Each of these factors is essential to become pregnant:
You need to ovulate. To get pregnant, your ovaries must produce and release an egg, a process known as ovulation. Your doctor can help evaluate your menstrual cycles and confirm ovulation.
Your partner needs sperm. For most couples, this isn’t a problem unless your partner has a history of illness or surgery. Your doctor can run some simple tests to evaluate the health of your partner’s sperm.
You need to have regular intercourse. You need to have regular sexual intercourse during your fertile time. Your doctor can help you better understand when you’re most fertile.
You need to have open fallopian tubes and a normal uterus. The egg and sperm meet in the fallopian tubes, and the embryo needs a healthy uterus in which to grow.
For pregnancy to occur, every step of the human reproduction process has to happen correctly. The steps in this process are:
One of the two ovaries releases a mature egg.
The egg is picked up by the fallopian tube.
Sperm swim up the cervix, through the uterus and into the fallopian tube to reach the egg for fertilization.
The fertilized egg travels down the fallopian tube to the uterus.
The fertilized egg implants and grows in the uterus.
In women, a number of factors can disrupt this process at any step. Female infertility is caused by one or more of the factors below.
Ovulation disorders, meaning you ovulate infrequently or not at all, account for infertility in about 1 in 4 infertile couples. 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.
Premature ovarian failure. Also called primary ovarian insufficiency, this disorder is usually caused by an autoimmune response or by premature loss of eggs from your ovary (possibly from genetics or chemotherapy). The ovary no longer produces eggs, and it lowers estrogen production in women under the age of 40.
Too much prolactin. The pituitary gland may cause excess production of prolactin (hyperprolactinemia), which reduces estrogen production and may cause infertility. Usually related to a pituitary gland problem, this can also be caused by medications you’re taking for another disease.