A 34-year-old woman presents to her physician complaining of difficulty conceiving. Upon further evaluation, she reports a regular menstrual cycle but has been unsuccessful in achieving pregnancy for the past 12 months. Her medical history is unremarkable, and she denies any significant past illnesses or surgeries. Physical examination reveals no abnormalities. Laboratory investigations reveal normal hormone levels and ovarian reserve. However, a semen analysis report of her partner is attached. what is the initial diagnosis of the husband?