A woman’s natural reproductive years spans from the menarche (onset of puberty when the first menstruation commences) to the menopause when the menstruation ceases. The ovary is the vital and primary organ driving the reproductive process. A female has a set of two ovaries, situated in the pelvis, one on each side of the uterus attached by a ligament.
Unlike in males where the testis can maintain production of sperms through the entire life, females are born with a fixed number of oocytes (immature eggs}in the ovaries, which steadily and rapidly decline in numbers. A second trimester foetus may contain up to 20 million oocytes. The oocytes get individually housed in follicles (fluid filled cavities) which are embedded along the walls of the ovaries. As the process of follcularisation takes place, most of the eggs degenerate to the extent that at birth just around 2 million eggs are present. Fewer than a quarter of these are present at the menarche when the menstruation starts. At puberty, and thereafter at monthly intervals during the duration of fertile life, several of these oocytes begin to mature but only one of these is released as a mature egg capable of being fertilised by a sperm. During the entire lifetime of reproductive years only about 400 of the mature eggs are released.
The release of the egg from the ovary takes place during the monthly menstrual cycle. The cycle begins with the first day of menstruation (vaginal bleeding). Ideally the cycle is of 28 days but can vary by about ten days either way.
A menstrual cycle is regulated by the complex interplay of pituitary hormones {luteinising hormone, LH and follicle stimulating hormone, FSH: pituitary gland the size of a pea is situated at the base of the brain) and ovarian sex hormones (oestradiol (the most prominent and potent of the oestrogens) and progesterone; these are steroidal hormones released by the ovaries) The cycle is made of three phases: The Follicular Phase, the Ovulation Phase, and the Luteal Phase. The follicular phase, the first 14 days of the cycle is the maturation stage of the egg; the ovulation stage is the release of the egg from the ovary into the Fallopian tube for possible mating with a sperm, and the luteal phase (14 days) is the thickening of the lining of the uterus in preparation of possible implantation of the fertilised egg. The lining is shed in the absence of pregnancy, resulting in the bleeding and the debris of shed tissue.
Following the menstruation, a slight increase in FSH level stimulates several follicles, each containing an egg but only one of these will reach the full maturation and release from one of the ovaries. During the latter part of the follicular phase the level of oestradiol begins to increase. A day after Oestradiol has peaked, around day 13 of the follicular phase, a rapid surge in the levels FSH and LH marks the ovulatory phase. Ovulation (release of the egg from the follicle) takes place about 24 hours, give or take 8 hours, after the peaking of FSH and LH levels. Following ovulation, LH and FSH levels drop to base levels as the oestradiol and progesterone levels continue to rise. The ruptured follicle closes and forms corpus luteum whence progesterone is secreted. Progesterone and oestradiol cause the endometrial lining to thicken so that it is receptive to the fertilised egg in case of pregnancy. In the absence of pregnancy, the endometrial lining disintegrates to initiate the cycle all over again.
The menopause is a cessation of menstrual cycles (periods). As the number of follicles decrease with age, the amount of production of oestradiol decreases to such an extent that it is no longer able to inhibit production of FSH to maintain the cycle. The stage when cycles become irregular is termed perimenopause. The cycles during the perimenopause stage may even be anovulatory (failure to produce egg). However, during perimenopause, even in an irregular, ovulatory cycle, the pregnancy is still possible. The perimenopause stage is about 3-4 years before hitting the menopause which can be in the the normal range of 45-50 years of woman’s age, though it can occur earlier around age 40 years. eventually with all follicles depleted, the amount of oestradiol production by the ovaries completely ceases, resulting in the cessation of menstrual cycles (menopause). Menopause is the last day of menstruation. Time after a year after the menopause may be termed post menopause years. Cessation of menstrual cycles is marked with levels of pituitary hormones, LH and FSH.
Decreasing levels of secretion of oestrogen by the ovaries results in numerous of psycho-physiological symptoms, all related, directly, or indirectly to falling levels of the oestrogen. The severity of them will differ from woman to woman. From very mild to moderate to severe symptoms.
The most common symptoms experienced are hot flushes, night sweats, vaginal dryness, irregular heartbeats. There are other more secondary symptoms, like anxiety, depression, irritability, itchy skin, weight gain, bloating. Irregular oestrogen level not only cause dilation and constriction of blood vessels resulting in hot flushes and sweats, it also causes dryness in vagina, changes in blood pressure effecting heartbeat. Low levels of oestrogen effects the elasticity of the skin; it becomes thinner and prone to injury.
Another major concern is the high risk of osteoporosis after the menopause. Bone loss is very common in postmenopausal years as the protective effect of oestrogen on bones is no longer available. It is advisable for women to undertake regular bone density scans and have diet and dietary supplements to counter the adverse effects of osteoporosis.
Symptoms caused by depleted levels of oestrogen can be alleviated by administration of hormones oestrogen and progesterone, in various formulations. The hormonal treatment is more commonly known as Hormone Replacement Therapy, HRT. It can be a combined oestrogen and progesterone or oestrogen only. The treatment can be administered as a tablet, topical gel/cream, skin patches or subdermal implants. Like all medications they have side-effects, some very serious like breast cancer. The decision to receive HRT should never be taken lightly. Patients must weigh up, in consultation with doctors, the risk-benefits aspects of the treatment. HRT treatments are not advisable for women with cardio-vascular conditions, such as high blood pressure, history of blood clots, liver disease, or women with history of endometrial, ovarian or breast cancer.
In addition to HRT, which may not be suitable for everyone, there are traditionally used natural over-the-counter supplements. Effectiveness of these supplements are not always confirmed by recognised clinical trials. Herb like sage has gained popularity because of its claimed relief against hot flushes and night sweats. Other herbs like black cohosh, dong quai, red clover, St. John’s Wort, evening primrose oil are used individually or in combination formulations for relief of the symptoms. Often the herbal formulations are supplemented with vitamins and minerals.
Lifestyle adjustments that can ease the symptoms like hot flushes and sweats. maintain the room temperature at a comfortable level; dress lightly and comfortably; keep the consumption of alcohol level to minimum level and avoid smoking; eat a balanced diet, although hot spicy food should be avoided; daily, regular exercise is a must for mental and physical well-being.
The onset of menopause may seem like a great psycho-physiological shock, it need not be. Mostly the symptoms are manageable, and support and help are widely available. Healthy lifestyle can impact positively the postmenopausal years.