Today it is known that some of the factors of the sterility Not only are they related to physical problems, they also include factors such as stress and some addictions, such as smoking , the alcoholism and the drug addiction .
In 2000 the ISSSTE disseminated information from the University of Copenhagen, Denmark, in which it was revealed that the average concentration of sperm fell from 113 million per milliliter in 1938 to 66 million per milliliter in 1990. This is most likely due to contaminants chemical
According to the same studies, women are less exposed to these phenomena. However, cigarette and alcohol alter ovarian irrigation and can cause early menopause. Stress also hinders ovulation and may lead to lack of menstruation.