## Rare or absent ovulation This is one of the most common causes of female infertility, which can be caused by: – [Polycystic ovarian syndrome](https://ul.orna.me/KOge/librarydisease?id=57)(PCOS) – Hypothalamic dysfunction – Primary ovarian insufficiency – [Prolactin](https://ul.orna.me/KOge/librarybiomarker?id=68) levels that are too high ## Fallopian tube obstruction Damaged or blocked fallopian tubes prevent sperm from reaching the egg or block the passage of a fertilized egg into the uterus. The culprits are:=== – Pelvic inflammatory diseases – Infection of the uterus and fallopian tubes caused by sexually transmitted diseases – Previously undergone abdominal or pelvic surgery, including that associated with ectopic pregnancy ## Endometriosis Endometriosis is diagnosed when tissue that normally grows in the uterus overgrows outside of it. This pathology and its surgical removal can lead to scarring that can block the fallopian tubes and prevent the egg and sperm from connecting. Endometriosis can also make it difficult for a fertilized egg to implant. ## Problems with the uterus or cervix Both can interfere with the implantation of an egg, as well as increase the risk of miscarriage. These include: – Benign neoplasms: polyps, cysts, or tumors (myomas) – Congenital abnormalities (such as an unusual uterine shape) – Cervical stenosis (narrowing of the cervix) ## Hormonal disruption Any disruption of the endocrine system can lead to infertility. ## Excessive immune response In this case, the woman's body perceives sperm as pathogens and produces antibodies (immunoglobulins) against them. ## Being underweight or overweight With a small amount of fat layer, there is a failure in the rhythm of ovulation because at a low BMI, the level of estrogen decreases, and periods are lost. Excess body weight also negatively affects pregnancy. Even if conception occurs, there is an increased risk of fetal failure, as fatty tissue is a source of inflammation. ## Long-term use of combined oral contraceptives After withdrawal of OCs, a woman may not have menstruation and ovulation, as in 1-2 % of cases a syndrome of hyper inhibition of gonadotropic function of the pituitary gland develops. > The question of when to seek help from a doctor depends on the age of the woman. Up to 35 years of age, it is worth trying to conceive for one year before taking tests or undergoing treatment. Between the ages of 35 and 40, discuss your concerns with your doctor after six months of trying. After the age of 40, it is better to get tested beforehand.