What is Beta HCG? Its Role in Pregnancy & Normal Beta HCG Levels
Pregnancy is an exciting, yet nerve-wrecking time in your life. Upon discovering your pregnancy, your OBGYN may ask for you to have your beta hCG levels taken via bloodwork. Beta levels rise throughout pregnancy and indicate the viability of a pregnancy.
Learning your beta levels can be scary! You go to the hospital and have a vial of blood taken. In a few hours or days, the doctor’s office calls you to tell you the results. Beta levels need to be rechecked in 48 to 72 hours to make sure they are rising. Now, you have your results, but what does all of this mean? Let’s take a look at what hCG is and what your levels mean.
What is HCG?
HCG stands for human chorionic gonadotropin, but everyone refers to it as hCG because no one can say that too fast. HCG is a hormone your body creates during pregnancy. Cells inside of the placenta form hCG, which helps the egg after fertilization and implantation.
HCG isn’t a hormone typically detectable in your body unless you are pregnant. During ovulation, your egg is ready for fertilization. Sperm fertilizes the egg, and the fertilized egg makes its way down the fallopian tubes. This process can take four to six days, despite the short length of your tubes.
After the journey, the fertilized egg arrives in your uterus, where it will implant into the walls of your uterus. It is at this time that your body starts to create HCG.
Why is HCG Important?
First, hCG is important because it is what lets you know that you are pregnant! Levels of hCG can be detected by blood typically 11 days after conception. On average, it takes 12 to 14 days after conception to determine pregnancy via a urine test. When you purchase a pregnancy test at the store, it is looking for hCG in your urine. No hCG means no positive results.
Second, a healthy pregnancy isn’t possible without hCG. This hormone maintains the pregnancy and encourages the development of the fetus. It will continue to rise until the placenta fully takes over the maintenance of the pregnancy.
Doctors also believe that hCG is responsible for nausea because it stimulates the area of the brain that triggers nausea. When hCG levels start to taper off around 12 to 16 weeks, most women notice their nausea starts to reduce. Other hormones may play a role in morning sickness as well.
Understanding the Levels of HCG
In most pregnancies, hCG levels double every 48 to 72 hours. Your levels will peak between eight and 11 weeks of pregnancy. After then, the levels start to decline and level off for the rest of your pregnancy.
There is a wide range of what is considered a normal, healthy hCG level. HCG is measured in milli-international units per milliliter (mIU/mL). A level of less than five mIU/mL is a negative result, and above 25 mIU/mL is positive. Levels between 6 and 24 mIU/mL typically require a doctor to retest to confirm a pregnancy.
Let’s take a look at the potential hCG levels in weeks from your last monthly period.
- 3 weeks: 5 – 50 mIU/mL
- 4 weeks: 5 – 426 mIU/mL
- 5 weeks: 18 – 7,340 mIU/mL
- 6 weeks: 1,080 – 56,500 mIU/mL
- 7 to 8 weeks: 7,650 – 229,000 mIU/mL
- 9 to 12 weeks: 25,700 – 288,000 mIU/mL
- 13 to 16 weeks: 13,300 – 254,000 mIU/mL
- 17 to 24 weeks: 4,060 – 165,400 mIU/mL
- 25 to 40 weeks: 3,640 – 117,000 mIU/mL
Why Does Doubling Time Matter?
Learning your hCG levels doesn’t indicate a healthy pregnancy. Conception will lead to the development of the hormone. The rate at which your levels are increasing determines whether your pregnancy is healthy or not.
Your doctor will want to see the levels doubled every 48 to 72 hours. That means your blood needs checked again within two to three days. As you get further along in the pregnancy, it may take 96 hours for the levels to double.
If your levels seem low, don’t worry just yet! You could have miscalculated your pregnancy, resulting in a lower number. However, low hCG levels also mean a possible miscarriage or an ectopic pregnancy. Many doctors consider a 48-hour increase of 35% to be normal!
If your levels seem rather high, you also could have miscalculated your dates, but it also could mean twins or a molar pregnancy! Yes, your doctor might be able to determine if you are having two or more babies because the levels of hormones will be higher. There will be two or more placentas creating hCG.
What Else Should You Know about HCG Levels?
Women shouldn’t obsess too much about the hCG numbers. Your pregnancy can be healthy and have a low hCG level. Pregnant women want to know everything they can; that is normal! So, here are some more facts and things to know about hCG.
- A transvaginal ultrasound should be able to show a gestational sac once the hCG levels are between 1,000 and 2,000 mIU/mL. Most doctors prefer to wait until bloodwork shows at least 2,000 before ordering an ultrasound.
- Ultrasound is more accurate for dating a pregnancy than your levels. The numbers vary so widely, so the results could be grossly inaccurate.
- Levels of 7,200 mIU/mL mean that a yolk sac should be visible. Levels greater than 10,800 mIU/mL mean an embryo with a heartbeat should be visible.
- There are two types of hCG tests. A quantitative hCG test checks the amount of hCG in your blood. A qualitative hCG test determines if there is any hormone present in your blood.
If you do experience a miscarriage, it may take four to six weeks for your hCG levels to return to normal. The time it takes depends on how far along the pregnancy was and how the loss occurred, such as a natural loss or a D&C.
Don’t Stress Over Beta HCG Levels
If your doctor orders a series of beta hCG tests, don’t stress. It is standard for many OBGYNs to order them; he doesn’t suspect something is wrong just yet. Remember that the initial level doesn’t mean your pregnancy is healthy or not. Wait for your next test or two to determine if the levels are doubling appropriately. That will let you know if you should expect a loss.