Infertility is a medical condition characterized by the inability to conceive after 1 year of regular unprotected intercourse in women under the age of 35, or 6 months of unprotected intercourse in women over the age of 35. It can be caused by male factors, female factors, or both. It is most frequently due to female factors such as ovulatory dysfunction, fallopian tube dysfunction, or endometriosis. Male factors include hypogonadism, medical side effects (e.g., finasteride), testicular varicoceles (dilated veins), or genetic defects in sperm.
Male or female patients can also develop infertility due to pituitary adenoma. This is a pituitary tumor that results in hypogonadism and breast enlargement in men and menstrual irregularities in women. Hypogonadism in men can cause symptoms such as breast enlargement, lower energy levels, loss of libido, and erectile dysfunction.
Infertility is caused by male factors, female factors, or both. The most common male factors associated with infertility include:
- Low testosterone – hypogonadism
- Post-testicular defects
- Abnormalities of the seminiferous tubules
Low testosterone levels may be due to the use of medications such as Propecia (finasteride) or Aldactone (spironolactone). Patients with scrotal varicoceles may also develop infertility – varicoceles are dilated veins in the scrotum that could potentially lead to impaired semen production. Prior testicular trauma is also a risk factor. Infectious diseases such as mumps (orchitis) can also lead to testicular failure in some patients.
The most common female factors associated with infertility include:
- Ovulatory dysfunction
- Fallopian tube dysfunction
- Cervical abnormalities
Ovulatory dysfunction can be due to abnormalities in hormone levels. The reproductive hormones in women are much more complex and tightly regulated than those in men, even minor changes can result in infertility. Abnormalities of the fallopian tubes, endometrium, and cervix can all result from abnormalities in these organs at birth or damage from trauma, surgery, or infection.
Both men and women can potentially develop infertility from thyroid dysfunction (e.g., hypothyroidism) or pituitary tumors (prolactinomas). Occasionally, no cause of infertility is identified in a couple.
A large study found that between the years 2006-2010, about 6% of American women between the age of 15-44 experienced infertility. Other estimates suggest that the prevalence of infertility is approximately 12%-18%. A study in developed countries demonstrated that female infertility occurs in 37% of cases, male infertility occurs in 8% of cases, and infertility in both occurs in 3% of cases. An estimated 5% of infertility cases go unexplained.
- Practice Committee of American Society for Reproductive Medicine. Diagnostic evaluation of the infertile female: a committee opinion. Fertil Steril 2012; 98:302. – https://www.ncbi.nlm.nih.gov/pubmed/25936238
- Dancet EA, D’Hooghe TM, van der Veen F, et al. “Patient-centered fertility treatment”: what is required? Fertil Steril 2014; 101:924. – https://www.fertstert.org/article/S0015-0282(14)00302-1/pdf
- ESHRE Task Force on Ethics and Law, including, Dondorp W, de Wert G, et al. Lifestyle-related factors and access to medically assisted reproduction. Hum Reprod 2010; 25:578. – https://www.ncbi.nlm.nih.gov/pubmed/20085914