Infertility in women can be caused by physical problems, problems with egg production, hormone imbalance and anti-sperm antibodies. Fertility testing is usually recommended if you have been having regular sex without contraception and have not managed to get pregnant in 12–24 months. These tests look for all the obvious causes of female infertility, and your partner is also tested for signs of male infertility.
Physical causes of infertility in women include blockages that prevent the natural passage of the eggs down the fallopian tubes or abnormalities in the uterus that prevent the fertilised embryo from implanting. Both the fallopian tubes and the uterus can become blocked by pelvic inflammatory disease, fibroids or by scar tissue from previous surgery.
Infertility in women can also be the result of endometriosis, a disease in which endometrial tissue that normally lines the uterus starts to grow outside in the abdominal cavity. This can cause adhesions, blockages, damage to other organs and inflammation, which can all lead to infertility. Sexually transmitted diseases, such as chlamydia, gonorrhoea, and the cysts that develop in women with polycystic ovaries, can also damage the ovaries and fallopian tubes, causing female infertility.
Most problems with egg production are hormonal in nature; the body does not produce the correct hormones in the correct sequence required to stimulate egg production and to mature the egg. Thyroid problems can also prevent normal ovulation, and treating a thyroid condition can help treat infertility if this is the underlying cause. If normal ovulation does occur, there can still be problems with the quality of the eggs themselves, for example chromosomal deficiencies.
Even if there are no physical obstructions, and you ovulate regularly, producing healthy eggs, you can still experience infertility. In some women the cervical mucus normally thins around ovulation, allowing sperm to gain easier access to the uterus. However, in some women, this does not happen, making their cervix a far less friendly environment. Some women go even further, and produce antibodies that actively destroy sperm.
However, the most common cause of infertility in women is advancing age. Fertility falls away rapidly as you pass 35, with reducing hormone levels and fewer eggs available as your body starts to prepare for the menopause in your late forties or early fifties.