Fertility: Function, Tasks, Role & Diseases

Fertility describes the ability of living things to provide offspring. In man, it is the ability to procreate; in woman, it is the ability to conceive, carry to term, and bear a child.

What is fertility?

Fertility describes the ability of living things to provide offspring. The biological ability to reproduce is called fertility. It is influenced by internal and external factors. Human fertility begins with the onset of puberty and declines with age. Female fertility ends with menopause, which begins around age 45 and lasts for several years. Male fertility, on the other hand, can continue into old age. It is not uncommon for men to remain fertile until 70 or beyond. Wealth and the resulting healthy diet have an influence on fertility in a particular age group. For women, the childbearing age is usually between the ages of 15 and 49. In developing countries, women over the age of 45 give birth more frequently than in industrialized nations. However, people’s reproduction is always related to the society in which they live. Due to demographic aging and long periods of education, fertility cycles are shifting in industrialized nations. In addition, family planning, i.e. pregnancy that is deliberately induced or prevented, has an influence on the fertility of a population.

Function and purpose

Human reproduction depends on the time at which sexual intercourse occurs between a man and a woman, unless contraceptive methods are used. Complex processes take place in the woman’s body that prepare it for a possible pregnancy, defined by the term female cycle. The cycle lasts an average of 28 days and is characterized by a menstrual period of about six days. It is divided into ovulation and the period after ovulation, which lasts until menstruation. Before ovulation, several eggs mature, one of which is always released, sometimes more. The egg travels through the fallopian tube to the uterus, but must pass through the cervix before implantation. This is sealed with a mucus plug at the beginning of the cycle so that no sperm can pass through. When estrogen levels rise, the mucus liquefies and sperm can pass through. When estrogen levels are highest, ovulation is triggered. The egg is transported through the fallopian tube towards the uterus. Sperm can now travel unimpeded into the uterine cavity and fallopian tube. During this time, a slight increase in temperature can be noticed. The egg remains capable of fertilization for 12 to 24 hours after ovulation. After ovulation, the follicle changes under the influence of the hormone LH to the corpus luteum, which then produces progesterone. This, together with estrogen, causes optimal preparation of the uterine mucosa for implantation of the egg. The cervical mucus also becomes more viscous and seals the cervix again. If fertilization has not taken place, the corpus luteum perishes about 14 days after ovulation. Now less estrogen and progesterone is produced and the built-up uterine lining is shed with the next menstruation. A new cycle begins.

Diseases and ailments

Fertility is affected by many different factors. Even if couples who wish to have a child calculate the most fertile days for the woman, pregnancy does not necessarily occur during planned intercourse. This is because, in addition to all the medical possibilities, both the psyche and lifestyle play a significant role in conception. The biology of both partners can be just as decisive for a supposed infertility as stress, for example. The cause of unwanted infertility lies in equal parts, namely 40% in the man and the woman, 15% in both, and in 5% even experts cannot discover a clear cause. The probability of pregnancy decreases with age and even decreases continuously from the age of 25. From the age of 38, the probability of pregnancy decreases rapidly. Lifestyle also has a major influence on pregnancy. Smokers have a significantly higher risk of miscarriage than non-smokers, the ratio is 3:2. Smoking also increases the concentration of toxins in the cervical secretions and makes it more difficult for sperm to penetrate.Male sperm quality also decreases due to nicotine, coffee and alcohol. Doctors found that heavy coffee drinkers get pregnant significantly less often than women with low coffee consumption. Coffee lowers hormone production in the ovaries. Larger amounts of alcohol have a detrimental effect on health and directly on the male and female reproductive organs. Drugs are also suspected of reducing the likelihood of fertility because they alter hormone balance. Pollutants such as lead, cadmium and mercury also affect fertility. Pesticides and radioactive radiation have equally harmful effects on the human organism, but their direct influence on fertility is not so easy to prove. Last but not least, metabolic diseases such as diabetes, kidney, liver and thyroid dysfunction, and cancer have an impact on fertility. Almost always, they also interfere with hormone balance and thus alter organ function. Cancer therapy can also lead to infertility due to radiation exposure. Often, unwanted infertility can be treated successfully. Different methods are available for infertility treatment, and their risks are also assessed differently.