This is the second article of a series presented by NBH on the Menstrual Cycle and Progesterone.
At the time of egg release, the FSH (follicle stimulating hormone) begins to gradually decline and the LH (luteinizing hormone) prevails to assist in maintaining an embryo should fertilization have occurred. But, equally and likely more important the follicle cyst that released the egg is converted into a “corpus luteum” meaning that it now produces, besides estrogen, a very important hormone, progesterone. It is progesterone that will support the fertilized egg by keeping the uterine lining thick, rich in blood and nutrients that are transferred to the early placenta.
Should the egg not be fertilized in the fallopian tube on its way to the uterus, then the levels of estrogen, progesterone and LH will gradually decrease and the menses will begin because of lack of support from these hormones. This part of the menstrual cycle is an average of 14 days as is the first part of the ovulation cycle also about 14 days.
Should the levels of progesterone be very low, what is now called the “luteal phase” this not only doesn’t support the pregnancy and can lead to a miscarriage but also will create “estrogen dominance” with a multiple number of symptoms, the most common known as Premenstrual Syndrome. This is associated with pre menstrual tension, bloating, weight gain, mood swings, irritability and depression, all to varying degrees.
Some women will have symptoms at the time of ovulation, 4-5 days or so before the menses or sometime the entire 14 days and even during the first 2-3 days of the menses. A common term given to this deficiency of progesterone by infertility clinicians is “luteal phase defect”. This progesterone deficiency will also many times be associated with heavier, shorter and/or irregular cycles.
A total absence of progesterone can be associated with no menses at all, commonly seen in patients with PCOS (polycystic ovarian syndrome). The obvious treatment for PCOS, frequent miscarriages, PMS or any other estrogen dominant condition is progesterone supplementation. (PCOS patients can have the other extreme also, i.e. heavy bleeding, cramping and headaches ore any combination of these symptoms.)
Since PCOS is an extreme deficiency of progesterone, there needs to be some discussion as to the process that is taking place. PCOS actually does not originate as an ovary problem but from “insulin resistance.” The ovary is merely a target of the process. All normal ovaries also make a little bit of the androgen testosterone, a male sex hormone. The pancreas is an organ that makes the hormone insulin. High levels of insulin can also cause the ovaries to make more of the hormone testosterone which results in increase in hair, weight gain. Testosterone is converted in the fat to estrogen by the enzyme Aromatase.
Many adolescents with PCOS have higher levels of the hormone insulin in their blood. Higher levels of insulin can sometimes cause patches of darkened skin on the back of your neck, under your arms, and in your groin area (inside upper thighs).
If you have any questions about the menstrual cycle or progesterone, please email your question or questions to firstname.lastname@example.org.
By Dr. NBH, FACOG, AACS, AACG
NBH Lifetime Health Weight Loss & Hormones