Call
1 800 545.2254
contact a blood Work represenatative

Human chorionic gonadotropin (HCG) Blood Test

Be the first to review this product

Availability: In stock

$5.00
OR

Quick Overview

Human chorionic gonadotropin (HCG)


What Is hCG?
Human chorionic gonadotropin (hCG) is a glycoprotein hormone that is normally produced first by the cells that make up the placenta, then later by the placenta during pregnancy. Its primary function is to support the pregnancy by encouraging the production of progesterone. This supports and promotes the further development of the placenta early in pregnancy. hCG sees a rapid increase early in pregnancy, but tapers off slowly as the placenta can produce enough progesterone to support the pregnancy on its own. The glycoprotein also serves in aiding in the development of gonads in the fetus and the production of androgens by the testes of a male fetus.

Human chorionic gonadotropin (HCG) Blood Test

Double click on above image to view full picture

Zoom Out
Zoom In

More Views

Details

Human chorionic gonadotropin (HCG)

What Is hCG?
Human chorionic gonadotropin (hCG) is a glycoprotein hormone that is normally produced first by the cells that make up the placenta, then later by the placenta during pregnancy. Its primary function is to support the pregnancy by encouraging the production of progesterone. This supports and promotes the further development of the placenta early in pregnancy. hCG sees a rapid increase early in pregnancy, but tapers off slowly as the placenta can produce enough progesterone to support the pregnancy on its own. The glycoprotein also serves in aiding in the development of gonads in the fetus and the production of androgens by the testes of a male fetus.

Levels of hCG can first be detected approximately 11 days following conception, in a blood test. One to three days later, it can be detected with a urine test. Some highly sensitive tests can detect hCG as early as a week following ovulation. Normal home pregnancy tests are not able to detect hCG in the blood until at least 12 to 14 days after ovulation.
A typical pregnancy should have levels of hCG doubling every 48 to 72 hours up to the eighth to 11th week, at which time they start to stabilize and remain constant for the duration of the pregnancy. This occurs in about 85% of pregnancies. When hCG levels become high, they will start to double every 96 hours.
Pregnant women, especially those who have experienced fertility issues, place a lot of importance on hCG levels. Due to vast ranges of what can be normal, doctors advise women to not take them too seriously. Some women have low hCG levels and go on to have a healthy, normal baby.
Levels of the hCG in the blood are measured in milli-international units per millimeter (mIU/ml). Anything under 5mIU/ml registers as negative on a pregnancy test, while a level over 25mIU/ml is positive. Ultrasounds have proven much more accurate in diagnosing and predicting the viability of a pregnancy than hCG levels. hCG levels can be tested in two ways: qualitative tests determine whether it exists in the blood or urine, while quantitative tests measure how much is in the bloodstream.
Description: C:\Documents and Settings\Administrator\Desktop\pregb.JPG
A gestational sac usually completes its formation once hCG levels reach 1,200 mIU/ml. If an hCG reading is low or falling, it could signal a more recent pregnancy than previously thought, a mother who has had or is experiencing a miscarriage or blighted ovum, or an ectopic pregnancy. Higher levels than what is considered normal for the age of the pregnancy can mean that the pregnancy is further along than estimated, that there is a molar pregnancy present, or that multiple pregnancy or ovarian cancer exists.
After a miscarriage, hCG levels fall back to the pre-pregnancy range, which is less than 5.0 mIU/ml, about four to six weeks later. In some fertility treatment regimens, women may receive hCG injections to encourage ovulation or to extend the luteal phase of the cycle. When hCG is given during pregnancy, its purpose is to stimulate progesterone to further support the pregnancy. The effectiveness of this practice, however, is controversial at this time.
Hcg Treatment

  • Women with uterine problems are also not considered good candidates for HCG treatments, because the uterus can be overstimulated, leading to a bleeding, thicker lining, and other uterine abnormalities.
  • This can be life threatening and causes symptoms like very severe pelvic pain, diarrhea or nausea, swelling of the hands, legs, feet and stomach, shortness of breath, and low urination output. If you have just started HCG treatments and you develop these symptoms, contact your doctor immediately.

Description: C:\Documents and Settings\Administrator\Desktop\ab9228_1.JPG
Low Hcg

  • Due to vast ranges of what can be normal, doctors advise women to not take them too seriously. Some women have low hCG levels and go on to have a healthy, normal baby. Levels of the hCG in the blood are measured in milli-international units per millimeter (mIU/ml).
  • Though there is a connection between HCG levels and ectopic pregnancy, low, slow-to-rise, and declining HCG levels do not always indicate an ectopic pregnancy. Sometimes low HCG levels may simply mean a pregnancy is not as far along as originally thought.

