Causes of Infertility

Causes of infertility at a glance

  • We give couples having trouble getting pregnant factual information about the possible causes of infertility, as well as our expert insight, so they can pursue the best solution to their individual situation.
  • Infertility affects both men and women; about 1 in 8 couples of reproductive age will experience it.
  • As with other kinds of medical conditions, specially trained physicians can treat infertility, and we often help patients succeed in attaining the family they desire.
  • Many factors can contribute to infertility, including age, lifestyle practices, overall health and the presence of certain physical or hormonal conditions.
  • Beginning with a thorough, personal interview and physical exam of both partners, our physicians use all our skills and every means possible to try to find the cause of infertility and provide treatments to overcome it.

Take our quick infertility quiz


What are the causes of infertility?

A wide range of physical or hormonal conditions and lifestyle factors may cause infertility in men and women. The definition of infertility is the inability to become pregnant after 12 months of regular, unprotected intercourse or the inability to carry a pregnancy to live birth.

If a couple or person meets this criteria, it is cause to see a fertility specialist for an evaluation. For women age 35 and older, testing for causes of infertility is recommended after six months of trying to become pregnant without success.

Infertility affects both men and women, causing about 1 in 8 couples to fail to conceive. Because it takes two to conceive, the source of the infertility varies.

  • About one third of infertility cases in a couple are caused by female factors
  • One third by male factors
  • One third by a combination of male and female factors
  • About 90 percent of the time, we identify the cause
  • But an estimated 10 percent of infertile cases are diagnosed as “unexplained infertility,” as no cause of infertility is detected despite thorough testing.

Our specialized physicians (reproductive endocrinologists) provide in-depth infertility testing to help determine the right fertility treatments for each individual’s circumstances.

Following are the primary causes of infertility in men and women, including links to more detailed information on our website. Sometimes we easily identify one cause. Sometimes we need to piece together multiple factors from both the man and woman to determine the cause.

Causes of infertility in women

Many factors affect a woman’s fertility. Below are the most common causes:

Age, the big factor

As a woman ages, the quality and quantity of her eggs, which is fixed at birth, starts to decline at a rate of about 3-5 percent each year up to age 30. By age 35, a woman’s chances of fertility drop significantly. A 40-year-old woman has about a 5 percent chance of becoming pregnant per menstrual cycle.

Ovulation disorders

These are generally the first thing physicians evaluate. Ovulation problems, including anovulation (no ovulation), account for 25 percent of female infertility cases. Ovulation disorders can occur due to a variety of factors.

Hormone imbalance

When a woman’s naturally occurring hormones are disrupted due to medical conditions, medications or other factors, an imbalance may result that interferes with her fertility.

Disorders and conditions

Structural issues

Blocked or damaged fallopian tubes, uterine abnormalities and problems with the cervix can result in infertility.

Learn more about female infertility


Causes of male infertility

Causes of male infertility include overall health and certain physical or hormonal conditions that can affect delivery, quantity and quality of sperm. Generally, the first step in determining cause of infertility in the male involves semen and sperm analysis.

Some causes of infertility in men include:

  • Sperm abnormalities­ – size, shape, volume and motility (movement ability) are important factors in male fertility
  • Infection – from sexually transmitted diseases or inflammation of the prostate or testicles
  • Varicocele – an enlarged vein in the man’s scrotum that can affect sperm quality
  • Hormone imbalance – can inhibit sperm production
  • Blockage of the sperm duct­ – the vas deferens (sperm duct) transports sperm for ejaculation
  • Retrograde ejaculation – causes sperm to travel backwards into the man’s bladder during ejaculation rather than out through the tip of the penis
  • Undescended testicles (cryptorchidism) – if not corrected can lead to low sperm production
  • Injury or trauma
  • Problems with sexual intercourse – psychological and/or physical factors may make intercourse difficult or impossible for some men, as can erectile dysfunction (ED), hypospadias, premature ejaculation and painful intercourse
  • Cancer of the reproductive organs – can cause infertility, as can cancer treatment such as radiation or chemotherapy. Fertility preservation is an option available for men to freeze sperm prior to cancer treatment.

Learn More About Male Infertility