Ever wondered what makes those lines in the pregnancy test kit go “red.” What makes the two red lines appear?
Human chorionic gonadotropin, also called hCG, is a hormone that tells you about your pregnancy. When you get pregnant, these hCG levels rise, and this rise results in the two red lines in your pregnancy kit.
Normal hCG levels in a healthy man are about 2 mIU/ml and 5 mIU/ml in a non-pregnant healthy woman.
Rising levels can be first detected in about 12-14 days after conception by a urine test. In pregnancy, the hCG levels double every 72 hours. It reaches maximum level within 8-11 weeks, and then after the decline, it reaches a stable stage and remains throughout the pregnancy. A physician takes an hCG blood test to identify if you are pregnant. The hCG amount is expressed in milli-International Units (IU/ml) of hCG per millilitre of blood.
Why is the hCG blood conducted?
Doctors conduct this test to:
- confirm a pregnancy
- to identify the approx. age of the fetus
- to diagnose an abnormal pregnancy, for example, an ectopic pregnancy
- diagnose a potential miscarriage
- for screening Down Syndrome
An hCG blood test is conducted in the pregnant woman before they undergo any special medical treatments which can potentially pose a threat to the fetus or the baby, for instance, the X-rays
Another reason to perform this test is to determine the reasons behind the rise in hCG levels, if not pregnancy.
hCG test types
There are two types of hCG tests – hCG urine test and hCG blood test.
How is an hCG Test conducted?
This test is performed by drawing blood from a vein through a procedure called venipuncture.
How would a Normal result be for a pregnant woman vs. a non-pregnant woman with healthy hCG levels?
A healthy non-pregnant woman – 5mIU/mL
After conceiving, the hCG level increases rapidly during the first trimester and then declines slowly. The normal HCG level ranges in pregnant women based on the length of the pregnancy are –
- 3 weeks LMP: 5 to 50 mIU/ml
- 4 weeks LMP: 5 to 426 mIU/ml
- 5 weeks LMP: 18 to 7340 mIU/ml
- 6 weeks LMP: 1080 to 56500 mIU/ml
- 7 weeks – 8 weeks LMP: 7,650 to 229,000 mIU/ml
- 9 weeks – 12 weeks LMP: 25,700 – 288,000 mIU/ml
- 13 weeks – 16 weeks LMP: – 13,300 – 254,000 mIU/ml
- 17 weeks – 24 weeks LMP: 4060 – 165,400 mIU/ml
- 25 weeks – 40 weeks LMP: 3640 – 11700 mIU/ml
These figures are displayed based on the length of the pregnancy dated from the last menstrual cycle/period. A woman experiencing irregular cycles might see variations in these ranges.
What do low hCG levels mean in pregnancy?
Low hCG levels in pregnancy may mean:
- Miscalculations in the pregnancy dating
- Possible miscarriages
- Ectopic pregnancy
- Blighted ovum
A low hCG needs to be rechecked within 48-72 hours to check the changing levels.
What do high hCG levels mean in pregnancy?
Similar to low levels, high levels also require constant monitoring, as high levels of hCG mean.
- Multiple pregnancies
- Miscalculations in the pregnancy dating
- Molar pregnancy
Therefore, hCG levels need to be rechecked every 48-72 hours in elevated hCG readings.
Do you need to check hCG levels regularly?
Generally, your doctor routinely monitors your hCG levels. Still, if your doctor senses some issue or in case of any abnormality such as severe cramping, bleeding, or if you have had a previous miscarriage, you may be to recheck the levels.
Can you still have a healthy pregnancy with low hCG levels?
The hCG levels differ from woman to woman, so that the numbers will differ too. Having low hCG values doesn’t necessarily mean a problematic pregnancy. What’s more important is the fact that the levels are rising overall. The levels of hCG should go upward, though, and they should decline. Any decline is an indication of abnormality.
