What Are Common Causes of Infertility?

Medically Reviewed on 1/31/2022
What Are Common Causes of Infertility
Infertility can affect both men and women, and various causes can lead to the condition. Learn about what causes infertility in both men and women

According to the World Health Organization (WHO), infertility is a disorder of the reproductive system that causes a failure to achieve pregnancy after one year of regular unprotected sexual intercourse. 

Infertility can affect both men and women, and various causes can lead to the condition, which is categorized into two types.

  1. Primary infertility: Occurs when a couple has never conceived.
  2. Secondary infertility: Occurs when a couple has had at least one successful pregnancy previously but has failed to conceive again.

What causes female infertility?

  • Fallopian tube damage: Damage to the fallopian tubes can prevent contact between sperm and eggs and can be caused by pelvic inflammatory disease, endometriosis, pelvic surgery, sexually transmitted infections, and tuberculosis of the uterus.
  • Irregular menstrual cycle: During a normal menstrual cycle, an egg is released from the ovary, leading to a thickening of the endometrium in preparation for a potential pregnancy. However, hormonal imbalances can disrupt the menstrual cycle, which can in turn lead to infertility. Irregular menstrual cycles can be caused by:
  • Uterine deformity: Abnormal anatomy of the uterus caused by fibroids or polyps can lead to infertility.
  • Cervical problems: Cervical problems can inhibit the ability of sperm to pass through. Causes include excess mucus production or altered cervical anatomy due to surgery.
  • Medications and drugs: Chemotherapy or radiation therapy, long-term use of nonsteroidal anti-inflammatory drugs, antipsychotic medications, and use of marijuana or cocaine can negatively impact female infertility.

What causes male infertility?

  • Low sperm count (less than 20 million/mL)
  • Complete absence of sperm cells (azoospermia) in ejaculation
  • Poor sperm motility (asthenospermia), in which sperm moves slowly or does not move in a straight line
  • Abnormal sperm morphology caused by certain genetic diseases
  • Medical conditions such as retrograde ejaculation, varicocele, inability of the testicles to descend into the scrotum, antibodies destroying the sperm cells, or hormonal imbalance that causes low testosterone levels in the body
  • Chemotherapy, calcium channel blockers, tricyclic antidepressants, anabolic steroids, or recreational drug use


Men and women are equally likely to have fertility problems. See Answer

What are risk factors for infertility?

While causes of infertility are often genetic, certain factors can increase the risk of infertility for both men and women:

  • Age: Female fertility decreases with age, causing a lower number and quality of eggs. Men over age 40 are also less fertile than younger men.
  • Tobacco: Tobacco use can decrease the chances of fertility. Miscarriage is often observed in women who smoke.
  • Alcohol: Excessive alcohol consumption can contribute to infertility, especially for men. It tends to decrease sperm motility and count.
  • Weight: An inactive lifestyle and being overweight or underweight can disrupt fertility.
  • Thyroid dysfunction: Hypothyroidism or hyperthyroidism can hinder fertility.

What are treatment options for infertility?

Consulting with a medical professional is an absolute must when it comes to treating infertility conditions. Potential treatment options may include:

  • Assisted reproduction techniques
    • Intrauterine insemination (IUI): Usually recommended when the man suffers from infertility issues or the woman has an abnormal cervix. IUI can be done by donor insemination (DI) or artificial insemination by the man (AIH).
    • In-vitro fertilization (IVF): Sperm and eggs are taken from the couple and incubated in a dish in a controlled lab environment to produce an embryo. The embryo then gets placed in the woman's uterus for implantation.
    • Intracytoplasmic sperm injection (ICSI): Treats sperm-related infertility problems and involves injecting a single sperm into a mature egg.
    • Zygote intrafallopian transfer (ZIFT): Fertilized eggs are transferred into the fallopian tube within 24 hours of fertilization to maximize the chances of a successful pregnancy.
  • Surrogacy and gestational carriers
    • If the woman is unable to carry a successful pregnancy or produce healthy eggs, the couple may be advised to choose surrogacy or gestational carriers.
    • With surrogacy, another woman is inseminated with sperm from the male partner. The resulting child will be biologically related to the male partner and the surrogate mother.
    • With a gestational carrier, the implanted embryo belongs to the female partner and not the carrier. This method is usually recommended when the female partner produces healthy eggs but is unable to carry a successful pregnancy.
  • Lifestyle changes
    • Eating a diet high in whole grains, fruits, and vegetables and low on processed foods, added sugars, and saturated fats.
    • Limiting alcohol and avoiding active and passive smoking.
    • Regularly exercising and maintaining a healthy weight.
    • Reducing stress and practicing breathing techniques

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Medically Reviewed on 1/31/2022
Image Source: iStock Images

World Health Organization. Infertility. https://www.who.int/news-room/fact-sheets/detail/infertility

Dave CN. Male Infertility. Medscape. https://emedicine.medscape.com/article/436829-overview

Puscheck EE. Infertility. Medscape. https://emedicine.medscape.com/article/274143-overview

National Institutes of Health. What are some possible causes of female infertility? https://www.nichd.nih.gov/health/topics/infertility/conditioninfo/causes/causes-female