WHAT IS THE MENOPAUSE? – UNDERSTANDING THE FEMALE REPRODUCTIVE SYSTEM AND MENSTRUAL CYCLE

​Menopause happens when you have not had a period for 12 consecutive months.  Menopause actually only lasts for one day!
 
Perimenopause is the period leading up to menopause where the symptoms are likely to be the most noticeable and where bodily changes occur.
 
During perimenopause there are changing levels of the female hormones oestrogen and progesterone.
 
Menopause is a natural part of ageing and marks the end of the female reproductive years.
 
There are a number of types of menopause:  natural, surgical, and premature.
 
Natural menopause is exactly what it says on the tin:  it is a normal part of the ageing process.  The reproductive cycle begins to slow down and prepares to stop.  As menopause approaches, the ovaries produce less oestrogen.  This causes periods to become irregular and then stop, and you may notice other symptoms which will be discussed in a later podcast.
 
Whilst menopause lasts one day and 12 months from your last period, perimenopause can last 8-10 years.  The time after menopause (post-menopause) continues until the end of your life.  The average age of menopause is 51 years.
 
To understand menopause, it is helpful to go back to basics and understand the reproductive cycle and the role of hormones.
At birth a female has approximately 1-2 million eggs in her ovaries. By puberty, only around 300,000 remain, and of these only about 500 will be ovulated during your reproductive lifetime.
 
Did you know that it is only humans and whales that have a menopause?!
 
Women of reproductive age experience cycles of hormonal activity that repeat at about one month intervals.  With every cycle, a woman’s body prepares for a potential pregnancy, whether or not that’s the plan.
 
The term “menstruation”refers to the periodic shedding of the lining of the womb (uterus).  “Mestru” means monthly.
 
The average menstrual cycle takes about 28 days and occurs in phases:  FOLLICULAR PHASE, OVULATORY PHASE, LUTEAL PHASE.
 
Four major hormones that stimulate/regulate the cells/organs’ activities:  FOLLICULE STIMULATING HORMONE (FSH), LUTEINISING HORMONE (LH), OESTROGEN, PROGESTERONE.
 
The follicular phase starts on day 1 of the period when FSH and LH are released from the brain, travelling in the blood to the ovaries.  These hormones stimulate the growth of 15-20 eggs in the ovaries, each in its own shell, called a follicle.  FSH and LH also trigger an increase in the production of oestrogen.
 
As oestrogen levels rise, like a switch, it turns off production of FSH.  This careful balance of hormones allows the body to limit the number of follicles that mature.
 
As the follicular phase progresses, one follicle in the ovary becomes dominant and continues to mature.  This dominant follicle suppresses all other follicles.  As a result, they stop growing and die. The dominant follicle continues to produce oestrogen.
 
The ovulatory phase starts approximately 14 days after the follicular phase started.  This phase is the midpoint of the menstrual cycle, with the next menstrual period starting about 2 weeks later.  The rise in oestrogen from the dominant follicle triggers a surge in LH produced in the brain, which causes the follicle to release the egg from the ovary.  As the egg is released, known as ovulation, it is captured by the finger-like projections on the ends of the fallopian tubes, which sweep the egg into the tube.
 
Also during this phase, there is an increase in the amount and thickness of the mucus produced by the cervix.  If you were to have intercourse during this time, the thick mucus captures the sperm, nourishes it, and helps it move towards the egg for fertilisation.
 
The luteal phase begins right after ovulation. Once it releases an egg, the empty follicle develops into a new structure called the corpus luteum which secretes progesterone.  Progesterone prepares the uterus for a fertilised egg to implant.  If the egg is fertilised, it will travel through the fallopian tube to implant in the uterus, and the woman is considered pregnant.  If the egg is not fertilised, it passes through the uterus, the lining of the uterus breaks down, and the next menstrual period begins.
 
I hope this helps with understand why and how periods happen.  I will be giving you more information about the hormones, difference between perimenopause and menopause, common symptoms of perimenopause, what causes some of the more common symptoms, what you can do about it, and links to useful websites.