Infertility may be due to factors involving either the male or the female. The main causes of female infertility include ovulatory disorders and fallopian tube factors. Ovulatory disorders may result from dysfunction in ovulation, such as changes in the hypothalamic-pituitary-ovarian axis, as well as ovarian diseases, with polycystic ovary syndrome being the most common condition that could lead to ovulatory issues. Fallopian tube factors include blockages or inefficiencies, which can also cause infertility in women. Uterine factors can also lead to infertility, including abnormalities of the uterus, inflammation of the endometrium, polyps in the endometrium, and intrauterine adhesions, all of which can affect the implantation of the fertilized egg and cause infertility. Abnormal cervical mucus secretion, cervical inflammation, and an unusual immune environment in cervical mucus that affects sperm passage can also lead to infertility. Male infertility factors primarily include disorders of sperm production and sperm delivery, which may manifest as abnormalities in semen, shown by the absence of sperm, weak sperm, or low sperm count, all contributing to infertility. Additionally, sexual dysfunctions such as premature ejaculation, anejaculation, and erectile dysfunction can also result in male infertility.