Causes of Infertility

Female Factor

There are many factors that can increase a woman's risk of infertility. Female factor infertility is most often caused by:

  • Problems with ovulation
  • Advanced maternal age
  • Poor diet and lifestyle
  • Irregular menstrual cycles


Approximately 40% of women with infertility have some type of ovulation disorder. Polycystic Ovarian Syndrome is one of the most common causes of infertility due to lack of ovulation. Without ovulation, there are no eggs to be fertilized. Some signs that a woman is not ovulating normally include irregular or absent menstrual periods. Women who have low body weight or who exercise heavily may also stop having regular menstrual cycles.

Blocked fallopian tubes account for over 30% of infertility diagnosis in women. There are several reasons why a woman's fallopian tubes may be blocked:

  • Pelvic infection which is also known as PID (pelvic inflammatory disease)
  • A ruptured appendix
  • Previous tubal surgery
  • Ectopic pregnancy (a pregnancy that develops outside of the uterus)
  • Infection after previous surgery for a miscarriage or a pregnancy termination
  • Endometriosis (where tissue from the uterus grows in other areas of the pelvis (i.e. tubes, ovaries). Many women with this condition have severe pain and cramping, most typically in the days leading up to the menstrual cycle. Endometriosis may lead to decreased fertility and may affect the quality of a woman's eggs.
  • Asherman's Syndrome (scar tissue within the uterus). This may occur after a pelvic infection or may occur after surgery to the uterus such as a dilation and curettage ("D&C").
  • Fibroids. Fibroids may grow in a location within the uterus that prevents an embryo from implanting. Fibroids may also cause miscarriage.


This is the most profound factor influencing fertility. In women, there is a subtle decline in fertility starting in the late 20's. In the years between age 38 and 40, fertility declines more rapidly. Once a woman turns forty, there is a significant and rapid decline in fertility with each year. In women above age 45, the chance of having a baby is less than 1%. Aging decreases a woman's chances of having a baby in the following ways:

  • The ability of a woman's ovaries to release eggs ready for fertilization declines with age.
  • The health of a woman's eggs declines with age.
  • As a woman ages she is more likely to have health problems that can interfere with fertility.


Being Overweight
Being overweight can cause irregular or infrequent menstrual cycles which may increase your risk of infertility. For many who lose weight to get pregnant, a weight loss of 5% to 10% dramatically improves ovulation and improves success with fertility treatments. Being overweight may also increase your risks of complications during surgery or increase your risk of miscarriage. There is a link between obesity, excess insulin production and the infertility condition known as polycystic ovarian syndrome (PCOS).

Being Underweight
Being underweight can decrease production of gonadotropin releasing hormone (GnRH), which is essential to regular ovulation in women. This can cause ovulation to become irregular or even stop. Decreased GnRH levels can affect the development of the uterine lining and its receptivity to the implanting embryo.

Alcohol Consumption
Drinking alcohol may lead to irregular menstrual cycles and anovulatory menstruation (menstruation that occurs without ovulation).

Tobacco Smoking
Studies have shown that the prevalence of infertility is higher, and the time it takes to conceive is longer, in smokers compared to nonsmokers.

  • Smoking may accelerate the loss of eggs and reproductive function and may advance the time of menopause by several years. Components in cigarette smoke have been shown to interfere with the ability of cells in the ovary to make estrogen and to cause a woman's eggs (oocytes) to be more prone to genetic abnormalities.
  • Studies of IVF have reported that female smokers require higher doses of gonadotropins to stimulate their ovaries, have lower peak estradiol levels, fewer oocytes obtained, more canceled cycles, lower implantation rates, and undergo more cycles with failed fertilization than nonsmokers.
  • Smoking also increases your chance for a miscarriage.

While stress may not cause infertility, it can cause problem that may interfere with your fertility treatment. Stress makes many body organs work harder than normal and increases the production of some important chemicals in your body, including hormones. In an occasional woman, having too much stress can change her hormone levels and therefore cause the time when she releases an egg to become delayed or not take place at all.