But if your numbers are low but are increasing steadily, you don’t need to worry as the levels are at a healthy place according to you, your body, and your baby. Every female body is different, so, normally, numbers will differ.
What interferes with the levels of hCG in the body?
A positive pregnancy result generally means pregnancy, but sometimes it can happen that you later find out you’re not pregnant; although this is rare, it is certainly possible. This might be due to some of the reasons given below:
- Any medication containing hCG. This can affect the levels of hCG in the body and result in a false positive. Medications used in infertility treatments affect your hCG levels. While availing of such treatments, ask your doctor to help you understand how hCG levels may affect a test. Contraception or any hormone medications do not generally affect the hCG test.
- Type of cancer
- Possible miscarriage
In the context of False-negative results, there are two types of false-negative results
A false positive and a false negative result. Both are due to differences in the levels of hCG.
A false negative
A negative test means non-pregnancy, and a false negative test is where you are indeed pregnant, but the test came out negative. A test can result in a negative if it has been taken too early in the pregnancy. Too early that your body didn’t yet get time to produce the required levels of hCG.
Therefore, retake an hCG test within 48 to 72 hours to observe any changes in hCG levels due to such circumstances.
A positive result is where a woman is pregnant, and the false positive means non-pregnancy.
If there’s a false-positive test result, the test indicates that a woman is pregnant, when in fact, she isn’t. This is possible if your body produces certain types of antibodies that contain the fragments of hCG molecules, certain medications, or errors in testing in the lab.
You can try different methods to confirm and also repeat the hCG test in 48-72 hours.
Can you increase hCG levels?
You may want to increase your hCG levels by trying some foods or remedies, but there is little to no truth that these work. Sadly, these ways cannot increase the hCG levels. Getting hCG levels won’t raise or reduce the won’t affect your chances of pregnancy as it only reflects your pregnancy health chart. Even in pregnancy, the levels rise and fall on their own. As long as your hCG levels are rising after conceiving, you are good to go.
Some facts on hCG
- hCG levels less than 5mIU/ml is considered negative for pregnancy
- hCG levels above 25mIU/ml are considered positive for pregnancy.
- When the hCG levels are within 6mIU/ml – 24mIU/ml it is considered a grey area, which means a retest is necessary to check rises in levels to confirm pregnancy.
- Further, the hCG levels rise significantly and double overtime in about every 96 hours into the pregnancy.
- Low hCG levels don’t necessarily mean complications. Even with low levels of hCG, you can have a healthy pregnancy.
- The result of a 5-6 weeks’ gestation is more accurate than hCG numbers.
- There are two types of hCG tests. A qualitative test detects hCG present in the blood, and the quantitative test (or beta) detects hCG levels in the blood.
- A single reading is not enough to diagnose the pregnancy; therefore, doctors conduct multiple tests to get an accurate assessment every couple of days.
- As the hCG levels reach 1000-2000mIU/ml, transvaginal ultrasound should be able to show you a gestational sac. As hCG levels can differ, dating pregnancy can be wrong; therefore, an ultrasound-based diagnosis is not viable until the hCG levels reach 2000mIU/ml.
Too many questions and worries about what to do?
The best solution is to speak with a health care specialist/doctor and get all answers and detach worry. Again it is perfectly normal for the number of hCG to not match as the figures are estimates. You can have a great pregnancy even with low hCG figures. Around 6 weeks, you receive an ultrasound which will be more accurate and tell more about your pregnancy.
You can also take a retest for hCG levels within a days’ gap. So don’t be concerned and talk to your doctor and understand what they are saying and follow.
Your doctor worked hard for that degree so show them trust. If you still have doubts, you can refer to multiple doctors and match what they say. But either way, “Doctors know best” when it comes to pregnancy.
So, ask them about any query or any problem you may be experiencing.
Antara Chowdhury is a Content Marketer and Strategist with 6 years of experience. She is Master degree holder in Journalism and wants to explore everything she can write on.