Next Fertility IVF Prof. Zech

Fertility Problems

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Next Fertility IVF Prof. Zech

Fertility Problems

Causes of Infertility

Most couples are likely to get pregnant naturally. However, about 15-20% of all couples remain involuntarily childless. The causes of infertility are distributed evenly between women and men, at 45% for each. Often, combined male and female factors are responsible for a couple's failure to conceive. An ever decreasing number of couples (due to continuous improvement in diagnostics) are diagnosed with unexplained infertility, i.e. no reason was found to explain their infertility issues. This is also referred to as idiopathic infertility.

Visual depiction of unwanted childlessness in proportion to the share accounted for by male / female factor infertility │ © 2022 Next Fertility IVF Prof. Zech • Member of Next Clinics


Involuntary childlessness can have various causes, such as, for instance, hormonal disorders, pathological alterations in organs and serious diseases. Moreover, unhealthy lifestyle patterns can affect fertility.

1. Disorders in the development of ovum and sperm
2. Disorders of sperm-egg interaction
3. Problems arising after fertilization


1. Disorders in the development of ovum and sperm

Unintentional childlessness can be due to either the lack of oocyte maturation (oogenesis) or to the maturation of an insufficient number of spermatozoa (spermatogenesis). Failed oocyte maturation is usually associated with disturbances affecting the proper functioning of the endocrine gland system (hypothalamus, pituitary gland, ovaries etc.). It is necessary, first of all, to carry out hormonal testing to identify the type of endocrine disruption and treat it accordingly. The presence of spermatozoa is assessed by a microscopic investigation of the semen sample (see "sperm selection"). In order to fertilize an oocyte (fertilization), it takes millions of motile sperm. However, only a few of them actually reach the fallopian tube. In order for fertilization to occur, the oocyte in the uterine tube must be surrounded by several hundred sperm cells. If motile sperm cells a are not present in the tube in sufficient numbers, fertilization cannot take place. In most cases, the cause of this can be found not only in a hormone deficiency. In the majority of cases, disorders that affect the testes themselves are responsible for the problems. Unfortunately, these conditions cannot be treated as easily as, for example, oocyte maturation failure in women. Special examinations are needed for further diagnostics. Attempts can be made, through targeted medical treatment or hormone therapy, to increase the number and quality of motile sperm. Unfortunately there are currently no, or only limited options available for the treatment of testicular degeneration or genetic disorders.

2. Disorders of sperm-egg interaction

Even when there is a mature oocyte (oogenesis) and sufficient motile sperm cells, there are still numerous factors that may prevent sperm from fusing with the egg (fertilization). In the majority of cases, the reproductive cells cannot meet because the fallopian tubes are affected by a pathological alteration and are therefore blocked. In particular, this includes adhesions resulting from inflammation, adhesions forming a barrier between ovaries and fallopian tubes, complete absence of fallopian tubes after tubal surgery, bilateral tubal ligation for sterilization treatment. In some rare cases, immunological processes inside the neck of the womb (cervix uteri) may impair sperm motility.

3. Problems arising after fertilization

The developing embryo may die before implantation (nidation) due to development failures, which can either be inherited or acquired. Furthermore, it may also happen that the uterine lining (endometrium) is not sufficiently thick (poor endometrial receptivity) to allow for successful embryo implantation. There are also cases where maternal immune response leads to embryo rejection (embryo is recognized as foreign tissue). If the reasons for sterility remain unknown even after a comprehensive diagnostic work-up of both partners of the infertile couple, this is referred to as unexplained or idiopathic infertility. In such cases, psychosomatic aspects should also be considered besides the purely medical factors, because emotional and mental processes may have a major impact on specific bodily functions. If this is the case, it is recommended that the first step should be to seek psychotherapeutic support in order to assess the situation and subsequently initiate the appropriate steps to be successful at last (see "emotional support").

An in-depth clarification is needed to establish the causes why your dream of having a child has not yet been fulfilled. Our team of highly skilled specialists at the IVF center will be happy to evaluate your individual situation. For this purpose, a wide range of diagnostic and therapeutic options is available to them.

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