 

Hcg Levels

  • By comparison, urine pregnancy tests and and qualitative blood tests only detect the presence of hCG, but they are generally not sensitive enough to read levels below a certain amount. Beta hCG levels are therefore highly recommended for verifying a pregnancy as early as possible, and for checking on the health of a known pregnancy by ensuring that the readings of hCG are normal.
  • This type of pregnancy usually ends on its own, or needs to be ended medically in order to prevent harm to the mother, such as internal bleeding. Clearly, keeping up with hCG levels, especially prior to six weeks, can tell a lot about how a pregnancy will likely progress.

Hcg Diet

  • Raw vegetables like spinach and onions can be placed into egg whites for a low-calorie breakfast omelet. Many HCG diet recipes call for an individual to eat many vegetables throughout the low-calorie phase of the diet, as vegetables provide an ample amount of nutrition with very little effect on blood sugar levels.
  • Most fats are excluded from the diet for their caloric density, as are sugars and processed foods. Exercise is acceptable and recommended by most physicians who practice the HCG diet, but it isn't mandatory, especially for those with low energy during the calorie deprivation stage.

Ivf Hcg

  • There are many procedures which can be involved in in vitro fertilization (IVF). Eggs must be harvested, sperm cells collected, and the two are combined to create an embryo.
  • Blood is tested to check for appropriate estrogen levels, and the transvaginal ultrasound measures the size of the egg follicles. Day 16 of the IVF schedule includes the human chorionic gonadotropin (HCG) injection. The HCG injection is used to help the eggs reach maturation.

Hcg Hormone

  • It is said that a person on the diet can experience weight loss of about one or more pounds (about .45 kg) a day without exercising. The hormone, hCG, is secreted by cells in the placenta in pregnant women. About 11 days after conception, the hormone can be found via blood test.
  • one function in mind — to test urine for the presence of the pregnancy hormone, HCG.

Hcg

  • According to the details of the homeopathic hCG diet, only light to moderate exercise is required. Human chorionic gonadotrophin (hCG) is a protein-like hormone produced by a woman's body when she is pregnant.
  • This may also make recognizing early pregnancy symptoms harder. Additionally, because HCG is the hormone detected by home pregnancy tests, testing may be inaccurate if it is performed too soon.

Human Chorionic Gonadotropin Hcg

  • Doctors may prescribe human chorionic gonadotropin, or HCG, to treat various medical conditions related to the reproductive system. Just like most other types of medication, this treatment features some side effects, and they tend to differ in men and women.
  • Human chorionic gonadotropin (HCG) is a hormone produced when women are pregnant, and in some rare instances when certain tumors develop. In most cases, pregnancy tests look for the presence of this hormone.

Beta Hcg Levels

  • By comparison, urine pregnancy tests and and qualitative blood tests only detect the presence of hCG, but they are generally not sensitive enough to read levels below a certain amount. Beta hCG levels are therefore highly recommended for verifying a pregnancy as early as possible, and for checking on the health of a known pregnancy by ensuring that the readings of hCG are normal.
  • In these cases, false positive tests can be fairly common. As pregnancy progresses, HCG levels rise dramatically. Early on in the pregnancy, they can easily double every few days.

Description: C:\Documents and Settings\Administrator\Desktop\9103.jpg

 

Urine Hcg

  • About 11 days after conception, the hormone can be found via blood test. After 12-14 days, it can show up in urine and is often used to detect pregnancy. One of the purposes of the hormone is to help the body get fat ready for use in order to provide energy for the pregnant woman and her developing baby.
  • Most home pregnancy tests screen for the amount of human chorionic gonadotropin, or hCG, in the urine, as this is the major indicator of pregnancy. While the minimum amount of hCG required for any pregnancy is about 5 mIU/ml, hCG levels in early pregnancy vary greatly.

Normal Hcg Levels

  • This type of pregnancy usually ends on its own, or needs to be ended medically in order to prevent harm to the mother, such as internal bleeding. Clearly, keeping up with hCG levels, especially prior to six weeks, can tell a lot about how a pregnancy will likely progress.
  • If levels go down or stay the same, this could indicate an early miscarriage. Doctors do not normally perform routine tests to check beta hCG levels in detected pregnancies unless a problem is suspected.

