The mechanisms by which<unk>  may cause<unk>  are not clearly understood, particularly when the extent of<unk>  is low. Proposed mechanisms involve an interplay of genes, hormones, inflammatory and immune mediators. Some examples of pathways are: *Retrograde menstruation. In the normal menstrual cycle, the blood goes down the cervix to the vagina. Sometimes, part of this menstruation can go through the tubes and get out the abdominal cavity, and cause a cyst of endometrius. *Cells metaplasia, so the transformation of the cells into endometrial tissue. *Anatomical distortions and adhesions (the fibrous bands that form between tissues and organs following recovery from an injury) impair oocyte production and ovulation, decrease sperm motility, and lead to disordered myometrial contractions that can affect fertilization and embryo transport. Increased levels of adhesion molecules have been found in serum of women with<unk> . These molecules include VCAM-1, ICAM-1, metalloproteinases, MMP-2, MMP-3, MMP-7, and MMP-9. *Advanced stages of<unk>  and, in particular, cases of endometriomas where the endometrial tissue is growing in and around the ovary can cause reduction of ovarian reserve. One proposed mechanism of this pathway is that toxic products secreted from the endometrioma may have detrimental effects on maintenance of oocytes. *The release of factors from endometriotic cysts which are detrimental to gametes and affect sperm function. An endometriotic cyst contains free iron, reactive oxygen species, proteolytic enzymes and inflammatory molecules. Follicular density in tissue surrounding the endometriotic cyst has been consistently shown to be significantly lower than in healthy ovaries, and to a degree that does not appear to be caused merely by the stretching of surrounding tissues owing to the presence of a cyst. * Women with<unk>  show increase in inflammatory markers in their peritoneal fluid, specifically within the pelvic area. Altered peritoneal fluid that surrounds ovaries can have oxidative DNA damage to oocytes and be harmful to an embryo. Furthermore, increased levels of circulating cytokines and chemokines can contribute to an overall inflammatory state. Some of these cytokines include interleukin-1β, interleukin-6, tumor necrosis factor, monocyte chemoattractant protein 1, and RANTES. This chronic inflammatory state can lead to fibrosis that is a commonly seen in<unk> , often presenting as adhesions. *Epigenetic alterations of CYP19A1 gene may cause deregulation in cumulus cells in infertile women with<unk> , leading to altered ovarian follicles and impaired oocyte quality. For other unknown reasons,<unk>  is more likely to develop in infertile women, and thus be a secondary phenomenon. It is preferable to speak of<unk> -associated<unk> " rather than any definite<unk>  caused by<unk> " because association does not imply causation.
Endometriosis and infertility
Diabetes and pregnancy
Hinduism and abortion
Lupus and pregnancy
symptoms of Endometriosis
symptom of Pregnancy
Infertility in polycystic ovary syndrome
Early pregnancy bleeding