The testes produce between 100 and 200 million new sperm every day.
Environmental and medical history factors may also contribute to decreased fertility.
Unlike women, who are born with a limited number of eggs, men produce new sperm every day. The testicles produce between 100 and 200 million new sperm every day, so men are not at risk of running out of sperm as they age. Decreased male fertility can be caused by several factors, including medical conditions, environmental factors, lifestyle, and age.
Dr Archana Dhawan Bajaj, gynecologist, obstetrician and IVF expert at Nurture IVF Clinic, New Delhi, said that various medical conditions can affect sperm production or the ejaculation process. These include infections such as epididymitis, anatomical problems such as varicocele (inflammation of the veins that drain the testicles and which can affect sperm production), and problems with sperm release. Chromosomal abnormalities that result in abnormal development of the male reproductive organs, problems with sexual intercourse or ejaculation, such as erectile dysfunction, premature ejaculation or painful sexual intercourse, and DNA fragmentation (in which the DNA of the sperm is abnormal, resulting in which increases the risk of failed conception or miscarriage) are also important medical causes.
Environmental and medical history factors may also contribute to decreased fertility. Certain medications, including testosterone replacement therapy, cancer treatments such as chemotherapy and radiation, some antifungal medications, and ulcer medications, can affect sperm production. Previous surgeries such as hernia repairs, scrotal or testicular surgery, prostate surgery or vasectomies can block the path of sperm. Excessive exposure to industrial chemicals, heavy metals, or radiation can also affect fertility.
Lifestyle choices play a crucial role in male fertility. The use of illegal drugs such as anabolic steroids, cocaine or marijuana, and habits such as drinking alcohol and smoking contribute to lower sperm count. Obesity can have a direct impact on sperm and cause hormonal changes that affect fertility.
The decline in male fertility with age is not as dramatic as in women, but it is still significant. Studies show that the chances of not becoming a father increase as a man ages and pregnancy rates decrease. For example, men over 40 are 30 percent less likely to achieve fatherhood in one year than men under 30. Men over 45 take on average five times longer to become fathers than men under 25. For men over 35, the rate is 25 percent, compared to 52 percent for men under 35.
