How is infertility defined in most guidelines?

• A. Inability to carry a pregnancy to term
• B. Infrequent intercourse
• C. 24 months
• D. Failure to conceive after 12 months of regular unprotected intercourse (6 months if woman is 35 or older)

Answer: (D)

Infertility is defined by the failure to conceive after a period of regular unprotected intercourse. Most guidelines use a 12-month window to start evaluation (6 months if the woman is 35 or older) because many couples conceive within a year, though age accelerates the need for earlier assessment. The option that states the failure to conceive after 12 months of regular unprotected intercourse, with the earlier threshold for age 35 or older, directly reflects this standard definition. The other descriptions don’t fit: carrying a pregnancy to term refers to pregnancy loss rather than inability to conceive, infrequent intercourse isn’t about the timing of conception attempts, and 24 months is an overly long waiting period before evaluation.