Can natural progesterone supplementation cause a false pregnancy reading?
Hi Catherine,
I was wondering if, while using natural progestrone cream, it could give a false pregnancy reading?
Thank you,
Tracy
Dear Tracy,
Bioidentical progesterone supplementation CANNOT cause a false positive in home pregnancy tests (HPTs). HPTs only check hCG levels, not progesterone. They are completely different hormones.
Human Chorionic Gonadotropin (hCG) is the “pregnancy hormone” that keeps the corpus luteum producing progesterone when conception occurs. It is produced by the placenta during pregnancy and is measured by HPTs.
A woman “usually” produces 25 milli-international units per milliliter (mIU/ml) of hCG 10 days after conception. As a general rule, hCG beta numbers should double every two to three days. Accordingly, the concentration of hCG rises rapidly, frequently exceeding 100 mIU/ml by the first missed menstrual period and peaks in the range of 30,000-200,000 mIU/ml by 8-10 weeks into pregnancy. An hCG level of less than 5 mIU/ml generally indicates that one is not pregnant.
The appearance of hCG in urine soon after conception and its subsequent rise in concentration during early gestational growth make it an excellent marker for the early detection of pregnancy.
The earliest you can get a positive result on the most sensitive pregnancy tests is seven days after ovulation. Implantation needs to occur before hCG is produced, and that generally happens between 6-12 days post ovulation, usually by 10 days after. For this reason, it makes economical sense to wait until 10-12 days after ovulation, but even then a significant percentage of women who are indeed pregnant will still show a negative result.
The only medications that can cause a false positive on a home pregnancy test are those than contain hCG itself. If you are taking fertility medications with hCG - e.g. Novarel, Profasi, Pregnyl - please consult your doctor regarding appropriate times and circumstances for testing. Other fertility drugs and medications that do not contain hCG will not precipitate false positive results. Similarly, progesterone will not cause a false positive.
