Which category accounts for 10% of infertility cases?

• A. Female factors
• B. Male factors
• C. Unexplained
• D. Primary infertility

Answer: (C)

Unexplained infertility is identified when a full fertility workup does not reveal a cause despite normal evaluations. After testing semen quality, confirming ovulation, and checking for tubal patency and uterine anatomy, if no problem is found, the infertility is labeled unexplained. This category accounts for about 10% of infertility cases, reflecting the limitations of standard tests and the possibility of subtle issues not detected by routine assessments (such as mild endometriosis, subclinical ovulatory disturbances, or nuanced sperm function problems).

The other categories point to identifiable issues: female factors involve ovulation or tubal/uterine problems; male factors involve abnormal semen or related issues; primary infertility simply means the couple has never conceived, rather than indicating a share of cases.