Endometriosis occurs when the uterine lining (endometrium) grows outside the uterus. This can lead to inflammation and reduced fertility. About 5 to 10% of all women suffer from endometriosis. Fertility is not only impaired, but the risk of complications during pregnancy and miscarriage is also increased.

In many women, the detached tissue, called endometriotic lesions, can shed unnoticed and without pain. In others, these tissue remnants cause inflammation, cysts, and adhesions, leading to varying degrees of menstrual pain as well as pain in the affected areas. The pain is often cramp-like and may be accompanied by nausea, vomiting, or diarrhea.

Polycystic Ovary Syndrome (PCOS) is one of the most common hormonal disorders affecting women of reproductive age. In Europe, 5 to 10% of women are affected, often without realizing it. Although the name suggests "many cysts", PCOS actually involves numerous follicles that do not mature properly due to hormonal imbalances.

Women with PCOS often have low levels of FSH (follicle-stimulating hormone) and high levels of LH (luteinizing hormone). Due to the FSH deficiency, the follicles fail to mature. Ovulation does not occur, and no progesterone (corpus luteum hormone) is produced. Menstrual cycles in affected women are usually very long, with infrequent or absent bleeding. Additionally, 75% of women with PCOS have increased insulin resistance.

The elevated insulin levels, necessary for glucose uptake, stimulate androgen production in the ovaries, leading to higher concentrations of male hormones (androgens).

Symptoms:
PCOS is characterized by irregular or absent menstrual periods. Ovulation often does not occur. Triggers can include mild overweight and elevated androgen levels. Other symptoms include acne and increased body hair growth.

The fallopian tubes connect the ovaries to the uterus. They are crucial for fertilization because the egg travels through the fallopian tube, where it is fertilized by the sperm in the ampulla of the tube. However, fallopian tubes can become blocked, scarred, or stuck together due to inflammation and infections (commonly chlamydia or gonorrhea) or due to endometriosis.

Hormonal disorders are usually recognizable by changes in the menstrual cycle. Bleeding may be absent, irregular, or there may be spotting and breakthrough bleeding. Thyroid dysfunctions are often a cause of infertility. Thyroid hormones influence the cycle, female fertility, and the brain development of the unborn child.

Hypothyroidism
Cause: often Hashimoto's thyroiditis
Symptoms: fatigue, dry eyes, hoarseness, constipation, or weight gain
Impact on female fertility: cycle disorders, prolonged cycle, rare bleeding or ovulation, miscarriages

Hyperthyroidism
Cause: often Graves' disease
Symptoms: high blood pressure, heart arrhythmias, nervousness, weight loss, diarrhea, excessive sweating, sleep disorders, hair loss, exhaustion, mood swings
Impact on female fertility: cycle disorders

Hyperprolactinemia (increased prolactin levels)
Cause: often hypothyroidism, medications (antidepressants), stress
Impact on female fertility: cycle disorders, no or rare egg maturation

Hyperandrogenemia (increased male hormones)
Possible causes: PCOS, androgenital syndrome (metabolic disorder), ovarian tumor
Impact on female fertility: lack of egg maturation and absent ovulation

Luteal phase defect (progesterone deficiency)
Symptoms: spotting in the second half of the cycle, too short luteal phase, sleep disturbances
Impact on female fertility: problems with embryo implantation. The luteal hormone (progesterone) is responsible for the implantation of the fertilized egg.

Myomas are common benign lumps in the uterus. Nodules in the uterine cavity or wall can make embryo implantation more difficult. Depending on their size, they can be removed through minimally invasive surgery.

Polyps are benign and usually harmless growths of the uterine lining. They often shed during the next menstrual period. However, a poorly positioned polyp can affect fertility. Polyps can be removed by curettage.

Symptoms: Myomas or polyps are often unnoticed.

The uterus is an inverted pear-shaped muscular organ, a smooth cavity lined with mucosa where an embryo can develop. Any malformation of the uterus can affect fertility. There are different types of malformations:

Uterus arcuatus: The heart-shaped uterus is the mildest form of malformation. Here, the upper part of the uterus has a small indentation, giving it a heart-like shape. It appears to have no impact on female fertility or implantation.

Uterus septus: A partition of varying length and thickness is present inside the uterus. This can restrict fertility and increase the risk of miscarriage.

Malformations can be treated surgically, making natural pregnancy possible.

Premature menopause is the permanent end of the menstrual period before the age of 40. It occurs when the ovaries no longer regularly release eggs and ovulation stops. Premature menopause is accompanied by a hormonal adjustment in the female body.

Symptoms: While some women experience no symptoms, others suffer from common menopausal symptoms such as hot flashes, mood swings, and night sweats.

Possible causes: Genetic abnormalities, autoimmune diseases, viral infections, surgical removal of the ovaries and uterus, chemotherapy or radiation therapy, and toxins such as tobacco.

The cause of female infertility can also lie in a disrupted immune response of the female body. The immune system mistakenly identifies the embryo as a foreign body and attacks it as an intruder.