What Are Beta hCG Levels?
Beta human chorionic gonadotropin (hCG) testing refers to a blood test that can read the exact levels of hCG in a woman's blood. This can also be called a quantitative hCG test, and it is the most accurate test available for detecting pregnancy in its earliest stages. By comparison, urine pregnancy tests and and qualitative blood tests only detect the presence of hCG, but they are generally not sensitive enough to read levels below a certain amount. Beta hCG levels are therefore highly recommended for verifying a pregnancy as early as possible, and for checking on the health of a known pregnancy by ensuring that the readings of hCG are normal.
Description: C:\Documents and Settings\Administrator\Desktop\F1.medium.gif
HCG is a hormone produced by cells which will become the placenta and is needed to alert the body that a pregnancy has occurred. This tells the brain and ovaries not to secrete additional hormones to bring about a monthly menstrual period, but to instead begin supplying hormones to support the pregnancy and its needs. Beta hCG levels should be able to predict a pregnancy within a day or two of implantation, which generally occurs four to seven days after conception. Implantation is when the group of cells which will become the baby, placenta, and yolk sac embed into the lining of the uterus.
The exact beta hCG levels will vary widely from woman to woman and from pregnancy to pregnancy. For this reason, hCG levels should not be used to determine the gestational age of the embryo or to determine a pregnancy's viability unless being compared to previous results. In most cases, as long as beta hCG levels are going up and doubling approximately every 48 hours, the pregnancy is considered viable. If levels go down or stay the same, this could indicate an early miscarriage.
Doctors do not normally perform routine tests to check beta hCG levels in detected pregnancies unless a problem is suspected. Issues that warrant testing may include vaginal bleeding, severe cramping, or a past miscarriage in the mother. Tests may be taken to get hCG levels and then taken again two days later to ensure that the hormone levels are increasing at the appropriate rate. It should be noted, however, that in some cases hCG levels rise more quickly or slowly, even in healthy pregnancies. If beta hCG levels are rising at a slower than average rate, a trans-vaginal ultrasound may be the best way to determine whether or not the pregnancy is viable.

 

 

Human Chorionic Gonadotropin Pregnancy Test
Human chorionic gonadotropin (hCG) is a glycoprotein secreted by the placenta during pregnancy that consists of an alpha and beta subunit. The alpha subunit is structurally similar to the alpha subunits of FSH, LH and TSH. The beta subunit is distinct for hCG. The release of hCG into maternal circulation begins with embryo implantation 5 to 7 days after fertilization.
Several forms of hCG are present in serum and urine (Clinical Chemistry 1997; 43:2233 – 43). In early pregnancy, trophoblast cells of the placenta secrete predominantly intact hCG. This molecule is broken down into several degradation products. The normal degradation pathway is: Non-nicked hCG-à free alpha subunit & nicked free beta subunità beta core fragment
The proportion of nicked hCG can vary between 0 & 59% during the first trimester. In late pregnancy, the production of free alpha subunit increases.

Molecules in Serum

First Trimester

Third Trimester

Intact hCG

85%

25%

Nicked hCG

9%

20%

Free alpha subunit

5%

54%

Free beta subunit

0.9%

0.5%

Beta core

Undetectable

Undetectable

Weeks Gestation

Molecules in Urine

<5 weeks

Beta core < intact hCG

6 –7 weeks

Beta core = intact hCG

7 - 8 weeks

Beta core > intact hCG

>8 weeks

Beta core 3 x higher than intact hCG

 

The serum of patients with uncomplicated pregnancies contains

  • Intact hCG
  • Nicked hCG (degradation product)
  • Free alpha subunit (hyperglycosylated & not incorporated into hCG)
  • Free beta subunit

Urine contains all of the above plus beta core fragment. Abnormal pregancies (Down syndrome, pre-eclampsia, etc) produce much greater and more variable proportions of nicked hCG, free beta subunit, and beta core fragment.
Commercial assays use any of 7 antibody combinations that may detect:

  • Only non-nicked hCG
  • Non-nicked hCG & free beta subunit
  • Non-nicked hCG & nicked hCG
  • Non-nicked hCG, nicked hCG & free beta subunit

The performance of urine pregnancy tests has improved dramatically in the last several years. Previous agglutination tests had a sensitivity of 500U/L. Current qualitative urine tests, based on enzyme immunoassay techniques, become positive when hCG concentrations reach 20 to 25 IU/L. Using first morning urine, pregnancy can usually be detected within the first week of a missed menstrual period . Variability in the ability of different home pregnancy tests to detect early pregnancy is largely due to differences in sensitivity (20 vs 25 IU/L), lack of standardization and varying degrees of sensitivity to hyperglycosylated hCG.
Quantitative serum hCG tests have a sensitivity of less than 10IU/L and can detect pregnancy two to four days earlier than a urine test. Healthy, non-pregnant women have serum hCG levels <5 IU/L. Serum hCG values >25 IU/L indicate pregnancy. Levels between 5 and 25 IU/L often indicate early pregnancy, but results need to be interpreted cautiously because false positive results can occur in this range. In this situation, the test should be repeated 48 hours later to confirm pregnancy. Serum hCG concentrations double every 1.5 to 2 days during the first 6 weeks of gestation in patients with uncomplicated intrauterine pregnancies.
Serum hCG levels can be used to estimate gestational age. Values for hCG generally peak between 8 to 12 weeks gestation and then gradually decline throughout the remainder of pregnancy.

