Human chorionic gonadtropin, commonly referred to as HCG is a hormone that is produced that alerts the body that conception of a pregnancy has occurred. HCG is made from cells that form the placenta. The placenta will be providing nourishment to the fertilized egg after it attaches to the uterine wall.
Rising Levels of HCG
According to the American Pregnancy Association, HCG levels can be detected via a blood test approximately 11 days after conception. HCG testing by blood is referred to as quantitatively. This testing will provide the actual blood concentration of HCG. HCG levels are detectable in urine about 12-14 days from the time of conception.
When HCG is tested in urine, it is called qualitatively and the urine test only provides a positive or negative result of HCG being present. HCG levels should double every 48 hours. HCG levels will reach their highest levels in the first 8 to 11 weeks of pregnancy. HCG levels start to level off and will no longer keep climbing at the same rate the remainder of the pregnancy.
HCG values are helpful to indicate if a pregnancy has progressed enough to be visible by ultrasound in the uterus. A transvaginal ultrasound can detect and show a pregnancy once HCG levels reach 2,000. If HCG levels are over 2,000 and no fetus is visible, it is an indication that the pregnancy is located outside of the uterus and will not be viable.
The progression of HCG levels rise every 48 hours. The rate should double. The lower limit of an increase is at 66 percent within two days. If the HCG levels have not risen by the 66 percent increase in two days the pregnancy does not have a favorable outlook. If the HCG levels fall, this always is an indication of a nonviable pregnancy.
A higher level than normal of HCG can indicate that there was a miscalculation of the date of conception, a molar pregnancy or a multiple pregnancy. HCG that is detected at a higher than normal level in women who are not pregnant can be an indication of a choriocarcinoma of the uterus or ovarian cancer. HCG that is detected at a higher than normal level in men can be an indication of testicular cancer.
Certain medications can decrease HCG levels such as diuretic and promethazine. Medications that can increase HCG levels are promethazine, phenothiazine, anti-parkinsonian drugs, and anti-convulsants.