What is human chorionic gonadotropin (HCG)?
During pregnancy, cells in the growing placenta produce HCG. The placenta is like a nourishing sac for the fertilized egg, attaching it to the uterine wall.
We can find HCG in a blood sample approximately 11 days after conception. The levels of HCG keep doubling every 48 to 72 hours and reach their highest point between 8 to 11 weeks after conception.
After reaching this peak, HCG levels decrease and stabilize, staying constant for the remainder of the pregnancy.
Why is the HCG blood test done?
The HCG blood test is done to:
- Confirm if someone is pregnant.
- Estimate how long the pregnancy has been going on.
- Identify abnormal pregnancies, like ectopic pregnancies.
- Diagnose a possible miscarriage.
- Screen for Down syndrome.
This test is also used before certain medical treatments, like X-rays, to check if someone is pregnant. If the test shows a person is pregnant, healthcare providers can take steps to protect them and make sure any medical treatments won’t harm the developing baby.
How is the HCG Blood Test Done?
The HCG blood test, specifically the quantitative test measuring the HCG hormone level, involves the following steps:
- Preparation: An elastic band is wrapped around your upper arm to make veins visible and facilitate the needle insertion.
- Cleaning the Area: The healthcare professional cleans the skin around the vein with alcohol.
- Blood Collection: The needle is inserted into the vein, and a tube is attached to collect the blood.
- Elastic Band Removal: Once enough blood is collected, the elastic band is removed from your arm.
- Finishing Up: As the needle is taken out, cotton or gauze is applied to the puncture site. Pressure is added and secured with a bandage.
- Sensations: You might feel a brief stinging or pinching during needle insertion, or you may not feel anything at all. Minor discomfort or stinging might be experienced while the needle is in the vein, and there could be mild throbbing afterward.
After measuring your HCG levels, the results are sent to your doctor. They may schedule an appointment to discuss the test findings. There’s no specific preparation needed for the HCG blood test.
What do my HCG blood test results mean?
Your doctor will share your HCG levels with you after the lab test. These levels are measured in milli-international units of the HCG hormone per milliliter of blood (MIU/ML).
Here’s a simple guide to normal HCG levels during pregnancy:
| Weeks from the last menstrual period | Normal HCG levels (MIU/ML) |
| Week 4 | 0–750 MIU/ML |
| Week 5 | 200–7,000 MIU/ML |
| Week 6 | 200–32,000 MIU/ML |
| Week 7 | 3,000–160,000 MIU/ML |
| Weeks 8–12 | 32,000–210,000 MIU/ML |
| Weeks 13–16 | 9,000–210,000 MIU/ML |
| Weeks 16–29 | 1,400–53,000 MIU/ML |
| Weeks 29–41 | 940–60,000 MIU/ML |
In nonpregnant women, normal hCG levels are usually less than 10.0 MIU/ML.
If Your Levels Are Lower Than Normal, It May Indicate:
- Miscalculation of pregnancy dating
- Possible miscarriage or blighted ovum
- Ectopic pregnancy
If Your Levels Are Higher Than Normal, It May Indicate:
- Miscalculation of pregnancy dating
- Molar pregnancy (abnormal mass in the uterus)
- Multiple pregnancy (twins or triplets)
- Your doctor will help you understand what your results mean for your pregnancy.
Final Note
Stay calm if your hCG levels don’t match the “normal” range exactly. These figures are estimates, and having hCG levels lower than normal doesn’t necessarily mean an unhealthy pregnancy.
Around six weeks, you’ll have an ultrasound, which is more accurate than relying solely on hCG numbers.
If there’s a reason for concern in your pregnancy, your doctor might conduct multiple hCG readings a few days apart to get a better understanding of your situation.
Since numbers can vary, it’s crucial to trust your doctor’s guidance on your pregnancy’s health. If your doctor senses a problem, they’ll monitor your hCG levels.
If you’re worried about something, don’t hesitate to ask questions. Let your doctor know right away if you experience any problems. Open communication is key to ensuring a healthy pregnancy.