 

 

Weeks from LMP

Serum hCG Range

3 – 4

9 – 130

4 – 5

75 – 2600

5 – 6

850 – 20,800

6 – 7

4,000 - 100,200

7 – 12

11,500 - 289,000

12 – 16

18,300 - 137,000

16 – 29

1,400 - 54,300

29 – 41

940 - 60,000

Estimates may differ by as much as 2 weeks from predictions based on menstrual history. Gestational dating by ultrasound is more accurate.
Serum hCG levels increase in perimenopausal (41-55 years) and postmenopausal (>55 years) women, because decreases in ovarian estrogen and progesterone production result in a lessening of the negative feedback control of gonadotropin releasing hormone (GnRH) by the hypothalamus. As a result, continuous GnRH stimulation of gonadotrope cells in the pituitary leads to increased LH and FSH production as well as pituitary hCG. Consequently, serum hCG levels as high as 8 IU/L and 15 IU/L may occur in nonpregnant perimenopausal and postmenopausal women, respectively. The hCG level should exceed 20 IU/L for pregnancy to be considered in this age group.
Quantitative serum hCG levels are helpful in evaluating suspected ectopic pregnancy because the classical triad of abdominal pain, delayed menses, and vaginal bleeding occurs in less than 20% of cases. Most ectopic pregnancies produce sufficient amounts of hCG to test positive with urine pregnancy tests. A urine pregnancy test can confirm that a woman is pregnant much faster and cheaper than a serum quantitative hCG. Serum hCG quantitation can then be done to determine if a fetus is large enough to be visualized by ultrasound. Gestational sacs are visible by transvaginal ultrasonography when serum hCG levels equal or exceed 1600 mIU/mL. If the hCG level is this high and no sac is visible in the uterus, ectopic pregnancy is suspected. Quantitation of serum hCG levels in paired specimens drawn 48 hours apart can also be used to help diagnose ectopic pregnancy. Women with uncomplicated pregnancies increase their serum hCG levels at least 1.6 fold during this interval. Smaller increments are consistent with ectopic or complicated pregnancy.
The circulating half-life of hCG is 24 hours.hCG may still be detectable in maternal serum 8 to 24 days after an uncomplicated vaginal delivery. Following a first trimester spontaneous abortion, serum hCG may be detectable up to 60 days.
A single serum hCG level 16 days after ovulation in women who became pregnant through assisted reproductive technology provides a useful predictor of pregnancy outcome. hCG levels above 500 IU/L predict a greater than 95% chance of ongoing pregnancy. Levels between 25 and 50 IU/L are associated with a less than 35% probability of ongoing pregnancy. (Fertil Steril 2000;73:260-74).
Urine pregnancy tests are reported as positive or negative. Reference value is negative.

Serum hCG reference range is :


Female, premenopausal

0 - 3 IU/L

Female, perimenopausal

0 – 15 IU/L

Male

0 - 3 IU/L

Specimen requirement for the urine pregnancy test is 10 mL of a first morning midstream urine collection in a urine specimen cup. Specimen requirement for quantitative serum hCG is one SST tube of blood.

