Progesterone is a hormone named for exactly what it does: it is Pro- Gestation. It is a hormone made by the corpus luteum, that is, the cells left over in the follicle after the follicle ovulates and releases an egg. Progesterone is important for transforming the endometrium so that it is receptive to embryo implantation. If an embryo doesn’t implant and make hCG: human chorionic gonadotropin hormone, (the same hormone the home urine pregnancy tests are detecting), then the ovarian progesterone levels naturally fall. On the other hand, if hCG is being produced, it tells the ovary to continue producing the progesterone needed to support the pregnancy. Thus, some doctors order a cycle day 21 progesterone level to confirm if you have ovulated when they suspect that you may not be ovulating. A level over 3 ng/mL is indicative of ovulation.
Is there such as thing as progesterone deficiency, also commonly referred to, or compared with luteal phase deficiency? When measuring progesterone levels after ovulation, it is important to remember that progesterone is secreted in a pulsatile fashion, and it is impossible to time or predict a lab draw at your peak progesterone secretion. So even if your progesterone level only measured at 3 ng/mL, 90 minutes later it can jump 8 fold, to 24 ng/mL. So it is normal and okay to have progesterone levels on the lower side after an ovulation, it just means your progesterone was not measured at a pulsatile peak.
Rarely, your doctor may advise you to take oral progesterone. Progesterone that is taken orally undergoes first past metabolism in the liver, and thus a significant portion of the medication is degraded before it enters circulation. More commonly, some patients may be advised to take progesterone via vaginal suppository. The FDA has firm guidance that states if the medication is available in an FDA – approved prescription, those medications are preferential to compounded medications, which do not undergo the same high level of quality assurance testing and specifications that the FDA-approved medications do. You get what you pay for, and if the compounded progesterone suppository is cheaper, there is a reason why.
Many individuals are worried and nervous when they are told to taper or stop their progesterone in the first trimester. But at this point, it is okay to stop, because the baby’s placenta is making its own progesterone. In fact, it probably makes enough progesterone to support itself by the 6th week of pregnancy (2 weeks after “missed period”) but it is common practice to continue the progesterone until 9 to 10 weeks, just to cover our bases. So you can feel assured that when you stop the progesterone at the end of your first trimester, that your baby is making plenty of progesterone to grow and thrive.
For more information regarding how your progesterone affects your chances of pregnancy, please call 808-545-2800 to schedule a consultation with a physician at the Fertility Institute of Hawaii, or visit our website at https://www.ivfcenterhawaii.com/.