Can Cyclogest cause a positive pregnancy test?

Cyclogest is a natural progesterone supplement which comes in a pessary form for insertion into the vagina. It is most commonly used to help prevent miscarriage in patients undergoing IVF. Progesterone in secreted by the corpus luteum following ovulation in the normal menstrual cycle. The corpus luteum secretes this hormone for approximately 14 days, then it degenerates and the level of progesterone in the body falls off. This loss of progesterone causes the sloughing of the inner lining of the uterus (which is the menstrual period). If a woman becomes pregnant, then the hormone hCG is secreted by the newly formed child. The hCG stimulates the corpus luteum to continue secreting progesterone, which allows for the continued support of the lining of the uterus and allows the embryo to implant and survive.

By the end of the first trimester, the placenta begins secreting its own progesterone, and the corpus luteum is no longer needed. A common reason for early miscarriage is inadequate secretion of progesterone by the corpus luteum. This is why progesterone supplementation is commonly given early in pregnancy to woman who are at high risk for miscarriage. It is the hCG that is detected by pregnancy testing, not progesterone. Use of Cyclogest would therefore NOT cause a positive pregnancy test. I would recommend that the progesterone levels in your pregnancy be measured and supplementation provided according to whether and how much is needed. This is an integral part of NaPro Technology, the new science that is ordered towards diagnosing and treating problems associated with a woman’s menstrual cycle and fertillity.

Dr. John Gisla