What Is a Quantitative Blood Test?
When a woman becomes pregnant, her body begins to produce the hormone known as human chorionic gonadotropin (HCG) to form and maintain a placenta around the developing egg. A qualitative blood or urine test merely measures if HCG is present and is the common method of testing for pregnancy. A quantitative blood test, by contrast, will measure the levels at which HCG appears in order to determine the approximate due date and whether any abnormalities or miscarriage might occur.
HCG levels increase according to a fairly predictable time table until women are about five months pregnant, and then that level maintains until birth. According to the American Pregnancy Association, about 85 percent of pregnant women will have HCG levels that double every two or three days, until the end of the first trimester, when those levels start to take about four days to double. Since these numbers are fairly predictable, doctors can order a quantitative blood test to measure the probability of a variety of problems.
Description: C:\Documents and Settings\Administrator\Desktop\Early_placental_structure.jpg
The National Institutes of Health maintains a list of appropriate ranges of quantitative blood test levels, based on the range of weeks a woman has been pregnant. If the test reveals HCG levels that are too low, it could mean miscarriage, partial miscarriage or ectopic pregnancy, which means the fetus is developing outside the uterus. Another set of potential problems, or surprises, could be signaled if the levels are too high, from cancer and internal moles to twins or more than two fetuses developing concurrently.
A quantitative blood test is used in concert with other tests if Down Syndrome is suspected. It is also regularly used to determine a woman's due date before an ultrasound can more accurately determine this date. This test may go by several names, depending on the lab and doctor prescribing it. Serial beta HCG and repeat quantitative beta HCG are other common names for this test.
If a quantitative blood test reveals too high or too low HCG levels, doctors will start to hone in on the particular problem. Medical imaging and further blood tests might be ordered to identify the specific condition a patient is experiencing. Follow-up testing, particularly an ultrasound at five or six weeks, might reveal that no problems exist, since some women have abnormal HCG levels and give birth to healthy children.

Human Chorionic Gonadotropin (hCG) Blood Test
Definition
A qualitative HCG blood test checks to see if there is a hormone called human chorionic gonadotropin in your blood. HCG is a hormone normally produced during pregnancy.

Description
Human chorionic gonadotropin (hCG) is a dimer consisting of a 145 amino acid beta-subunit that is unique to hCG and a 92 amino acid alpha-subunit. The alpha-subunit is identical to that for luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH). The alpha and beta-subunits have separate genes on separate chromosomes (chromosomes 6 and 19, respectively). After synthesis, the alpha and beta-subunits are bonded with a noncovalent bond before being released into the circulation.
Carbohydrate side chains comprise 25-40% of the molecular weight of hCG. The alpha-subunit contains 2 N-linked oligosaccharides; the beta-subunit contains 2 N-linked oligosaccharides, as well as 4 O-linked oligosaccharides on the C-terminal extension. The 2 most common forms of hCG synthesized by cells are regular hCG and hyperglycosylated hCG (hCG-H). HCG-H contains more sugar residues than regular hCG: 1.5-fold more sugar residues on the N-linked oligosaccharides (16 versus 11 sugar residues for regular hCG) and 2-fold more sugar residues on O-linked oligosaccharides.
Alternate Names
Beta-HCG in blood serum - qualitative; Human chorionic gonadotrophin - serum - qualitative; Pregnancy test - blood - qualitative; Serum HCG - qualitative; HCG in blood serum - qualitative
Reference Range
Human chorionic gonadotropin (hCG) is a dimer consisting of a 145 amino acid beta-subunit that is unique to hCG and a 92 amino acid alpha-subunit. The alpha-subunit is identical to that for luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH). The alpha and beta-subunits have separate genes on separate chromosomes (chromosomes 6 and 19, respectively). After synthesis, the alpha and beta-subunits are bonded with a noncovalent bond before being released into the circulation.
Children reference range
The reference ranges for pediatric males are as follows:

  • Birth-3 months - 50 IU/L or less*
  • 3 months-18 years - 0.8 IU/L or less

The reference ranges for pediatric females are as follows:

  • Birth-3 months - 50.0 IU/L* or less
  • 3 months-18 years - 2.3 IU/L or less

*hCG, produced in the placenta, partially passes the placental barrier. Newborn serum beta hCG concentrations are approximately 1/400th of the corresponding maternal serum concentrations, resulting in neonate beta hCG levels of 10-50 IU/L at birth. Clearance half-life is approximately 2-3 days. Therefore, by 3 months of age, levels comparable to adults should be reached.
Adult reference range (97.5 percentile)

  • Males - 0.8 IU/L or less
  • Females - Premenopausal, nonpregnant: 2.3 IU/L or less. Postmenopausal: 7.3 IU/L or less.

