Sexual activities can be initiated for a variety of reasons, such as the pursuit of pleasure, lust, attachment, belonging to somebody, the wish for closeness and safety. One of the basic motives in human evolution and history has been the wish for a child, i.e. procreation.
Infertility describes a situation or state between a couple and/or individuals in which this wish is not fulfilled. Infertility is a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse.
The unfulfilled wish for a child can lead to a variety of reactions which are modified by individual traits, societal and cultural norms, medical conditions, etc., and which include frustration, despair, anger, depression, anxiety, threat, social devaluation and isolation. The sexual act itself is deprived of the procreational potency.
The relationship between the sexual behavior and function of a couple and their infertility has several dimensions:
• Sexual dysfunctions which contribute to infertility
• Clinical conditions as causes of infertility and sexual dysfunction (comorbidity)
• Sexual dysfunctions during the diagnosis and treatment of infertility
In all these conditions, sexual dysfunctions can occur separately in the woman or the partner and they may influence each other and represent a cofactor.
Sexual dysfunctions contributing to infertility
One of the most obvious reasons for infertility is the absence of intercourse between the couple. This seems so clear that medical professionals may forget to ask couples whether they have intercourse at all. Most infertility specialists are aware of rare cases in which even during the course of assisted reproduction treatment it turns out that the couple has never had intercourse and they did not report it because they were ashamed to admit to this fact. Avoiding intercourse among married couples may be due to internalized religious or moral messages which condemn sexual expression as sinful.
And although most religions would allow sexual activities for the purpose of procreation, the basic concept of sex being dirty and infecting the soulmay lead to avoidance. 
Another more unconscious reason may be an inner conflict between the arranged marriage and the wish to be with another partner.
Lack of desire and even sexual aversion among women is less frequently a cause of infertility, probably due to the fact that women may respond to their partner’s sexual needs and their wish to get pregnant without feeling sexual desire or sexual excitement.
It is a physiological fact that women can become pregnant without subjective feelings of desire, excitement or orgasm.
Lack of desire or sexual aversion in men, however, can have a direct impact on the couple’s fertility, because without the male’s physiological arousal and ejaculation (orgasm) responses, pregnancy cannot be achieved in the female partner.
Some couples have tried intercourse but penetration is not possible because of vaginism of the female partner. Vaginism is a condition which involuntary muscle spasm prevents vaginal penetration, it affects about 0.5–1% of the female population.
Another contributing factor to infertility is severe premature ejaculation. This means that the male partner ejaculates before being able to penetrate and enter the vagina with his penis.
In very rare cases, men may have difficulty ejaculating in the vagina, which may either lead to very prolonged intercourse or even to a complete incapacity to ejaculate in the vagina.
To be continued...
References
1. The EFS and ESSM Syllabus of Clinical Sexology; 2013
2. Simons JS, Carey MP. Prevalence of sexual dysfunctions: results from a decade of research. Archives of Sexual Behavior-2001; 30: 177-219.
3. Derogatis LR, Burnett AL. The epidemiology of sexual dysfunctions. Journal of Sexual Medicine-2008 Feb; (2): 289-300.