In the case of the female partner there are several factors which can impede achieving pregnancy:
Obstruction of fallopian tubes
In one third of women inability to conceive is caused by an obstruction or injury to the tubes: they can be partially or completely obstructed or damaged in a way that their function is impaired. In most cases, the tubes are damaged or affected by previous inflammations.
Polycystic ovary syndrome (PCO)
This hormonal disorder is connected to numerous symptoms. Primarily, irregular or absent ovulation is the reason for the failure to achieve pregnancy.
Absence of ovulation
The individual hormonal balance is very important in order to get pregnant. Hormonal disorders can lead to failure in oocyte maturation, an absence of ovulation, as well as poor development the corpus luteum (which consequently results in nidation failure).
Reduced ovarian reserve
Unfortunately the majority of women are not aware that their ovarian reserve decreases over the years. The decision to have children is often postponed until the time is right. By the time this moment finally arrives and all the requirements are met, fertility can be already be severely diminished or even nonexistent.
Endometriosis is the growth of the endometrium outside the uterus. It is still unknown why this happens. Endometriosis manifests itself via extreme pains during menstruation and often during intercourse.
Thyroid disorders can lead to irregular cycles, reduced fertility, increased risk of abortion and reduced mental and physical development of the fetus.
Antibodies against semen
Sometimes antibodies against semen can be found in the cervical secretion. Therefore the sperm cells are already destroyed on their way to the uterus and cannot reach the fallopian tubes which means that fertilization does not occur.