Interpretation
Elevated levels are seen with pregnancy.
Elevated levels are seen with HCG-secreting tumors.
A rise in hCG levels above the reference range in patients with a history of an hCG-producing condition is suggestive of recurrent disease.
Indications/Applications
Gestational and nongestational trophoblasts are by far the most common sources of hCG, but a small amount of the hormone may also be produced by the pituitary gland and nontrophoblastic malignancies.
Pregnancy
The syncytiotrophoblast covers the villous tree and has several functions, such as transport of gases, nutrients, and waste products and synthesis of peptide and steroid hormones that regulate placental, fetal, and maternal systems. The syncytiotrophoblast produces regular hCG, which promotes progesterone production by the corpus luteum until placental progesterone production becomes established (after 6 weeks of gestation). Regular hCG also appears to play a role in myometrial spiral artery angiogenesis
The level of free beta-subunit of hCG is often determined in pregnant women as part of maternal serum screening for Down syndrome. The free beta-subunit variants measured depend on the assay. Increased total hCG levels in the first and second trimester are associated with Down syndrome, while decreased levels may occur in trisomy 18. Elevations of hCG can also occur in multiple pregnancies, singleton pregnancies in which the gestational age has been overestimated, triploidy, fetal loss, and hydrops fetalis.
Description: C:\Documents and Settings\Administrator\Desktop\history.jpg
Serum total hCG concentration peaks at about 93,000 mIU/mL (range 27,300-233,000 mIU/mL) at 8- 11 weeks of gestation.
Gestational trophoblastic disease
HCG promotes trophoblast growth and invasion. The invasion may be controlled, as in implantation of pregnancy and complete/partial mole, or malignant, as in the invasive gestational trophoblastic diseases, choriocarcinoma and invasive mole.
Complete and partial mole
Regular hCG is the principal form of hCG associated with complete and partial hydatidiform mole.
A total hCG result greater than 100,000 mIU/mL strongly suggests complete hydatidiform mole, although the peak hCG in many normal pregnancies can reach this level.
Partial moles produce less regular hCG than complete moles. In the USA hCG Reference Service experience, the median hCG concentration in 21 partial moles was about 49,000 mIU/mL (range 11,600-220,114 mIU/mL), and only 14% of cases exceeded 100,000 mIU/mL.

Invasive mole and choriocarcinoma
In gestational trophoblastic neoplasias, such as invasive mole and choriocarcinoma, a high level of hCG can help to distinguish invasive from noninvasive mole, although some overlap occurs in their normal ranges.
Serial measurement of hCG levels is standard follow-up of women diagnosed with complete or partial mole. An increasing or plateauing level of total hCG is diagnostic of invasive disease (invasive mole or choriocarcinoma).
Choriocarcinoma
Choriocarcinoma consists of sheets of anaplastic cytotrophoblasts and syncytiotrophoblasts without chorionic villi. Some intermediate trophoblasts may also be seen. HCG levels approaching 600,000 mIU/mL are seen. The level of hCG correlates with tumor mass.
Pituitary gland
The normal pituitary gland produces a small amount of hCG. The level of hCG attributable to pituitary production ranges from 1-32 mIU/mL.
Pituitary production of hCG is most notable around the time of menopause (natural or surgical) and prior to ovulation, which are times when LH levels peak. One possible explanation is that a small amount of hCG is produced along LH because the single LH beta-subunit gene is buried among the 7 back-to-back hCG beta-subunit genes.
Return of the serum hCG concentration to undetectable following pregnancy termination varies widely from 7-60 days. The period of time depends primarily upon the hCG concentration at the time of termination. The hCG concentration peaks at 8-11 weeks at approximately 90,000 mIU. This is in contrast with term pregnancy, for which the hCG concentration is lower. The decline in serum hCG is rapid for the first several days (half-life 9-31 hours) and then proceeds more slowly (half-life 55-64 hours).
Nongestational malignancies
Outside of pregnancy, hCG may be secreted by abnormal germ cell, placental, or embryonal tissues, in particular seminomatous and nonseminomatous testicular tumors; ovarian germ cell tumors; gestational trophoblastic disease (GTD, hydatidiform mole, and choriocarcinoma); and benign or malignant nontesticular teratomas. Rarely, other tumors including hepatic, neuroendocrine, breast, ovarian, pancreatic, cervical, and gastric cancers may secrete hCG, usually in relatively modest quantities
During pathologic hCG production, the highly coordinated secretion of alpha and beta subunits of hCG may be disturbed. In addition to secreting intact hCG, tumors may produce disproportionate quantities of free alpha subunits or, more commonly, free beta subunits. Assays that detect both intact hCG and free beta hCG, including this assay, therefore, tend to be more sensitive in detecting hCG-producing tumors.
With successful treatment of hCG-producing tumors, hCG levels should fall, with a half-life of 24-36 hours, and eventually return to within normal limits.
Considerations
An elevated HCG level may be physiologic, pathophysiologic from a tumor or artifactual from a false-positive hCG test. Unless a tumor is evident, excluding these possibilities before initiating chemotherapy for assumed persistence of disease is essential.
Description: C:\Documents and Settings\Administrator\Desktop\hcg tsh.jpg
A false-positive HCG test may be caused by naturally occurring cross-reacting antibodies that interfere with the test. The capture and tracer antibodies used for hCG testing may be goat, sheep, or rabbit polyclonal antibodies or mouse, goat, or sheep monoclonal antibodies. Humans extensively exposed to animals or certain animal byproducts can develop human antibodies against these animal antibodies (HAAA). In addition, humans naturally generate human anti-human immunoglobulin antibodies that can cross-react with and bind animal antibodies; these are called heterophilic antibodies.
Also, recent infections or exposure to mononucleosis can produce these HAAAs; those with IgA deficiency syndrome also often have heterophilic antibodies. Each human antibody is bivalent, so if an HAAA or heterophilic antibody is present in a person's serum, it can bind and link together the immobilized and tracer antibodies of the hCG test, making an immobilized capture antibody-heterophilic antibody/HAAA-tracer antibody sandwich, which results in a false positive hCG result. The false positive HCG test can lead to the misdiagnosis of cancer and sometimes lead to needless surgery and chemotherapy.
To prevent false testing, animal serum and nonspecific animal antibodies are added to HCG assays with capture antibody, tracer antibody, and other components. This excess of nonspecific antibodies overwhelming saturates heterophilic antibodies and HAAA in human serum samples and usually eliminates their interference with the assay. This method does not always work, however, and false positive cases still occur. This understandably creates confusion, as some false positive cases are incorrectly interpreted as recurrence of gestational trophoblastic disease.
Two main methods for identifying false-positive hCG tests exist are as follows:
The most readily available approach is to show the absence of hCG in the patient's urine. A true hCG elevation should be present in both serum and urine. Urine HCG is usually never detected in patients with false-positive serum hCG tests. A sensitive urine hCG test should be used to avoid missing low-level true-positive tests. Alternatively, to detect low concentrations of hCG, urine samples can be tested on the same instrument used to quantitate hCG in serum samples; these tests are typically sensitive. Avoid using a point-of-care urine test, as these tests tend to be insensitive to low levels of hCG.
A second useful way of identifying a false-positive serum hCG result is to send the serum to 2 laboratories using different commercial assays. If the assay results vary greatly or are negative in one or both alternative tests, then a false-positive hCG can be presumed.
Patients who have false-positive hCG test results are also at risk for other false positives, such as CA-125 and thyroid antibodies. They should make their future health care providers aware of this problem and it should be noted in their medical records.
Why the Test is Performed
Most often, this test is performed to determine if you are pregnant or not. The serum HCG level may also be high in women with certain types of ovarian tumors or men with testicular tumors.
Collection and Panels
Specimen type is as follows:

