The primary purpose of the reproductive system is reproduction. Unlike other organ systems, reproductive organs vary significantly between sexes of the same species. The human reproductive system consists of both external and internal organs.
Understanding Infertility
At the outset, it is important to clarify concepts related to infertility. According to the World Health Organization, infertility is defined as the inability to achieve pregnancy after at least one year of regular unprotected sexual intercourse. Some experts broaden this definition to include women over the age of 35 who are unable to conceive after six months, or those who can conceive but are unable to carry a pregnancy to term due to recurrent miscarriages.
After 12 months of regular unprotected intercourse, 85–90% of couples will conceive, usually within the first few months of trying. The remaining 10–15% will not, which corresponds to the global infertility prevalence — approximately 10–15% of couples are infertile or experience subfertility (reduced fertility). Unfortunately, this percentage has been steadily increasing over the years. An unhealthy lifestyle and poor habits significantly affect general health, including reproductive health, in both women and men. As a result, more and more couples today face this diagnosis.
It was once commonly believed that infertility was predominantly a female issue. Today we know this is incorrect. Male-related causes account for more than 35% of infertility cases, and often, the cause is shared between both partners.
In men, the key factors for fertility are sperm quality and quantity. High-quality sperm is typically characterized by high motility — the ability of sperm cells to swim through the vagina, cervix, and uterus to reach the fallopian tubes for fertilization. Sperm count also matters — more sperm generally increases the chance of successful conception. Recent scientific studies show a progressive decline in the overall sperm count, as well as in the number of motile and morphologically normal sperm cells.
This decline is most likely due to high-stress lifestyles and environmental factors — particularly unhealthy habits such as lack of physical activity, obesity, smoking, and others. All of these negatively impact sperm quality and disrupt hormonal balance in the body.
One of the most critical fertility factors is age. In women, fertility begins to decline after the age of 30, while in men it tends to decline after the age of 45. The main difference is that men produce new sperm every three months (a process called spermatogenesis), while women are born with a finite number of eggs (approximately 200 million) that decrease over time through ovulation and age. Additionally, egg quality diminishes due to various environmental and health-related factors, including unhealthy lifestyle habits.
Factors that negatively impact normal spermatogenesis include dietary estrogens, genital heat (or cold), and radiation (even from mobile phones). Several of these factors can act synergistically to impair fertility. Tight clothing, prolonged cycling, keeping a mobile phone in the front pocket, and temperature extremes around the testicles can all damage sperm production. It has been proven that external factors such as bisphenol A, sulfur dioxide, and carbon monoxide adversely affect male fertility.
