How do hormones in the pituitary gland and hormones in the ovaries regulate the normal menstrual cycle?
A regular menstrual cycle commences with a follicle growing in the ovaries. This growth is stimulated by a hormone in the pituitary gland (Follicle Stimulating Hormone). As the follicle grows, it stimulates the production of estradiol (a type of estrogen). The bigger the follicle, the more estradiol is produced. Once a certain level is reached, this will stimulate a sudden release of a different hormone from the pituitary gland (Luteinizing Hormone), which triggers the release of the egg. The release of the egg is ovulation.
So what changes as women get older? In early perimenopause, there is a fall in the follicular function and production. The pituitary hormone levels (FSH) will rise to try to encourage and stimulate this production. These high sustained levels of FSH can cause cycles to be long and variable. As a result, ovulation will occur less frequently in cycles. The other pituitary hormone (LH) doesn’t get triggered to release the egg. Heavy blood loss is seen in late perimenopause and is likely to be a result of raised estradiol levels for longer periods of time, leading to increased thickening of endometrial tissue. This process can occur for several years prior to menopause.
Eventually low levels of estradiol lead to the cessation of periods. Menopause is defined as 12 months without a period, and the average age that this occurs in women is 51 years.
Symptoms you might notice that suggest you are perimenopausal could include:
- Hot flushes or night sweats
- Vaginal dryness
- Heavy periods
- Sleep disturbances
- Mood changes
- Pain with intercourse
- Bladder dysfunction including increased frequency, urgency or incontinence
- Pelvic Organ Prolapse
Learn about this process so you can manage the symptoms that you might have. This will help you navigate through this period of change. Find health care providers that can help you cope with these changes.
Written by Ellen Barnett, The Physiotherapy Clinic.