  • Serum

Specimen required is as follows:

  • Container/tube: Red top (preferred)
  • Acceptable: Serum gel
  • Specimen volume: 1.5 mL
  • Specimen minimum volume: 1 mL

Reject due to the following:

  • Hemolysis (mild okay; gross reject)
  • Lipemia (mild okay; gross okay)
  • Icterus (not applicable)

Specimen Stability Information


Specimen Type

Time

Temperature

Serum

7 days

Refrigerated (preferred)

Serum

180 days

Frozen

How the Test is Performed
Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.
Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
How to Prepare for the Test
No special preparation is usually necessary.
How the Test Will Feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Risks
There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:

  • Excessive bleeding
  • Fainting or feeling light-headed
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

Results
Qualitative Beta HCG:

  • A POSITIVE Beta HCG means that the woman is pregnant
  • A NEGATIVE Beta HCG means that the woman is NOT pregnant

Quantitative Beta HCG:

  • The result is given as a number, indicating the measured concentration of the hormone in the blood
  • The fetus is usually visible on a Trans-Vaginal Ultrasound scan when the level is above 1500 units
  • When the level is above 4000 units, the fetus is also usually visible on a Trans-Abdominal Ultrasound scan
  • The Beta HCG level usually doubles approximately every 2 days

Normal Results

  • The test is negative if you are not pregnant.
  • The test is positive if you are pregnant.

What Abnormal Results Mean
If your serum HCG is positive and you do not have a pregnancy properly implanted in the uterus, it may indicate:

  • Ectopic pregnancy
  • Miscarriage
  • Testicular cancer (in men)
  • Trophoblastic tumor
  • Hydatidiform mole
  • Ovarian cancer

