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Last updated: March 26, 2021

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Infertility is defined as the inability of a couple to conceive despite one year of unprotected sex. In many cases, both causes of male and female infertility contribute to a couple being unable to conceive. The most common cause of male infertility is a sperm disorder (e.g., impaired motility, reduced count), whereas in women anovulation and impaired fallopian tube motility are the prevalent causes. Diagnostics focus on assessing both partners for possible causes of infertility. Tests that are commonly performed include semen analysis, hormone tests for assessment of ovulatory function, and evaluation of tubal patency. Treatment focuses on the underlying cause of infertility, e.g., sex hormone substitution and administration of clomiphene citrate or gonadotropins to stimulate ovulation. Surgery is indicated if structural issues (e.g., tubal adhesions, varicocele) are present, while in vitro fertilization is used for causes of both male and female infertility.

  • Infertility: inability of a couple to conceive despite 1 year of unprotected sex
    • Primary infertility: infertility in women who have never been pregnant or in men who have never successfully conceived with a partner
    • Secondary infertility: infertility in women who have previously conceived; infertility in men who have previously induced pregnancy
  • Recurrent pregnancy loss: inability of a woman to carry to live birth even if conception is possible (e.g., caused by uterine myomas, antiphospholipid syndrome)


  • Infertility affects approx. 10–15% of couples of reproductive age. [2]
  • Approx. 5% of women in the US aged 15–44 years old are infertile. [3]
  • Approx. 5–10% of men in the US aged 15–44 years old are infertile. [4][5]

Epidemiological data refers to the US, unless otherwise specified.

Both sexes

Female infertility

Male infertility

References: [1]

Clinical findings

Diagnostics [1]


Treatment depends on the cause of infertility:


Clinical findings

  • Depend on the underlying condition



Treatment depends on the cause of infertility (see “Etiology” above).


  1. Infertility Definitions and Terminology. Updated: June 28, 2017. Accessed: June 28, 2017.
  2. Brenner S, Miller JH, Broughton WJ. Encyclopedia of Genetics. Elsevier ; 2002
  3. FastStats Homepage - Reproductive Health - Infertility. Updated: July 15, 2016. Accessed: June 28, 2017.
  4. National Health Statistics Reports, Number 51, April 12, 2012 - Fertility of Men and Women Aged 15–44 Years in the United States: National Survey of Family Growth, 2006–2010.
  5. Agarwal A, Mulgund A, Hamada A, Chyatte M. A unique view on male infertility around the globe. Reprod Biol Endocrinol. 2015 . doi: 10.1186/s12958-015-0032-1 . | Open in Read by QxMD
  6. Tarlatzis BC. GnRH antagonists in ovarian stimulation for IVF. Hum Reprod Update. 2006; 12 (4): p.333-340. doi: 10.1093/humupd/dml001 . | Open in Read by QxMD
  7. Weiss JM, Ludwig M, Ortmann O, Diedrich K. GnRH antagonists in the treatment of infertility.. Ann Med. 2003; 35 (7): p.512-22.
  8. Orvieto R, Meltzer S, Rabinson J, Zohav E, Anteby EY, Nahum R. GnRH agonist versus GnRH antagonist in ovarian stimulation: the role of endometrial receptivity. Fertil Steril. 2008; 90 (4): p.1294-1296. doi: 10.1016/j.fertnstert.2007.10.022 . | Open in Read by QxMD
  9. Johnson NP. Metformin use in women with polycystic ovary syndrome.. Annals of translational medicine. 2014; 2 (6): p.56. doi: 10.3978/j.issn.2305-5839.2014.04.15 . | Open in Read by QxMD