How Stress is Related to Infertility - Research Paper Example

?How stress is related to infertility (the psychological and physical/biological issues/effects of stress on women) Introduction It has been observedby many physicians and research scholars that childlessness is a major factor for distress, in most couples, that cannot conceive for some reason. Both the condition of childlessness and the subsequent fertility treatments are known to cause stress, and it is a well established fact that infertility can abet psychological stress, especially within women (Lalos, 1999). Often it has also been seen that certain environmental factors like various biological, behavioural, physical, chemical, and other socioeconomic elements create an atmosphere of stress that may in turn have an adverse effect on the reproductive health and development of an individual. As for example, a survey on the reproductive health of the female inmates within the various concentration camps was seen to have been adversely affected (Negro-Vilar, 1993, 59). In this article I will study these various environmental stress causing factors to find out as to how stress creates infertility amongst women, by studying various books and medical journals. Discussion What is stress? Infertility is ranked by various researchers as being one of the highest levels of stress generators in an individual’s life, and is often compared to the levels of stress caused by various terminal diseases, like cancer (Domar, 1996). While studying the links between stress and infertility, it has been observed that infertility in almost all cases creates stress, while on the other hand stress does not always result in infertility amongst women. This is owing to the fact that often severity of the stress may form to be an important factor in determining its effects on human reproductive system. Stress is related to various environmental factors; and one can define the term environment in the manner that Claude Bernard frames it, “the totality of physical, chemical, biological, behavioral and socioeconomic factors or conditions that constitute the external milieu surrounding the human organism” (cited in Negro-Vilar, 1993, 59). The term "stress" generally alludes to a variety of responses created by some detrimental or potentially detrimental stimuli. A large number of these stimuli come directly from the environment; while some may arise from the responses of a particular individual to certain environmental factors; and some of the responses may also be purely psychogenic in nature. Relation between the detrimental environment stimuli and the human body (related to the reproductive system): Fig 1: “Environmental agents interact with and/or affect reproductive tissues and functions through a variety of receptors linked to different organ systems” (Source, Negro-Vilar, 1993, 60). Summarily, the sensory system of a human body interprets the various stimuli or signals originating from the environment, such as smell, touch, light, sounds, etc. and changes them into ‘chemical signals.’ These resultant chemical signals tend to influence the neuro-endocrine system, which controls the human reproductive system, and associated sexual bearing (Martin and Reichlin, 1987). The nervous and neuro-endocrine systems in a human body also control the psychological and behavioural impact on reproduction (ibid). Thus, we find that it is the neuro-endocrine system that is in complete control of the human reproductive functioning, while the hormones form a kind of chemical link between the human genetic structure and the environment (stress originating factor) (fig 1). The human immune system also responds to various ‘antigenes’ within the environment, which can adversely affect the human reproductive system. The human skin, respiratory canal, and the gastrointestinal tracts form the routes through which various detrimental environmental factors and other biologically active harmful elements may enter a human body (Fig 1). Their ultimate destination are the receptor cells and the human enzymes, and also to some extent the human genes, which are associated with the cell regulation and the functioning of the human reproductive tissues. The enzymes that take part in the metabolism of all the biologically active substances or toxins, present within a human body, are also targeted by these environmental factors. Thus, one can deduce that reproductive health of a human female may be directly affected by the various biological agents or toxins present within the body, or it may be indirectly affected by the different elements or factors coming from the environment that first affect other human organs or tissues, that may have some sort of an indirect regulating or supportive association with the reproductive organs (fig 1). Often it has also been observed that “cultural, occupational, and many other behavioural differences can modify or sensitize the stress response and the ensuing change in reproductive function” (Negro-Vilar, 1993, 61). Various experimental data on human beings suggest that often chronic symptoms of stress may lead to ‘anovulation’ or ‘amenorrhea’ in women (Barnea and Tal, 1991); while also causing decreased sperm count and change in morphology amongst male individuals (McGrady, 1984). In this context, we will now focus on the various adverse effects that stress may have on the human female reproductive system. Stress and its effects on the female reproductive system: Various preclinical studies have shown that that stress factors can produce long-term effects on the female neuro-endocrinal system (Kaufman, et al. 2000). “Stress involves the reciprocal and differential reactions of the hypothalamic–pituitary–adrenal (HPA) axis and the noradrenergic and adrenergic nerves to different types of ‘stressors’ and also the physiological differences between male and female response” (Campagne, 2008, 198) (Fig 2). Stress mediators can produce effects that may either be harmful or beneficial for the human body, depending