Beta HCG levels - and how to interpret them
Successful conception is clinically confirmed by a blood test for the presence of beta HCG. It is the most sensitive, accurate and reliable of pregnancy tests.
When you finally get pregnant, the doctor will monitor the health of your pregnancy by measuring your beta HCG ( also known as beta) levels. A pregnancy should be documented as early as possible. This is important, because appropriate care and precautions can then be taken at an early stage. The most sensitive, accurate and reliable pregnancy test is a blood test for the presence of beta HCG (human chorionic gonadotropin), often just called "beta". The HCG is produced by the embryo, and is the embryo's signal to the mother that pregnancy has occurred. Beta HCG levels vary according to the gestational age. In a non-pregnant woman, they are less than 10 mIU/ml. They are typically about 100 mIU/ml 14 days after ovulation in a healthy singleton pregnancy. They should double every 48- 72 hours in a healthy pregnancy.
Description: C:\Documents and Settings\Administrator\Desktop\hcg tsh tbg.jpg
The levels are higher in a multiple pregnancy; and if the levels don't double as expected, this suggests that the pregnancy is unhealthy. Possibilities include a non-viable intrauterine pregnancy which will miscarry; or an ectopic pregnancy. If the beta HCG level is more than 1000 mIU/ml, and the doctor cannot see a pregnancy sac in the uterine cavity on vaginal ultrasound scan, then it's possible you have an ectopic pregnancy. Beta HCG levels can be measured in the blood by RIA (radioimmunoassay) , CLIA (chemiluminescent assay) and DELFIA ( fluorescent immunoassay) testing; and positive levels (more than 10 mIU/ml) in the blood can be detected as early as 2 days before the period is missed. In the old days, the only way of determining the presence of HCG was by testing the urine, i. e, by using urine pregnancy test kits. Modern urine pregnancy kits (using monoclonal antibody technology ) are now quite sensitive and can detect a pregnancy as early as 1 to 2 days after missing a period (at a blood HCG level of about 50 to 100 mIU/ml). The benefit of urine pregnancy test kits is that they are less expensive; and testing can be done at home by the patient herself. However, instructions need to be followed carefully, and errors in interpreting the test results are not uncommon. These errors could occur if the urine is too dilute; or if the test is not done properly; or if there is a urinary tract infection exists.
The major advantage of blood tests is the fact that they measure the actual level of the HCG in the blood - and this factor can be very helpful in managing pregnancy problems, if they occur. Most clinics start testing beta HCG levels about 14 - 16 days after egg collection; and repeat the test every 48-72 hours. As the embryo grows rapidly, HCG levels normally double every 2 to 3 days. Thus, one reliable sign of a healthy pregnancy is the fact that the HCG levels are increasing rapidly, and often doctors will measure serial beta HCG levels 3 days apart in order to determine the viability of the pregnancy. A rising HCG level is reassuring. Typically, in a healthy singleton pregnancy, the beta HCG level is about 100 mIU/ml about 16 days after ovulation, though this level can vary considerably. The levels are higher in multiple pregnancies; and lower in non-viable pregnancies and ectopic pregnancies.
Problems with HCG testing can occur if you have earlier been given HCG (human chorionic gonadotropin) injections for inducing ovulation. Normally, this exogenous HCG is excreted by the body in 10 days; but sometimes it can linger on. This is why, if the HCG level is very low, the test may need to be repeated, to confirm that the level is increasing. If the positive test result is because of the HCG injection, the level will decline. If you are pregnant, the HCG level should rise.
What are "biochemical pregnancies" ? These are pregnancies in which the HCG test is positive after the period has been missed; the levels increase, but are still low; and no pregnancy is ever documented on ultrasound. Biochemical pregnancies are often seen after IVF (In Vitro Fertilization) and GIFT. While they are not clinical pregnancies, they are of useful prognostic information, because they may mean that your chance of getting pregnant in a future cycle are good.
One drawback with the HCG test is that a positive HCG simply means a pregnancy is present in the body - it does not provide any information about the location of this pregnancy, which may be tubal or ectopic.
During the very early pregnancy, HCG levels are the only way of monitoring the pregnancy. HCG levels which do not increase as rapidly as they should may mean that there is a problem with the pregnancy - the embryo may miscarry because it is unhealthy; or the pregnancy could be an ectopic pregnancy. Differentiating between the two conditions is obviously important, and this is where vaginal ultrasound plays a key role.

 

 

 

References
http://healthengine.com.au/info/Beta_HCG_Test
http://www.nlm.nih.gov/medlineplus/ency/article/003509.htm
http://www.clinlabnavigator.com/human-chorionic-gonadotropin-pregnancy-test.html
http://emedicine.medscape.com/article/2089158-overview#showall
http://www.drmalpani.com/betaHCGlevels.htm
http://www.wisegeek.com/what-is-hcg.htm
http://www.wisegeek.com/what-are-beta-hcg-levels.htm
http://www.wisegeek.com/what-is-a-quantitative-blood-test.htm

Product Tags

Use spaces to separate tags. Use single quotes (') for phrases.