientists agree on how predictive value may have one shot. This article ( Beta hCG to day 14 predicts the outcome of pregnancy ) you can see a summary of studies that show a certain predictability of a single value of beta hCG . What is important as you will see, is that there is a margin of error, it is risky to predict anything with a single value, if you do not know the exact date of fertilization.
What happens if you're still only a value of hCG and have doubts?
Do not give too much thought to the head. Neither scientists agree on how predictive value may have one shot. This article ( Beta hCG to day 14 predicts the outcome of pregnancy ) you can see a summary of studies that show a certain predictability of a single value of beta hCG . What is important as you will see, is that there is a margin of error, it is risky to predict anything with a single value, if you do not know the exact date of fertilization.