RELEVANCE OF MENARCHE
Menarche is the first menstrual cycle, or first menstrual bleeding, in human females. From both social and medical perspectives it is often considered the central event of female puberty, as it signals the possibility of fertility. Girls experience menarche within a range of different ages after attaining puberty. The timing of menarche is influenced by female biology, as well as genetic and environmental factors, especially nutritional factors. The average age of menarche has declined over the last century but the magnitude of the decline and the factors responsible remain subjects of contention.
Menarche is the culmination of a series of physiological and anatomic process of puberty. During this period, a number of physiological changes occur in the girl’s body wherein secondary sexual characters appear. Menarche as a discrete event is thought to be relatively a chance result of the gradual thickening of the endometrium induced by rising but fluctuating pubertal estrogen.
Puberty signals the onset of adult sexual life, and menarche means the inception of menstruation. At the start of about 8 years and usually terminating at the onset of menstruation between ages 11 and 16 years i.e. at an average age of 13 years, there is a gradual increase in gonadotropic hormone secretion by the pituitary causing the period of puberty.
In the female, as in the male, the infantile pituitary gland and ovaries are capable of full function if appropriately stimulated. However, as is also true in the male and for reasons not understood, the hypothalamus does not secrete significant quantities of growth hormone during childhood. Experiments have shown that the hypothalamus itself is capable of secreting this hormone, but there is lack of the appropriate signal from some other brain area to cause the secretion. Therefore, it is now believed that the onset of puberty is initiated by some maturation process that occurs elsewhere in the brain, perhaps somewhere in the limbic system
RELEVANCE OF MENOPAUSE
Now we can discuss about the menopause and its role in reproductive biology of human beings. Menopause is a period of permanent termination of the primary functions of the human ovaries, which are the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and later detaching of the uterine lining (a.k.a. the menses). Menopause is generally experienced in women during their midlife, which is late 40s or early 50s. This marks the end of fertile phase of a woman’s life. There is major decline in the production of female hormones by the ovaries during the change from reproductive to non-reproductive phase. It is not abrupt but phases over a period of years and is accepted to be a natural consequence of ageing. However, variations in the transition phase have been observed amongst women. In some women the accompanying signs and effects can significantly disrupt their daily activities and their sense of well-being. In addition, menopause at younger age is experienced by women who have some sort of functional disorder which affects their reproductive system (i.e., endometriosis, polycystic ovary syndrome, cancer of the reproductive organ). These functional disorders considerably hasten the menopausal process and result in health problems both physical and emotional in the affected woman.
Now we can see the changes that occur in the physiological and psychological aspects among the women. At this age, women should be ready to invite menopause by making their mind. In certain cases counseling is also necessary. At the time of menopause, a woman must readjust her life from one that has been physiologically stimulated by estrogen and progesterone production to one devoid of these hormones. The loss of the estrogens often causes marked physiological changes in the function of the body, including (1) ‘hot flushes’ categorized by extreme reddening of the skin, (2) psychic sensations of dyspnea, (3) irritability, (4) fatigue, (5) anxiety, (6) occasionally various psychotic states and (7) decreased strength and calcification of bones throughout the body. In 15% of women, these symptoms are of adequate measure to warrant treatment. If counseling fails small quantities of estrogen reverses the symptoms and with gradual tapering of the dose the postmenopausal women is likely to avoid severe symptoms.
Other Bio-events of Fertility
Here we can discuss the effects of few biological factors on human fertility. These factors include contraception, abortion and sterilization. All these factors are so important that these need careful study. In every society, now-a-days there is a tendency that family should be small, population explosion should be checked.
i) Contraception
Contraceptive practices affect fertility by decreasing the chance of conception. There is a considerable variation in the effectiveness of practicing contraceptive methods as projected in theory and while in actual use. Effective rates of more than 95% are reported using contemporary methods such as oral pills and intrauterine devices. Older methods such as condoms and diaphragm can be more than 90 per cent effective, when used regularly and correctly, but their
average use effectiveness is lower because of irregular or incorrect use. Natural methods of contraception viz. withdrawal or abstinence are also in use with variable degree of effectiveness in human groups.
ii) Abortion
Induced abortion diminishes fertility by terminating pregnancy not by affecting fecundability. Practice of abortion in human societies dates back to ages and is rather common in some settings. Statistics reveal that officially registered percentage of pregnancies terminated by abortion is more than one-third in some countries and substantial numbers of unregistered abortions are perhaps prevalent even in countries where they report very low rate.
iii) Sterilization
The complete elimination of fecundability can be brought about by sterilization. The surgical procedures of tubectomy and vasectomy have become common in diverse nations and cultures. In USA voluntary sterilization has become the most prevalent single means of regulating fertility, typically adopted by couples who have achieved their desired family size. In India sterilization has been encouraged on occasion by various government run incentive programmes.