December 7, 2023
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Blood Test Health Medical PREGNANCY TEST

Why do you need a human chorionic gonadotropin (HCG) Test?

What is human chorionic gonadotropin

A human chorionic gonadotropin (HCG) test helps to determine HCG levels in the blood or urine. This test can show if you are pregnant and a person is developing an adequate amount of particular pregnancy-related hormones. An HCG level increases rapidly when you are in the first trimester, this starts falling in the second and third trimesters with the development of pregnancy. In this article, you will read when you need the HCG pregnancy test and its complete overview. 

What is human chorionic gonadotropin?

Human chorionic gonadotropin (hCG) is a hormone produced by your placenta when you become pregnant. The placenta is an organ that develops in your uterus during pregnancy. When your placenta starts developing hCG, it activates your body to make more estrogen and progesterone. With a combination of hCG, these hormones help stiffen your uterus lining and indicate your body to pause releasing eggs or menstruating. The proper and accurate levels of these three hormones help and carry the pregnancy. 

hCG is also known as the pregnancy hormone because your body contains it in excess during pregnancy. HCG levels are not only an indicator of pregnancy, but it also helps evaluate the accurate development of your pregnancy. Your healthcare provider often asks for different HCG tests or measurements to follow the progress of a pregnancy. 

How and when hCG develops in your body?

HCG is present in your urine or blood within ten to 11 days after conception, which means when a sperm fertilizes an egg. A fertilized egg moves through your fallopian tubes to the uterus (a pear-shaped organ that helps in menstrual, pregnancy, and fertility). The fertilized egg also known as an embryo attaches to your uterus wall, which activates the placenta to develop. Your placenta starts developing and discharging hCG into your blood and urine. 

Generally, hCG increases instantly in the initial eight to 10 weeks of pregnancy. After that, your hCG levels decrease with time till the birth of a child. In a few cases, certain germs or other cancers may lead to developing hCG. Your doctors observe how fast the hCG levels increase in a person in their early stage of pregnancy to find the development of pregnancy and the unborn child. 

How and when hCG develops in your body

What is the purpose of the hCG test?

An HCG test is a test that can provide information about your pregnancy. The following are the significant uses of an HCG test, including:

  • Identification of pregnancy

If the women have HCG levels greater than 5 mIU/mL, they are pregnant. The hCG levels increase within ten days of pregnancy. 

  • Miscarriage disorder

If you have consistently lower hCG levels than the recommended levels, you may have a high risk of miscarriage, which means you will not become pregnant more. 

  • Healthy development of pregnancy

There are certain weekly values listed for hCG levels during pregnancy. These levels provide a signal of healthy development of pregnancy. A doctor observes the hCG levels in the initial three months of pregnancy. 

What is the purpose of the hCG test

  • Ectopic pregnancy

An ectopic pregnancy occurs when the fetus is within the fallopian tube instead of the uterus. The development of hCG occurs in the fallopian tube combined with the uterus. Therefore, the hCG levels influence ectopic pregnancy. 

  • Occurrences of multiple pregnancies

Persistently increased hCG levels can give signals for multiple pregnancies. An ultrasound is the imaging exam that helps to check it. A sudden increase in the HCG levels because your body takes time to increase the development of the substance in multiple pregnancies. 

  • Age of the fetus

Measuring the hCG levels can potentially tell the fetus’s age. The pregnant woman’s body creates more hCG with the growth of the fetus. It can also be due to multiple pregnancies (twins, triplets, etc.)

Types of HCG tests

The amount of HCG can be identifiable in your blood or urine. Due to the detection ability of low hCG, a blood test is more suitable and accurate for diagnosis. Two types of HCG tests help measure hCG levels, including

Qualitative HCG tests

The qualitative HCG test helps see high HCG levels in the blood or urine. A high HCG amount shows that the woman is pregnant, whereas a negative qualitative HCG test tells that a woman is not pregnant. A doctor may recommend repeating the test after certain days if they still think about your pregnancy. 

Quantitative HCG tests

Quantitative HCG tests

This test is also known as a beta HCG test. A blood test that helps determine the amount of specific HCG hormone in your blood. Generally, the measurement of HCG hormone is in international units per liter (IU/L). The quantity of HCG you possess helps evaluate the age of the fetus.  

You will have high HCG levels in the first trimester (initial three months of pregnancy) and then it decreases with time. They are at their peak position when they reach 28,000 to 210,000 IU/L within 12 weeks after conception (when a man’s sperm fertilizes the woman’s egg). 

If you experience higher HCG than the average pregnancy level, you might have more than one fetus. 

Schedule an HCG test online to check whether or not you are in the phase of pregnancy. 

When do you need an HCG test?

For a home pregnancy test, a woman can consider taking it within one to two weeks after a missed period to receive accurate results. 

