Human Chorionic Gonadotropin (HCG)
What Affects the Test
Things that may affect the results of your test include:
- Doing a urine test for human chorionic gonadotropin (hCG) very early in pregnancy (during the first week after implantation) or on a urine sample taken in the middle of the day. The test may not always show an early pregnancy.
- Miscarriage (spontaneous abortion) or therapeutic abortion. HCG results may remain high (positive) for up to 4 weeks after a miscarriage or therapeutic abortion.
- Getting an injection of hCG to treat infertility. This may cause test results to appear high for several days after the injection.
- Having blood in the urine sample or soap in the collecting container, which may change the hCG level.
- Using Reference diuretics Opens New Window and promethazine. These medicines can cause false low hCG levels in urine test results.
- Using heparin, a medicine to prevent blood from clotting (anticoagulant).
- Using some medicines. These include hypnotics (such as Ambien), antipsychotics, and antinausea medicines (such as prochlorperazine and promethazine ). Be sure to tell your doctor what medicines you take.
|By:||Reference Healthwise Staff||Last Revised: Reference April 4, 2012|
|Medical Review:||Reference Sarah Marshall, MD - Family Medicine
Reference Siobhan M. Dolan, MD, MPH - Reproductive Genetics
© 1995-2011, Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.