Human chorionic gonadotropin, also known as HCG, is a hormone usually associated with pregnancy. A urine test can detect the presence of HCG, and a blood test measures the amount of HCG in the blood. This hormone is generated by the same cells that will form a placenta to nurture the fetus after it has been implanted as a fertilized egg. In the majority of normal pregnancies, the levels of HCG double every 48 to 72 hours. There are, however, other possible causes for HCG in the urine.
Medications
According to Medline Plus, certain types of drugs can lead to the detection of HCG in the urine. These include anticonvulsant medications, drugs for Parkinson's disease, phenothiazine and promethazine. Phenothiazine is a tranquilizing medication and anti-psychotic drug, and promethazine is used to treat allergic reactions. The fertility drugs pregnyl and ovadrel are also likely to lead to the detection of HCG in urine, since these drugs are actually forms of HCG. If you are taking any of these medications, you should be aware that they may lead to the detection of HCG in your urine.
Molar Pregnancy
Another possible reason for the presence of HCG in the urine is a molar pregnancy, according to the American Pregnancy Association. A molar pregnancy is the result of sperm fertilizing an empty egg, causing abnormal tissue to grow inside the uterus. The body forms placental parts or a placenta, but there is usually no fetus, the association says. Because the body responds to this abnormality as though it is a pregnancy, molar pregnancies are often associated with increased HCG levels. Molar pregnancies are rare, occurring in one out of 1,000 pregnancies.
Choriocarcinoma
Choriocarcinoma is a type of cancer that is associated with persistently high levels of HCG, reports Medline Plus. This type of cancer, which is rare and frequently curable, may occur after a pregnancy, an abortion, or a molar pregnancy. It may also occur after an ectopic pregnancy or a genital tumor. In cases where choriocarcinoma follows a molar pregnancy, the abnormal tissue masses may continue to grow and become cancerous even after the molar pregnancy has been removed. In cases of choriocarcinoma, your pregnancy test will be positive even if you are not pregnant.
Chemical Pregnancy
A chemical pregnancy occurs when an egg has been fertilized and implanted in the uterus, but then ceases to develop, reports BabyCenter. In these cases, the fertilized egg may begin to grow enough to generate HCG and then cease to grow. This can cause a positive pregnancy test, although you will subsequently have a full menstrual period. This period may be a few days later and heavier than usual. BabyCenter reports that before home pregnancy tests became more sensitive, chemical pregnancies often went undetected.