It may take many days for HCG levels to increase for the HCG test to see the hormone. If you take the pregnancy test earlier than the actual time, it would be trouble to find the hCG hormone. 

An HCG blood test can check for pregnancy at least 10 days after conception. The urine tests usually take two or additional weeks. However, few home pregnancy tests can give the results earlier than the missed period and the test results may be considered more accurate after the initial days of the missed period. 

Factors that affect HCG test results

Here are the factors that may develop false or inaccurate negative results in urine HCG tests besides taking the test on time, including:

  • Getting extra water to dilute the urine
  • Taking very high or very low amounts of urine on the test strip
  • Conducting urine tests at the end of the day 

False positive or negative results may develop if the tests have passed their expiry date. In some cases, a person may have abnormally high HCG levels, although they are not pregnant.

The following are the common causes of this, including

  • Taking particular fertility medicines
  • Pregnancy loss in the recent past
  • Molar pregnancy (A pregnancy that occurs due to a disorder in the fertilized egg)

These are the less common causes include:

  • The unexpected development of antibodies in the blood
  • Cancer, such as tumors 
  • Endocrine problems, specifically pituitary gland disorders

HCG Test result

Normal hCG levels by week

This table indicates that the hCG levels increase with time continuously in the first trimester of pregnancy before decreasing:

Weeks since the last menstrual period hCG levels (mIU/mL)
3 weeks 5 – 50 
4 weeks 5 – 426 
5 weeks 18 – 7,340 
6 weeks 1,080 – 56,500
7- 8 weeks 7,650 – 229,000
9 – 12 weeks 25,700 – 288,000
13 – 16 weeks 13,300 – 254,000
17 – 24 weeks 4,060 – 165,400
25 – 40 weeks 3,640 – 117,000
Non pregnant 6,547 – 23,808

These values can be taken as a reference only. The hCG levels can increase in various ways. A healthcare provider will determine when you require to see your hCG levels and the test results indicate your pregnancy. Many healthy pregnancies may have decreased values than the hCG levels. You can consult a healthcare provider online to discuss your hCG levels. 

What are the risks involved in the HCG test?

HCG tests generally have low risks and are considered to be very safe. When you take an HCG blood test, a healthcare provider injects a small needle into a vein of your arm to collect a small amount of blood. The blood test may develop these low risks, including bleeding, multiple bruising, and infection from the puncture site. You may also experience light-headedness or pain during needle injection. 

Urine HCG tests are risk-free and may develop false-negative results, specifically in the early stage of pregnancy. It can be stressful and dismounting to people, leading to difficulty during pregnancy. Generally, blood tests give accurate results, although these may also not catch low hCG levels in the initial stage of pregnancy. 

You may also experience an early positive result. Some people may receive positive test results in the beginning stage of pregnancy and a pregnancy loss occurs after a few days. 

If people do not take an early HCG test, they do not think about being pregnant. 

Low hCG levels 

A low hCG level may indicate the following conditions, such as:

  • Miscarriage
  • Ectopic pregnancy
  • Misjudgment of the last menstrual cycle
  • Blighted ovum (when a fertilized egg goes into the uterus lining but does not grow into an embryo)

If you experience low hCG levels during pregnancy, a healthcare provider will consider repeating the test to check your hCG levels within two or three days. They also conduct an ultrasound to observe deeply into your uterus. 

High hCG levels

High hCG levels can show up in these conditions, including:

  • Multiple pregnancies (twins, triplets, etc.)
  • Misjudgment of the last menstrual period
  • Molar pregnancy
  • Uterus abnormal growth

When do I need to consult a doctor?

People do not think about or know your hCG levels several times until you take the home pregnancy test. A healthcare provider may show that you have low hCG levels depending on the age of your pregnancy. Professional obstetricians usually check hCG levels in the initial stage of pregnancy and do not look at them until the presence of particular symptoms or problems. A healthcare provider will check for the development of pregnancy and hCG levels and conduct other imaging tests such as ultrasound. 

Why is hCG used for fertility?

HCG injections can increase the possible change in developing pregnancy if utilized with IVF (in-vitro fertilization) or IUI (intrauterine insemination). It operates by activating ovulation. 

When you experience infertility (losing the ability to become pregnant) or have a medical history of it, observing hCG levels in the initial stage of the pregnancy may provide information to your providers about the development of pregnancy. 

Taking particular fertility medicines


People know about pregnancy through a home HCG pregnancy, while an HCG blood test shows the healthy development of pregnancy. The test is usually accurate as the pregnancy continues. A single HCG pregnancy test does not give information about ectopic pregnancies, molar pregnancies, or other pregnancy consequences. Healthcare providers require additional information to detect these pregnancy problems and may ask to repeat the test to see the flow of HCG levels. Though high or low HCG levels may show a pregnancy problem, it is not always necessary. You can talk with a healthcare provider online if you have issues about the pregnancy or the development of the embryo.

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