Male infertility: structured assessment, WHO 6th-edition (2021) semen criteria, endocrine panel, genetic cascade, and ART pathway

A 33-year-old teacher and her 31-year-old partner arrive in clinic after 13 months of trying. Her cycles are regular at 28 days, his BMI is 28, neither smokes. He has no symptoms. Your job is not to assume this is a female problem — male factor contributes in roughly half of all infertile couples, and the diagnosis sits in the semen analysis, not in the symptoms. Apply the structured assessment: history and examination of BOTH partners, two semen analyses against WHO 6th-edition (2021) limits, an endocrine panel, the obstructive-versus-non-obstructive distinction, and a genetic cascade that respects the autosomal-recessive and father-to-son transmission risks. Then walk the management ladder with the cause driving the choice. Miss the male partner and you have cost the couple time and options.^[2][8]

Overview and definition

Male-factor infertility is a contributing cause in roughly 50% of infertile couples — the sole cause in around 30%, a contributing factor alongside female pathology in another 20%. The World Health Organization now defines infertility as a disease of the male or female reproductive system, and NICE NG257 (2026) frames its assessment as a parallel couple workup that begins with BOTH partners at the same visit.^[2][4]

The clinical act that earns the mark is the parallel partner assessment. A couple under 35 with no red flags gets lifestyle advice and a year of expectant management while you confirm a normal semen analysis; a man with azoospermia, severe oligozoospermia, an absent vas, or any clinical male pathology is investigated now — and the female partner is investigated in parallel because male and female factors frequently coexist.^[4][8]

^{[1] [2] [6] [7]}

References12ShowHide

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