Causes of Infertility
There are many factors that affect fertility.
There are four elements that are required for pregnancy – sperm, eggs, a means of the sperm and egg to meet (usually via the fallopian tubes) and a place for the embryo to implant and grow (uterus). Issues that affect any of these elements can make conception difficult.
Sperm related factors include:
- Azoopsermia – This is the complete absence of sperm in the ejaculate. It can occur secondary to a genetic condition, history of chemotherapy, previous vasectomy or a blockage/absence of the connecting conduits that take the sperm from their site of production in the testes into the semen. Depending on the cause, it may be possible to obtain sperm and achieve a pregnancy.
- Oligospermia – This is the technical term for a low sperm count. Sperm counts below a set level can make natural conception difficult. This is usually a condition that can be effectively managed, through intra-uterine insemination, IVF or intra-cytoplasmic sperm injection (ICSI, in which a single sperm is injected into an egg)
- Poor quality sperm – There are a number of conditions that can result in poor quality sperm. It is often possible to identify and treat the issue, and consequently achieve a healthy pregnancy.
Egg related factors include:
- Irregular or absent ovulation, in other words, an egg isn’t released naturally each month. Depending on the cause of the irregular or absent ovulation, it is often possible to force the ovaries to start ovulating. It may be as simple as taking tablets (ovulation induction) or if this is not effective, by using low dose hormone injections. In some cases, IVF may be required.
- A complete absence of eggs in the ovaries – This is also referred to as premature ovarian failure or premature menopause. It is a very rare condition. If you are concerned you may be experiencing premature ovarian failure, it is essential that you seek treatment as soon as possible.
- Poor quality eggs – This can be a very tricky condition to treat. It is most commonly associated with increasing female age. There are no tests currently available to test the quality of eggs, aside from conducting ovarian stimulation, collecting eggs and attempting to fertilize them. If you suspect that your eggs may be of low quality, you should seek an opinion from a fertility specialist.
- Low ovarian reserve – This may be genetic, due to previous medical treatment (ovarian cyst removal or chemotherapy) or age-related. Achieving pregnancy is often possible despite a low ovarian reserve. Many women with a low ovarian reserve continue to ovulate normally and hence natural conception may be possible, with or without monitoring. If you have reason to suspect you have a low ovarian reserve, you should seek an opinion from a fertility specialist as soon as possible.
Fallopian tube related factors:
- Blockage of the the fallopian tubes may occur due to a history of surgery, endometriosis or pelvic infection. Fallopian tubes may also be blocked for no identifiable reason. A simple test, called a HyCoSy, can be used to determine if the fallopian tubes are blocked. If they are blocked, pregnancy can be achieved with IVF.
- Fallopian tubes may be surgically removed to treat an ectopic pregnancy or occasionally due to infection or severe endometriosis. If the fallopian tubes have been removed, IVF will be required in order achieve pregnancy.
Uterine related factors:
- Structural issues – These encompass abnormalities present from birth such as an abnormally shaped uterus (eg, a uterus with a septum) or abnormalities acquired during life such as fibroids or polyps within the uterine cavity. Often these abnormalities can be corrected surgically.
- Thin lining of the uterus or adhesions (scarring) within the uterus – These issues tend to occur secondary to surgery or infection, although occasionally they may occur without an obvious cause. Surgical correction may be possible.
- Immunological abnormalities – This is a very complex area that is not fully understood. Some immunological abnormalities that greatly increase the likelihood of miscarriage can be easily treated.
- Endometriosis – This may decrease fertility by a number of mechanisms including distorting the pelvic anatomy so the fallopian tubes become distorted and blocked, by reducing the ovarian reserve (number of eggs in the ovaries) or by creating a hostile environment within the uterus. The effects of endometriosis in regards to fertility can frequently be overcome through surgery and/or IVF.
- Medical conditions – When a person is systemically unwell, fertility can be affected. By working with a multi-disciplinary team of experts in their own individual medical or surgical field, management of medical conditions is optimised. Risks of pregnancy whilst affected by a medical condition is discussed. Pregnancy is often possible to achieve, with integrated obstetric care pre-arranged to optimise pregnancy outcome for both mother and baby.