What Causes Infertility


  • 32

    Male Factors

  • 32

    Female Factors

  • 23

    Unexplained Causes

  • 11

    Male & Female Influences

  • Admittedly we do not have the exact number of reasons for infertility. However, we have summarized the most common culprits (and some that are not so common), so by the time you’re done here there won’t be very many that you haven’t at least heard mentioned.

    It might be tempting to assume that most of the trouble is with the woman. Given that the female reproductive system is more extensive than that of the male, there does seem to be a larger number of medical terms describing female problems. However, more than one study has found that the actual numbers of cases of infertility attributed to men and women are not far apart. A UK study reported male factors and female factors each at 32.5%. Cases that had multiple male and female influences were 10.8%. Unexplained cases made up 23.1% of the total. The remaining 1% or so involved “other factors” whatever that means.

    Since there are fewer entries on the list of male reasons for infertility, we start with that. At the top of the list is low sperm count or sperm that aren’t healthy and are not sufficiently mobile. The environment in which the sperm are created is important; stress, improper diet, smoking, obesity and sexually transmitted diseases can all contribute to circumstances where the body is unable to create a sufficient number of healthy sperm. There is perhaps little reason to spend a lot of money on infertility treatments if the man is unwilling to first take a good look at improving his health in these areas.

    Other reasons for male infertility problems are if the testicles have not descended properly and if there is a varicocele, which is basically varicose veins in the testicles. The veins down there are supposed to send blood back up to the heart; little one-way valves make sure the blood goes in the right direction. However if they malfunction the circulatory system gets messed up and the ability to produce healthy sperm is diminished. There are various ways to treat this, with varying levels of success, depending on the nature of the problem.

    Finally there can be plumbing problems in the tubing through which the sperm must travel on their mission. Thus, there may be an ample number of healthy sperm to begin with, but not enough find their way to the finish line.

    The most likely reasons for infertility in women relate to the ovulation process. Luteal phase defect (LPD) means that, for a variety of reasons, the duration of the ovulation process is shortened. Those reasons can include hormone imbalances, obesity, prolonged use of oral contraceptives and stress.

    Pelvic inflammatory disease (PID) is another potential source of trouble. Blocked fallopian tubes, endometriosis (which can cause blocked tubes), uterine fibroids and PCOS.

    The female factors that cause infertility may be breakdown as follows: 40% tubal and pelvic pathology, 40% ovulatory dysfunction, 10% unexplained infertility, and finally, 10% with unusual and rare problems. The remaining 20% of couples fall into the category of unexplained infertility.

    infertility causes in women

    Statistics on the causes of infertility in women.

    Weight can be an issue, although perhaps not as often as one might think. It may be a major factor less than 10% of the time, but if you are in that 10% it is worth attention. There are two reasons for infertility related to obesity. First it turns out that fat cells produce estrogen, which in excess can shorten the luteal phase and/or sabotage the ovulation process. Also, the same hormonal/chemical influences that can cause excess weight can also cause PCOS, a major hurdle to pregnancy.

    Some of the same causes of male infertility can affect women as well, such as alcohol, smoking, stress, sexually transmitted diseases and bad diet.

    The healthy diet and bad habits can be worked on before spending a lot of money on sophisticated infertility treatments, but we recommend consulting a doctor if in doubt.