Your Menstrual Cycle and Your Hormones
Your menstrual cycle and your hormones
Your hormones are driving your fertility signs: Each of your fertility signs is directly related to cyclical hormonal changes and processes. Your hormones are also responsible for triggering the responses needed to prepare your body for conception and a possible pregnancy.
Hormones are biochemical substances that are produced in one area of your body and carried in your bloodstream to send signals that trigger responses in another part of your body.
The fundamental hormones that drive your menstrual cycle are:
• Gonadotropin-Releasing Hormone (GnRH)
• Follicle Stimulating Hormone (FSH)
• Estradiol / Estrogen
• Luteinizing Hormone
These hormones are produced in the following area:
• Hypothalamus (in your brain)
• Anterior pituitary gland (also in your brain, located behind and attached to the hypothalamus)
• Adrenal glands (located on top of your kidneys)
A series of hormonal steps trigger the events of your menstrual cycle.
1. At the beginning of your menstrual cycle, the hypothalamus produces GnRH (gonadotropin-releasing hormone). The GnRH pulses through your bloodstream from the hypothalamus to the pituitary gland in spurts every 60-90 minutes from menstruation until ovulation. The GnRH signals the anterior pituitary gland to secrete FSH (Follicle Stimulation Hormone) and later LH (Luteinizing Hormone). This is what is happening during menstruation and the days before ovulation.
2. Follicle Simulation Hormone (FSH), as its name suggest, stimulates the development and maturation of follicles in the ovaries. One of these follicles will become dominant and contains the egg that will be released at ovulation. The developing follicles begin to produce estrogen (estradiol).
3. The estrogen released by the developing follicles, and later by the dominant follicle causes the lining of the uterus, the endometrium, to grow and thicken in preparation of implanation of a fertilized egg.
4. By about the seventh day of your cycle on average (but this can vary widely), the dominant follicle takes over. The egg within the other follicles loses its nourishment and dies along with the follicular cells.
5. The dominant follicle produces a sharp rise in estrogen. (You can recognize this stage of your cycle by closely monitoring your cervical fluid). Estrogen is at its peak one to two days prior to ovulation.
6. This oestrogen surge signals the release of LH (Luteinizing Hormone). This is the hormone that is measured by ovulation predictor kits (OPKs). LH travels through the bloodstream to the ovary where it causes the ovary to release enzymes that make a hole in the sac that is the dominant follicle. This causes the dominant follicle to rupture and release the egg into the Fallopian Tube where it can be fertilized. This is ovulation. The LH surge is necessary for ovulation to occur. The LH surge (the highest concentration of LH) occurs 12-24 or prior to ovulation but LH begins to rise about 36 hours before ovulation.
7. Estrogen drops dramatically after ovulation.
8. The dominant follicle, transformed by LH, becomes the corpus luteum after ovulation. This phase of your cycle after ovulation is called the luteal phase since hormone production is governed by the corpus luteum continues to produce a small amount of oestrogen, but also produces progesterone. Progesterone is the hormone that dominates this phase of your cycle. Like estrogen, progesterone is needed to develop the endometrium so that the fertilized egg can implant and be nourished should fertilization occur. Your BBT (Basel Body Temperature) rises as a result of progesterone production.
9. If an egg is fertilized and implantation of the fertilized egg occurs, the corpus luteum’s life is extended. In conception cycles, the corpus luteum keeps on producing progesterone and some estrogen and the development of the endometrium continues. The pregnancy hormone HCG begins to be produced when the fertilized egg implants, at around 7-10 days past ovulation. As the pregnancy progresses, hormone production is taken over by the placenta.
10. If there is no pregnancy, the corpus luteum dies, progesterone levels fall and a new cycle begins.
Your Hormones and your Fertility Signals
Each of the fertility signals that you observe when you chart your fertility corresponds to a hormonal process and the presence of hormones in your bloodstream. Estrogen and progesterone provide the most significant signals.
Your cervical fluid and cervical position provide clues about estrogen. Some commercial devices, such as saliva microscopes and some fertility monitors also measure the presence of oestrogen.
Your Basel Body Temperature (BBT) tells you about the presence of progesterone.
Ovulation Prediction Kits (OPK’s) and some types of fertility monitors tell you about the presence of LH (Luteinizing Hormone), the last hormone to peak before ovulation.
Hormone Corresponding Fertility Signs
Estrogen Cervical Fluid, Cervix Position, Saliva Microscope, Fertility Monitor
Progesterone Basal Body Temperature (BBT)
Luteinizing Hormone (LH) Ovulation Predictor Kit (OPK) Fertility Monitor
This is just a short extract taken from ‘Charting Your Way To Conception’ FertilityFriend.com, I would suggest you download this for information; charting will be discussed at consultation stage.