QuestionI am trying to find answers about HCG and pregnany. Is it possible to be pregnant and have no signs of levels of HCG? Is there any reasons why the hormones will not be detected if your pregnant?
AnswerDear Maryanne,
The hormone human chorionic gonadotropin (better known as hCG) is produced during pregnancy. It is made by cells that form the placenta, which nourishes the egg after it has been fertilized and becomes attached to the uterine wall. Levels can first be detected by a blood test about 11 days after conception and about 12-14 days after conception by a urine test. Typically, the hCG levels will double every 48-72 hours. The level will reach its peak in the first trimester of pregnancy and then will decline and level off for the remainder of the pregnancy.
A transvaginal ultrasound should be able to show at least a gestational sac once the hCG levels have reached between 1000-2000 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 2000. Pregnancy tests performed too early in the pregnancy, before there is a significant hCG level, may give false-negative results. Also, urine hCG tests may give a false negative result in very dilute urine. It has been reported that certain drugs such as diuretics and promethazine (an antihistamine) may also cause false-negative urine results.
In non-pregnant women, hCG levels are normally undetectable. During early pregnancy, the hCG level in the blood doubles every two to three days. Ectopic pregnancies usually have a longer doubling time. Those with failing pregnancies will also frequently have a longer doubling time or may even show falling hCG concentrations. hCG concentrations will drop rapidly following a miscarriage. If hCG does not fall to undetectable levels, it may indicate remaining hCG-producing tissue that will need to be removed. hCG is also used to monitor treatment in patients with trophoblastic disease and to detect recurrent disease after treatment is complete. During therapy, a falling hCG level generally indicates that the cancer is responding to treatment, while rising levels may indicate that the cancer is not responding to therapy. Increased hCG levels after treatment may indicate a recurrence of disease.
A low hCG level with a confirmed pregnancy could indicate:
- Miscalculation of pregnancy dating
- Possible miscarriage or blighted ovum
- Ectopic pregnancy
I hope this information has helped you and answered your question. I wish you well.
Brenda