on the time and place of their secretion. In long term they create an “allostatic overload”, which means that a transformation takes place that shifts the balance of some of the human physiological systems, leading to adverse results that in turn negatively affect the human fertility system (McEwen, 2005). Fig 2: Schematic central response to stress and inhibition of the hypothalamic-pituitary-gonadal (hpg) axis. According to the recent researchers besides the HPA axis, other neurological and hormonal systems like the hypothalamicpituitary-gonadal (HPG) axis or the sympathetic-adrenalmedullary system also tend to get affected by stress factors (Source: Campagne, 2008, 198-199). Sanders and Bruce 1999 in their papers first established a link between stress originating from psychosocial causes and female fertility, which remained separate from stress hormone levels. However, not much success has been achieved in attempts to find a single direct link between stress and infertility. As we have already seen, the HPA and the HPG axis interacts with stress hormones that directly affect human female fertility (Berger, 1996) (fig 2), such as “GnRH, prolactin, LH and FSH, as well as with hormones that may interfere indirectly with fertility, such as cortisol, endogenous opioids and melatonin” (Campagne, 2008, 198). The very fact that some analogous neurotransmitters and nuclei cells within the human hypothalamus controls and regulates stress and reproduction, elevates the chances for complementary intervention by the stress hormones on the female reproduction system, thus increasing probable chances of infertility with increased stress. There are quite a good number of research evidences that support the fact that chronic emotional stress (often along with sudden changes in eating behaviours) may lead to cause severe anovulation, a form of reproductive disorder (Seibel and Taymor, 1982; Harrison, 1983; Edelman and Golombok, 1989). This disorder that is generally categorised as hypothalamic amenorrhea, actually represents a large range of disorders that are related to the female reproductive system. Cortisol that is generally considered to be a biological indicator of stress in a human body, are found in high amounts in women suffering from hypothalamic amenorrhea, thus drawing a link between stress and infertility (Berger, 1996). Psychological stress is generally considered by the scholars to be a major factor for causing infertility amongst women (Wright, et al., 1989, 2); and psychological stress is generally found to be high amongst childless couples. ‘Psychological amenorrhea’ is seen frequently amongst women whose lives and occupations create a large amount of stress, and these women are typically found to remain single, underweight, with a history of drug abuse. Such female patients when clinically examined, generally show changes in their opioid tone and a disrupted ‘circadian’ format of cortisol secretion (Quigley, et al., 1980). It has also been observed that patients with chronic anovulation and amenorrhea tend to suffer from high levels of stress and eating disorders, both. This is mainly owing to the fact that under conditions of stress and eating disorders, there is a general decrease in the pulse generation by LHRH which ultimately results in the decrease of gonadotropin secretion and the gonad functioning (Barbarino, et al., 1989). Eating disorders like anorexia nervosa and bulimia show many of the same systemic problems as are observed in patients suffering from infertility problems, such as opioid peptides, aminergic systems, LHRH, and CRF. These aforementioned systems are normally involved in the control of various functions, like reproduction, eating behaviours and other individualistic functions of female individuals, thus also linking eating disorders with infertility. Often stress from over-exercising may result in the malfunctioning of the various systems mentioned above, like the opioid system or the aminergic system. Thus we find that there is a close link between psychological stresses, physical exercises, and eating habits, which are in turn cited as the primary causes for female infertility. Intense exercise has been known to cause amenorrhea, especially seen in women athletes (Cumming and Rebar, 1983) along with several other disorders like oligomenorrhea, delayed onset of menarche, inadequate luteal phase, anovulation, and secondary amenorrhea (Seifer and Collins, 1990). “Many of the brain hormones involved in stress responses and reproductive functions (e.g., CRF, LHRH, opioids) are also present in the placenta and can affect placental hormone secretion and function” thus leading to early pregnancy failures, in many female patients. However work still needs to be done in the context of the link between early miscarriages and stress factors, as no direct evidence of any link between them has yet been established by the scientists. Conclusion Psychological stress and other stress factors arising from various physical and biological disorders are closely connected to the female reproductive system in humans, leading to infertility in many cases. A review of the literature on this issue shows us that as regards developing basic research knowledge on this topic of stress and infertility, there has been remarkable progress. This is quite evident from the various well-designed prototypes that have been created by the different researchers while explaining the effect of the stress factors or stressful situations on the reproductive system of a female subject. However, there is a greater problem that needs to be solved which would involve delineating the ‘confounding variables,’ since it has been seen that stress that has been discussed in the above discourse can be easily associated with many other human disorders. 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Wright, J., Allard, M., Lecours, A., and Sabourin, S. 1989. Psychological distress and infertility: a review of controlled research. Int. J. Fertil. 34: 2. Read More