Ways that you can reduce your stress while being treated for infertility include:

  • Communicate with your partner about the emotional and financial aspects of fertility treatment. Try to learn as much as you can about the cause of your infertility and the treatment options available. Find out as much as you can about your insurance coverage and make financial plans regarding your fertility treatments.
  • Realize you're not alone. Talk to other people who have infertility, through individual or couple counseling, or support groups. Read books on infertility, which will show you that your feelings are normal and can help you deal with them.
  • Moderate regular exercise can release physical and emotional tensions.
  • Learn stress reduction techniques such as meditation, yoga, or acupuncture.
  • Avoid taking too much caffeine or other stimulants.


Sexually Transmitted Diseases (STDs)

Sexually transmitted diseases such as chlamydia and gonorrhea, which are on the upswing, can cause or contribute to infertility.

Radiation Treatment and Chemotherapy

Lifesaving cancer treatments may reduce fertility by destroying eggs and sperm. The likelihood of reproductive damage depends on the age and sex of the patient and the type and duration of treatment. The most severe damage comes from radiation to the ovaries and cancer drugs such as cyclophosphamide, mechlorethamine, chlorambucil, and melphalan. Although sperm production may recover, eggs do not regenerate; their loss is permanent and premature menopause may occur as a result. The risk of developing premature menopause is lower for younger women than for older women. Your first goal is to cure the cancer, even if the treatment causes sterility. However, there are several options that may help preserve fertility before and after cancer treatments.

If time and circumstances allow, you may be treated with IVF. Embryos created by IVF are then frozen and may be stored for years. If you do not have a partner and are not able to freeze an Embryo then Oocyte Freezing (freezing your eggs) may be the best option for you. The process is similar to freezing an embryo but in Oocyte freezing, the eggs are frozen before they are fertilized. When you are ready to become pregnant, the eggs will be thawed and fertilized to create the embryo.

After your physician has advised that attempting pregnancy is safe, contact us to schedule your fertility evaluation. You may be able to conceive naturally or with fertility treatments. If significant damage has occurred to your ovaries or uterus, you may wish to consider egg or embryo donation, a gestational carrier, or adoption to create a family.

Male Factor


Male Factor infertility is most often caused by:

  • problems producing either too few sperm or none at all
  • problems with the sperm's ability to reach the egg and fertilize it
  • difficulty with erection or ejaculation

Some men are born with the problems that affect sperm. Other problems may start later in life due to illness, injury or overall health and lifestyle. If there is a suspected problem with sperm production or quality, then evaluation and treatment should occur once the problem is detected. Your physician may recommend a semen analysis to evaluate your sperm count.

Some things that may reduce sperm number and/or quality include:

Previous surgery on the testicles or in the groin region (i.e. surgery for undescended testicles or hernias)

Radiation treatment and chemotherapy. Lifesaving cancer treatments may reduce fertility by destroying sperm. The most severe damage comes from radiation to the testicles and cancer drugs such as cyclophosphamide, mechlorethamine, chlorambucil, and melphalan. Sperm production may recover from treatment. Semen samples may be frozen before starting chemotherapy or radiation therapy. Samples can be stored for years and used later for insemination. If sperm counts are low and/or the supply is limited from the frozen sample, the sperm can be used for in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Testicular biopsy may be a way to obtain sperm if sperm are not found in a semen analysis. If sperm cannot be obtained, pregnancy may be possible by using frozen donor sperm. The physician may want to wait up to six months before attempting conception.

Varicoceles (enlarged blood vessels in the area of the testicles). About 15% of all men have a varicocele. For many, it's not a problem. But nearly 40% of men who have fertility problems have a varicocele. If it is associated with infertility, it may need to be treated. Left untreated, varicoceles raise the temperature in the testicles, which may affect the production of sperm, as well as sperm movement and/or shape. Varicoceles are typically treated with surgery. Surgery helps 30% to 50% of couples achieve pregnancy naturally.

Alcohol and drugs. Excessive alcohol consumption can reduce the production of normally formed sperm needed for successful pregnancy. Narcotics (cocaine, speed, etc.) may inhibit your fertility.

Environmental toxins. If your work or hobby brings you in contact with environmental toxins or poisons (pesticides, insecticides, lead, solvents, organic fumes or radiation exposure) you may be unknowingly affecting your fertility.

Smoking. Men who smoke cigarettes have a lower sperm count and motility and increased abnormalities in sperm shape and function. Long term use of marijuana can result in low sperm counts and abnormally developed sperm.

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