These things can really confuse us a lot! Those suspecting they might be pregnant or trying to become pregnant can get very confused when it comes to a pregnancy test. In addition to anxiety and all the anticipation, the result can come in two ways: just positive or just negative. But it can also come as a number, and that can make things even more confusing. But what exactly is HCG?

The blood tests that measure the amount of HCG are called quantitative beta tests. They show the level of the hormone and can also indicate how far along the pregnancy is1.

These quantitative tests can precisely indicate whether a pregnancy exists or if the hormone is progressing as it should. They are more reliable than the qualitative test because they can detect even minimal HCG amounts, almost to zero. For those who have undergone fertility treatment, have trouble getting pregnant, or are more anxious, this pregnancy test is effective for finding out if the pregnancy is progressing as expected. That’s because HCG doubles every 48 hours. So, if you took the quantitative beta HCG test very early, you can repeat it after the necessary time and see if it’s developing normally. The unit used to measure HCG is called mIU/ml, and it determines the hormonal amount per ml of blood. If it’s higher than a certain value, it’s considered positive.

Diagnosis of Hydatidiform Mole

Cases of hydatidiform mole can also be detected through this beta HCG test2. It shows a very high amount of hormones, far above the normal level for a pregnancy stage, as the table below shows:

3-4 weeks 9 – 130
4-5 weeks 75 – 2600
5-6 weeks 850 – 20,800
6-7 weeks 4,000 – 100,200
7-12 weeks 11,500 – 289,000
12-16 weeks 18,300 – 137,000
16-29 weeks 1,400 – 53,000

In fact, there are several tables3. They vary because each lab has its own reference for a positive and a parameter for the weeks of pregnancy. For example, Lavoisier and Delboni use above 25mIU/ml as the cutoff for positive. Others use a value above 50mIU/ml. Below that, the result is considered indeterminate and it’s suggested to repeat the test after 2 to 5 days. The variation among lab values can be confusing, but personally, I consider it positive from 25 mIU onward.

The qualitative beta HCG pregnancy test is very similar to the pharmacy pregnancy test. While the home test uses urine, the lab version uses blood serum, which is processed to detect HCG in the blood. It’s super simple and the result is available quickly; this test can be done at any local lab.

If you’re in a hurry and want same-day results, high-sensitivity pharmacy pregnancy tests are an option. An example is the Famivita pregnancy test, which is sensitive to 10 mIU and can detect HCG levels up to 5 days before your period is late.

When Should You Take a Pregnancy Test?

To avoid doubts about when to take a pregnancy test, take into account the following factors:

  • Missed period: you should go at least 2 days without your period. If you test too early, you could get a false negative result.
  • If you underwent fertility treatment with HCG-based medication, it’s advised to wait longer before taking a pregnancy test.
  • Irregular cycles: it’s best to monitor your cycle to know when you were fertile. To be more certain of this period and your ovulation, Famivita ovulation tests are a great option.

Fasting is not required for the quantitative beta test, nor for the qualitative beta. They can both be done at any time of day and are very safe, as they only use the hormone present in your body to detect pregnancy. If possible, ask for the quantitative beta HCG test. It’s more effective and just as good as the qualitative one. Hope this helps!

Frequently Asked Reader Questions!

Lately, I have received a lot of similar questions. So, I decided to answer some of the questions that always appear here. If your doubt isn’t addressed, please feel free to leave a comment to ask yours.

Can the beta HCG test give a false result?

Yes, it can, but the beta HCG test is very reliable. It can only give a false negative if you took the beta test too early. That’s why I often recommend taking the test after a safe delay of about 7 days. After fertilization, the beta HCG test can detect the hormone within 48 hours, even in very low amounts. However, the lab’s sensitivity and method can impact the result. If you still suspect pregnancy, it’s a good idea to repeat the test.

Video Explaining If Beta is Positive or Negative

Can the amount of hormone in the blood determine gestational age?

Not always, but most of the time the amount of HCG hormone in the blood can give an idea of how far along a pregnancy is. However, it is not a reliable way to confirm gestational age. Since women don’t always remember their last menstrual period, you can usually determine gestational age more accurately via ultrasound or the last menstrual period – the LMP. But as we saw in the post about late ovulation, you can’t always rely on the last period or on hormone levels alone. A woman may ovulate sooner or later than she thinks, which affects pregnancy dating.

Can the HCG Test Be Replaced With Pharmacy Tests?

It depends. Even if you’ve used some pharmacy tests, it’s much better to confirm pregnancy with a blood HCG test. This is because of hormone levels. Some pharmacy tests are as good as or even surpass laboratory sensitivity in detecting pregnancy, like Famivita pregnancy tests, but it’s always safest to have a laboratory test to be sure.

What Can a Low HCG Level in the Blood Mean?

In some cases, the hormone may be lower than needed for a positive for two reasons. Either it’s a very recent pregnancy, resulting in low hormone levels, or it could be a case of chemical pregnancy. However, before worrying or being alarmed, it’s very important to repeat the test to see if the hormone has progressed. Normally, it doubles (or almost doubles—the important thing is that it increases) every 48 hours. This way, you can track the hormone’s progression in the blood. I recommend doing the calculation here on the HCG calculator.

Should I Do the Quantitative or Qualitative Test?

Your doctor will decide which test is best, depending on your situation. The qualitative test is clear and straightforward, giving only a positive or negative result. The quantitative test shows the value and amount of hormone, which helps monitor the course of the pregnancy.

Are the Quantitative and Qualitative Tests Reliable?

Yes, all tests done via a woman’s blood draw are reliable. However, if the test is performed too early and can’t detect the minimum HCG hormone, results may differ.

Also see: Chemical Pregnancy, What Now?