The most common overall cause of female infertility is the failure to ovulate, which occurs in 40% of women with infertility issues.
Ovulating infrequently or not at all accounts for most cases of infertility. Problems with the regulation of reproductive hormones by the hypothalamus or the pituitary gland or problems in the ovary can cause ovulation disorders.
– Polycystic ovary syndrome (PCOS). PCOS causes a hormone imbalance, which affects ovulation. PCOS is associated with insulin resistance and obesity, abnormal hair growth on the face or body, and acne. It’s the most common cause of female infertility.
– Hypothalamic dysfunction. Two hormones produced by the pituitary gland are responsible for stimulating ovulation each month — follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Excess physical or emotional stress, a very high or very low body weight, or a recent substantial weight gain or loss can disrupt production of these hormones and affect ovulation. Irregular or absent periods are the most common signs.
– Primary ovarian insufficiency. Also called premature ovarian failure, this is usually caused by an autoimmune response or by premature loss of eggs from your ovary, possibly as a result of genetics or chemotherapy. The ovary no longer produces eggs, and it lowers estrogen production in women under age 40.
– Too much prolactin. The pituitary gland can cause excess production of prolactin (hyperprolactinemia), which reduces estrogen production and can cause infertility. This can also be caused by medications you’re taking for another condition.