Human chorionic gonadotropin (hCG) is a hormone for the maternal recognition of pregnancy produced by trophoblast cells that are surrounding a growing embryo (syncytiotrophoblast initially), which eventually forms the placenta after implantation. The presence of hCG is detected in some pregnancy tests (HCG pregnancy strip tests).
What You Need to Know About hCG Levels:
- As you get further along in pregnancy and the hCG level gets higher, the time it takes to double can increase to about every 96 hours.
- Caution must be used in making too much of hCG numbers. A normal pregnancy may have low hCG levels and result in a perfectly healthy baby. The results from an ultrasound after 5 -6 weeks gestation are much more accurate than using hCG numbers.
- An hCG level of less than 5 mIU/mL is considered negative for pregnancy, and anything above 25 mIU/mL is considered positive for pregnancy.
- An hCG level between 6 and 24 mIU/mL is considered a grey area, and you’ll likely need to be retested to see if your levels rise to confirm a pregnancy.
- The hCG hormone is measured in milli-international units per milliliter (mIU/mL).
- A transvaginal ultrasound should be able to show at least a gestational sac once the hCG levels have reached between 1,000 – 2,000 mIU/mL. Because levels can differentiate so much and conception dating can be wrong, a diagnosis should not be made by ultrasound findings until the hCG level has reached at least 2,000 mIU/mL.
- A single reading is not enough information for most diagnoses. When there is a question regarding the health of the pregnancy, multiple testings of hCG done a couple of days apart give a more accurate assessment of the situation.
- The hCG levels should not be used to date a pregnancy since these numbers can vary so widely.
- There are two common types of hCG tests. A qualitative test detects if hCG is present in the blood. A quantitative test (or beta) measures the amount of hCG actually present in the blood.
Guideline to hCG levels in weeks during pregnancy
how to test HCG hormone level
1. Urine Test
The urine test kit usually uses the hormone hCG to determine the pregnancy. A positive result means you’re pregnant and a negative result means you’re not. If the test is positive, it can take several weeks for the pregnancy hormone to leave your body, so you may want to use the test again to confirm the pregnancy.
2. Blood Test
A blood test is the most accurate way to detect hCGlevels, because more of the pregnancy hormone is present in the blood than in the urine. Blood tests can detect levels between 5 and 10 mIU/mL versus the 20 mIU/mL that most at-home pregnancy tests can detect.
Low HCG Level
If your hCG levels fall below the normal range, it’s not necessarily a cause for concern. Many women have gone on to have healthy pregnancies and babies with low hCG levels. Most women don’t ever have cause to find out what their hCG levels are specifically.
However, sometimes low hCG levels can be caused by an underlying problem.
1. Gestational age miscalculated
Typically, the gestational age of your baby is calculated by the date of your last menstruation. This can be easily miscalculated, particularly if you have a history of irregular periods or are unsure of your dates.
A miscarriage is a pregnancy loss that occurs before 20 weeks of gestation. Sometimes low hCG levels can indicate that you have had or will have a miscarriage. If the pregnancy fails to develop a placenta, then the levels may be normal initially but fail to rise. Common signs that you are experiencing a miscarriage are:
- vaginal bleeding
- abdominal cramps
- passing tissue or clots
- cessation of pregnancy symptoms
- discharge of white/pink mucus
3. Blighted ovum
This is when an egg is fertilized and attaches to the wall of your womb, but does not continue to develop. When the gestational sac develops, hCG hormone can be released, but the level does not rise since the egg doesn’t develop.
This occurs very early in pregnancy. Most women won’t even know that it’s taken place. Usually you’ll experience your normal menstruation symptoms and assume it’s your usual period. However, if you’re trying to conceive, you may do an early pregnancy test that could pick up the presence of hCG.
4. Ectopic pregnancy
An ectopic pregnancy is when the fertilized egg remains in the fallopian tube and continues to develop. It’s a dangerous and life-threatening condition, as it may cause the fallopian tube to rupture and bleed excessively. Low hCG levels can help to indicate an ectopic pregnancy.