hCG Doubling Time: What to Expect Before, During, and After Pregnancy
When you take a pregnancy test, that test is looking for one thing: hCG (the Human Chorionic Gonadotropic hormone).
But what does this hormone actually do? Why is it so important for the development of your baby? And what could your hCG doubling time mean for your pregnancy?
In this article, we’re going to give you some answers to these questions! Here is everything you need to know about hCG, the role it plays in pregnancy, and how fast you can expect it to rise if you are pregnant.
The role of hCG in pregnancy
The Human Chorionic Gonadotropic hormone – also known as “hCG” and often called “the pregnancy hormone” – is a hormone that is produced throughout pregnancy and is especially critical in the first trimester.
Produced by syncytiotrophoblastic cells of the growing placenta, hCG’s main role is to help the corpus luteum ramp up progesterone production, which is vital to early embryo development. More specifically, progesterone helps to support uterine lining growth, while also preventing contractions that could inhibit growth of the uterus and uterine lining. Without the production of hCG, these critical processes necessary for early pregnancy would not be possible.
Testing for the presence of hCG in urine or blood is one of the primary ways of determining whether or not you are pregnant. If you are pregnant, doctors may also continue to monitor your hCG levels in order to assess the health of your pregnancy.
What is hCG doubling?
Once your fertilized egg has successfully implanted itself onto the uterus, your developing placenta begins to release hCG. In healthy pregnancies, hCG levels should double approximately every 48 to 72 hours.
Here is a quick look at some of the most commonly asked questions about hCG doubling and hCG levels in pregnancy.
How fast does hCG rise?
After you become pregnant, your hCG levels rise rapidly, typically doubling every two days for at least the first four weeks of pregnancy.
How often does hCG double?
During the first four to six weeks of pregnancy, hCG levels double every two days. After that, it may take three to four days to double until the sixth week. HCG then tends to peak around week ten, before leveling off and remaining constant for the remainder of the pregnancy.
How much do hCG levels increase daily?
If your hCG levels double every two days, that means that hCG could rise by approximately 30-50% daily.
What do unusually high hCG levels mean?
If you notice that your hCG levels are extremely high or doubling at a faster rate than normal, this could potentially be a sign of a multiple pregnancy, molar pregnancy, or down syndrome. Alternatively, you also may have miscalculated your conception date and are potentially further along in your pregnancy than you had previously thought.
The best thing to do in this situation is to visit with your doctor and they can evaluate the health of your pregnancy and suggest the appropriate next steps for your situation.
What do unusually low hCG levels mean?
If you notice that your hCG levels are low but doubling (or not doubling at the right pace), this could be a sign of an ectopic pregnancy or a miscarriage. However, it could also be a sign that you may have miscalculated your conception date and are not as far along in your pregnancy as you thought.
Again, the best thing to do in this situation is to speak with your doctor. They will be able to run further tests, evaluate any other symptoms you may be experiencing, and ease your concerns.
How often should I check my hCG levels?
How often you choose to check your hCG levels will depend on your individual situation, medical history, and pregnancy risk level.
For the majority of pregnancies, it is not necessary or common for your doctor to check your hCG levels on a regular basis. However, if you are in pain, bleeding, or experiencing any other concerning symptoms, your doctor may want to double-check that your hCG levels are normal for where you’re at in your pregnancy.
If you and/or your family have a history of miscarriage, your doctor may also want to monitor your hCG levels more frequently alongside regular ultrasounds.
Normal hCG levels in pregnancy
Your hCG levels will change depending on what stage of pregnancy you are in. And while everyone’s pregnancy is different, here is a rough guideline of where you can expect your hCG levels to be before, during and after pregnancy.
Even though hCG is most commonly associated with pregnancy, it can also be detected in the pituitary gland, liver, and colon before you’re pregnant – but only in small concentrations.
A “normal” hCG level for a non-pregnant individual is typically less than 5 mIU/ml.
If you are pregnant, your hCG levels will be significantly higher than the average person. According to The American Pregnancy Association, hCG levels typically lie within the following ranges 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
After delivery, miscarriage, or pregnancy termination, human chorionic gonadotropin (hCG) falls with a half-life of 24 to 36 hours until prepregnancy levels are reached.
Testing for hCG and potential pregnancy can begin around 11 days after your date of conception. However, to get a result this early, you will have to visit your doctor’s office and give a blood sample. If you can wait until 12-14 days after your estimated conception date, your hCG levels will be able to be detected by a simple at-home urine test.
When it comes to hCG testing, there are two different types of tests that you can take: a quantitative test or a qualitative test.
The purpose of a qualitative hCG test is to test for the presence of the hCG hormone in your body. You can test for this by giving a blood sample at the doctor’s office, or by taking a urine pregnancy test at home.
Qualitative tests are designed to detect whether or not your hCG levels are above a certain threshold – typically over 5-20 MIU/ml. If they are, then you will receive a “positive” result. If not, your result will be “negative”.
While qualitative tests are useful for confirming whether or not you are pregnant, they are unable to give you a specific numeric value of your hCG level. Therefore, if you need to closely monitor your hCG levels, you will need to take a quantitative test.
A quantitative hCG test, also known as a “beta hCG test” is a type of test that measures hCG in your blood. Unlike qualitative tests, quantitative tests can give you a numerical result so that you can track and monitor the amount of hCG in your blood over time.
This method of testing is particularly beneficial for women who are considered high risk or may have experienced miscarriages in the past. By regularly monitoring hCG, doctors can keep a close eye on the health of the pregnancy and provide further treatment when necessary.
✔️ Medically Reviewed by Katerina Shkodzik, M.D., OB-GYN
Dr. Katerina Shkodzik is a certified OB-GYN with a special focus on reproductive endocrinology and infertility issues. She has been practising since 2015.
Dr. Shkodzik completed her residency program in the Department of OB/GYN at the Belarusian State Medical University and fellowship program in the Department of Gynecological Surgery at the Medical University of Bialystok, Poland.
Dr. Shkodzik is extensively involved in digital health projects providing her medical expertise and integrating of cutting edge technologies in medical science and clinical practice since 2018.
Dr. Shkodzik has participated in several studies focused on PCOS, endometriosis, menstrual cycle characteristics and their abnormalities based on big data of digital health in collaboration with leading universities.
She believes that paying special attention to women's health is a crucial step to improving the world we live in.