Hormone production and distribution are influenced by various factors. Stress, certain medications, weight or thyroid disorders could for instance have a negative impact on hormonal balance. If there is an imbalance in the body’s hormone levels, this has a significant influence on the natural process of a woman’s menstrual cycle. Egg maturation and subsequent ovulation may for instance be inhibited or not take place at all.
Infertility due to the fallopian tubes
After ovulation, the egg lands in the fallopian tube. In the fallopian tube the sperm then have the opportunity to fertilise the egg. In approximately one third of women, the fallopian tubes are damaged or obstructed, which causes involuntary childlessness. The delicate fallopian tubes can for example be damaged due to inflammation, previous ectopic pregnancies or adhesions after an operation. Endometriosis – spontaneous proliferation of the lining of the uterus outside of the uterus – can also clog the fallopian tubes and prevent the sperm from reaching the egg.
Tumours inside the uterus
Benign growths in the uterine muscle can grow inside the uterus, in the uterine wall or outside the uterus. Depending on the position and size, these harmless tumours can have an influence on fertility. Inside the uterus, these occupy the area where a fertilised egg should implant on the endometrium. Should the myoma (or fibroid) press against the fallopian tubes or the cervix, fusion of the egg and sperm becomes more difficult. In addition, typical symptoms of myomas, such as intermenstrual bleeding and inflammation, have a negative influence on fertilisation and embryo implantation.
Abnormalities in the reproductive organs
The reproductive organs must be intact so that a sperm can fertilise the egg. In about 5% of women, abnormalities in the ovaries, fallopian tubes or uterus are the cause of infertility. The abnormalities are usually hereditary and occur in different forms.
Antibodies against sperm
If the man’s sperm enter the woman’s body, they are sometimes initially perceived as undesirable foreign objects. Antibodies in the cervical mucus of the uterus then start fighting the sperm and slow them down. This process, which prevents fertilisation of the egg, is called an immunological problem.