Common causes of infertility?

Many people face problems with conception, this can be attributed to a number of contributing factors, but not all can be diagnosed.  In 25-30% of cases a cause cannot be identified even after the most thorough investigations. This is due to the fact that some of the factors cannot be assessed.

Common causes of infertility include problems with ovulation (whereby the body does not release eggs naturally), issues with the tubes, or for male partners this would include issues with the quality or ability of the sperm.

Depending on the issue, a range of treatment options are available.

Common causes of infertility

Weight

Being overweight or obese reduces both male and female fertility. In women, being overweight can affect ovulation. Being underweight can also have an impact on fertility, particularly for women who are not ovulating due to being severely underweight.

Sexually transmitted infections (STIs)

There are several STI’s that can cause infertility. For example chlamydia can damage the fallopian tubes in women and cause swelling and tenderness of the scrotum (the pouch containing the testes) in men.

Smoking

As well as affecting your general and long-term health, smoking can also adversely affect fertility. Read more information about quitting smoking.

Stress

If either you or your partner are stressed it may affect your relationship. Stress can contribute to a loss of libido (sex drive), which in turn can reduce the frequency of sexual intercourse. Severe stress may also affect female ovulation and limit sperm production.

Female Infertility Problems

The common female infertility problems are due to the following:-

Tubal blockage

The fallopian tubes are the tubes in which an egg travels along from the ovary to the womb. The egg is fertilised as it travels down the fallopian tubes. When it reaches the womb, it is implanted into the womb’s lining where it continues to grow. If the womb or the fallopian tubes are damaged, or stop working, it may be difficult to conceive naturally. This can occur following a number of factors. Some blockages can be treated by micro-surgical techniques, but in other cases, pregnancy can only be achieved with IVF – see below for details of IVF.

Endometriosis

Endometriosis is a condition where tissue that is the womb lining, known as the endometrium starts growing in other places, such as the ovaries. During menstruation, bleeding occurs from this tissue and this can cause abdominal pain and painful intercourse. This can cause infertility because the new growths form adhesions (sticky areas of tissue) or cysts (fluid-filled sacs) that can block or distort the pelvis. These make it difficult for an egg to be released and become implanted into the womb. Endometriosis can cause infertility because it can disturb the way that a follicle (fluid-filled space in which an egg develops) matures and releases an egg.

Ovulatory problems

Ovulatory problems are the most common cause of female infertility and occur due to hormonal imbalance. This may be from within the hypothalamus, the pituitary gland, or in the ovaries. Common causes of this include stress, weight loss or gain, polycystic ovarian disease and an increased amount of prolactin production (hormone that creates milk production in the breasts).

Polycystic ovaries

Polycystic ovaries (PCO) is a condition that affects 20% of women. Many women with PCO have normal cycles and no problems conceiving. PCO is when an increased number of small cysts are under the surface of the ovary, as seen on an ultrasound.

Some women have a condition known as polycystic ovarian syndrome known as PCOS. This causes women to have a hormone imbalance with irregular or absent periods and they may have difficulty conceiving because they are not ovulating regularly.

Treatment can involve the use of medication to correct the hormone imbalance and to stimulate ovulation, or weight loss if the woman is overweight. Laparoscopic ovarian drilling – where tiny holes are made on the surface of the ovaries using diathermy or laser, may be performed before an IVF treatment cycle is started.

Age or thyroid problems

In addition, there are also a number of other factors which can limit a women’s chance of conceiving. These include age, problems with an under or overactive thyroid and side effects from some medication.

Male Infertility Problems

Common male infertility problems are usually identified either in the physical abnormalities of the reproductive tract or abnormalities of the sperm itself. In a high number of cases the causes of male infertility are unknown. During investigations a semen analysis is conducted to check the number, activity and shape of the sperm. Here are some of the most common issues affecting men:

Semen

  • Decreased number of sperm – you may have a very low sperm count, or no sperm at all.
  • Decreased sperm mobility – if you have decreased sperm mobility, it will be harder for your sperm to swim to the egg.
  • Abnormal sperm – sometimes sperm can be an abnormal shape, making it harder for them to move and fertilise an egg.
  • Many cases of abnormal semen are unexplained, but there are several factors that can affect semen and sperm.

A normal analysis of the semen should show a sperm count of more than 20 million sperm per millilitre with 50% of the sperm active and 30% of normal shape.

Testicles

The testicles are responsible for producing and storing sperm. If they are damaged it can seriously affect the quality of your semen. This may occur if you have, or have had in the past, any of the following:

  • an infection of your testicles
  • testicular cancer
  • testicular surgery
  • a congenital defect (a problem with your testicles that you were born with)
  • undescended testicles (when one or both of your testicles has not descended into the scrotum)
  • trauma (injury) to your testicles

Absence of sperm

Your testicles may produce sperm, but it may not reach your semen. The absence of sperm in your semen is known as obstructive azoospermia. This could be due to a blockage in one of the tiny tubes that make up your reproductive system, which may have been caused by an infection or surgery. This can be due to lack of hormonal stimulation of the testes by the pituitary gland. Blood tests are done to check the hormone levels and this can be treated with hormone therapy.

Hypogonadism

Hypogonadism is an abnormally low level of testosterone, the male sex hormone that is involved in making sperm. This could be due to a tumour, taking illegal drugs or Kallman’s syndrome (a rare disorder caused by a faulty gene).

AntiSperm Antibodies

AntiSperm Antibodies is when there are anti-sperm antibodies in the semen that bind to the sperm that affect their ability to penetrate and fertilise an egg. This can occur following a vasectomy, previous infections or injuries. The success rates for male infertility have improved since Intra-Cytoplasmic Sperm Injection has been introduced.

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