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hCG Doubling Time: Understanding hCG Levels in Pregnancy

hCG Doubling Time: Understanding hCG Levels in Early Pregnancy

The primary function of a pregnancy test is to look at the Human Chorionic Gonadotropin hormone (hCG levels).

What does hCG do? Why is it essential for the baby’s development? And what is the meaning of hCG doubling time for your pregnancy?

We will share with you answers to the above questions in this article. Below is all you need to know about hCG, its role in pregnancy, and how fast it rises if you’re pregnant.


The role of hCG levels in pregnancy

The Human Chorionic Gonadotropin hormone is a hormone produced throughout pregnancy and is crucial in the first trimester.

It is produced by the syncytiotrophoblastic cells of a growing placenta. The primary role of hCG is to assist the corpus luteum in increasing progesterone production, which is essential for early embryo development. More specifically, progesterone production helps support the growth of the uterine lining while preventing contractions that prevent the growth of the uterine lining in the uterus. These critical processes are necessary during early pregnancy and would not be possible without hCG production.

One of the primary ways of knowing if you are pregnant or not is by testing hCG in urine or blood. If you are pregnant, doctors will monitor your hCG levels to determine your fetus’s health.

What is hCG doubling?

After successfully implantation an egg onto the uterus, the developing placenta starts releasing hCG. As a result, hCG in healthy pregnancies doubles every 48 to 72 hours.

Read on to know some of the most frequently asked questions about hCG levels and hCG doubling in pregnancy.

How fast does hCG rise?

hCG increases/rises rapidly once you’re pregnant. Typically, doubling of hCG occurs every two days during the first four weeks of pregnancy.

How often does hCG levels double?

HCG levels double after every few days for the first four to six weeks after becoming pregnant. After that, it doubles after three to four days until the sixth week. Then, around week ten, it peaks again before levelling off and remains constant for the rest of the pregnancy.

How much do hCG levels increase daily?

hCG could rise by about 30 to 50% daily if it doubles after every two days. 

What do unusually high hCG levels mean?

Suppose your hCG levels are doubling faster than average or are exceptionally high. It could potentially be an indication of a molar pregnancy, multiple pregnancies, or down syndrome. Alternatively, you may have miscalculated on your date of conception and be further along in your pregnancy than you initially thought.

If that is the case, arrange for an appointment with your doctor to evaluate the health of your pregnancy. They will give you appropriate suggestions and the necessary steps to take for your situation.

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What do low hCG levels mean?

If you realize that your hCG levels are low (not doubling at the recommended pace), it could be a sign of a miscarriage or an ectopic pregnancy. Also, it may mean that you may have potentially miscalculated the date of your conception, and your pregnancy is further along than you initially thought.

Again, the right thing to do if you find yourself in this situation is to consult your doctor. They will evaluate your symptoms and run further tests to ease your concerns.

How often should I check my hCG levels?

The pregnancy risk level, medical history, and individual situation determine how often one checks their hCG levels.

For most pregnancies, your doctor doesn’t need to look at your hCG levels regularly. However, if you have concerning symptoms such as pain or bleeding, your doctor may need to double-check the levels to ensure they are normal for the stage you’re at in your pregnancy.

Also, your doctor may have to monitor your hCG frequently and perform a regular ultrasound if you have a history of miscarriage.

Normal hCG levels in pregnancy

It is essential to know that hCG levels change depending on the stage of pregnancy a person is in. Therefore, even though everyone’s pregnancy is different, here is a guideline of how hCG levels should be before, during, and after pregnancy.

hCG levels before pregnancy

hCG hormone is commonly associated with pregnancy, but it is also detectable in the colon, liver, and pituitary gland in small concentrations before you conceive.

Average hCG levels: Less than ten mIU in non-pregnant women. 10 to 25 mIU for a ‘borderline’ pregnancy result. More than 25 mIU for a positive result.

hCG levels during pregnancy 

A pregnant woman’s hCG levels are significantly higher than that of an average person. According to the American Pregnancy Association, the following are ranges where hCG typically lies throughout pregnancy.

  • Week 3: 5-50 mIU/ml
  • Week 4: 5-426 mIU/ml
  • Week 5: 18-7,340 mIU/ml
  • Week 6: 1,080-56,500 mIU/ml
  • Weeks 7-8: 7,650-229,000 mIU/ml
  • Weeks 9-12: 25,700-288,000 mIU/ml
  • Weeks 13-16: 13,300-254,000 mIU/ml
  • Weeks 17-24: 4,060-165,400 mIU/ml
  • Weeks 25-40: 3,640-117,000 mIU/ml

hCG levels After pregnancy

After a miscarriage, pregnancy termination, or delivery, the human chorionic gonadotropin hCG reduces with a half-life of 24 to 36 hours until the normal pre-pregnancy are met.

Can home pregnancy test detect low hCG levels?
Can home pregnancy tests detect low hCG?

hCG levels testing

The right time to test for hCG and potential pregnancy is around 11 days after your conception date. However, it may be early to get a result, and you may need to visit your doctor and provide a blood sample. But your hCG levels can be detected using a home pregnancy test if you take the test 7 to 14 days after your estimated date of conception.

There are two types of tests that you can take for hCG testing: a quantitative test and/or a qualitative test.


A qualitative test is designed to test hCG’s presence in your body. You can take a home urine pregnancy test or visit your doctor’s office to provide a blood sample.

Qualitative tests detect if your levels are above the recommended threshold, usually over 10 -20 mIU/ml. If the levels are above this threshold, you will receive a ”positive” result, and if not, you will get a ”negative” result.

A qualitative test won’t provide a specific numerical value of your hCG levels but is a reliable way of finding out if you are pregnant or not. Therefore, if you want to monitor your hCG levels closely, you will have to take a quantitative test.


A quantitative hCG test, also referred to as beta hCG test, is used to measure hCG in your blood. Unlike qualitative tests, quantitative tests can provide a numerical result to monitor and track the hCG levels in your blood over time.

This method is mostly used on women who have previously experienced miscarriages or those considered high risk. Doctors regularly monitor hCG to ensure a healthy pregnancy and offer further treatment when necessary.

hCG levels: Summary

The best way to know if your pregnancy is progressing normally is by checking hCG until about 6 or 7 weeks after your last period. After five to six weeks, ultrasound is the best tool to get information on the progress of your pregnancy. Slow rising hCG could be a symptom of ectopic pregnancy or a sign of a miscarriage, but this is not always the case. Your hCG levels alone are not enough to provide such a diagnosis. Your doctor will consider any other signs and symptoms you’re experiencing, such as backache, abdominal cramping, vaginal bleeding, evaluate the viability, and run additional tests to provide accurate information and diagnosis.