Female infertility can be caused by several factors. One of the most common ones is related to problems in the ovarian cycle, which end up turning into ovulation complications or menstrual irregularities.
In general, issues related to egg production and maturation occur as a consequence of hormone alterations, as the ovarian and menstrual cycles are regulated by hormones. This is the reason why this cause of female infertility is known as endocrine factor sterility.
Displayed on this image, one can see the negative feedback system: the hypothalamus releases GnRH to promote the releasing of FSH and LH by the hypophysis or pituitary gland. The hormones of the pituitary gland exert their action on the ovary, triggering ovarian maturation and ovulation with it.
As oocytes grow and develop, the releasing of estrogens increases, which has an impact on the hypothalamus and the pituitary gland by blocking their action. An ovary that is not capable of releasing neither GnRH, FSH and LH stops producing estrogens. In turn, this lack of estrogens promotes the releasing of GnRH, FSH, and LH, thereby starting a new hormonal cycle.