This tab covers the cornerstone of the male work-up — the semen analysis — along with secondary semen tests, serum hormones, and post-ejaculate urinalysis.
Semen Analysis
The sample should be examined within 1 hour of collection after 2–3 days of abstinence, with at least two analyses a month apart (and a repeat 1–2 weeks later if azoospermic). The WHO lower limits are the 5th percentile derived from men whose partners conceived within a year — values below them do not by themselves diagnose infertility, but the odds of infertility rise with the number of abnormal parameters. The parameters individually diagnostic of infertility are azoospermia, necrozoospermia, complete asthenozoospermia, and complete globozoospermia.
| Parameter | Lower reference limit |
|---|---|
| Semen volume | 1.5 mL |
| Total sperm number (most important) | 39 million/ejaculate |
| Sperm concentration | 15 million/mL (oligospermia below) |
| Total motility | 40% |
| Progressive motility | 32% |
| Normal morphology | 4% (teratozoospermia below) |
| Vitality | 58% |
- Low volume (<1.5 mL) — from obstruction/hypoplasia (CBAVD, severe androgen deficiency), α-blockers, retrograde ejaculation (sperm pass backward into the bladder — vs aspermia, a dry ejaculate), or incomplete collection. Hypervolemia (>5 mL) dilutes sperm.
- Asthenospermia (total motility <40% or progressive <32%) — from structural defects, prolonged abstinence, infection, anti-sperm antibodies, partial obstruction, or varicocele.
- Teratozoospermia (<4%) — globozoospermia (no acrosome → small round heads) requires ICSI (ejaculated sperm are available, so no surgical extraction); strict morphology should not be used in isolation for decisions.
- Vitality (<58%) — necrospermia; if motility is 0%, a vital stain distinguishes necrospermia, and electron microscopy can confirm immotile cilia syndrome (managed with IVF).
- Azoospermia — confirm by centrifuging and examining the pellet for rare sperm, then repeat. Normal-volume azoospermia reflects obstruction or a spermatogenic problem; low-volume azoospermia with acidic pH suggests genital-tract obstruction, while normal pH (>7.2) suggests incomplete collection, retrograde ejaculation, or partial obstruction (normal semen pH is 7.2–7.8).
Secondary Semen Analyses
- Sperm DNA fragmentation (TUNEL, Comet assays) — associated with lower pregnancy and higher miscarriage rates; not used in the initial work-up but useful with repeated IVF failure. There is no corrective therapy, but options include testicular (vs ejaculated) sperm with ICSI (higher live-birth rates), antioxidants, varicocele repair, and reduced abstinence.
- Semen leukocytes — round cells >1 million/mL are abnormal; staining (Papanicolaou/immunocytochemistry) distinguishes pyospermia (WBCs — evaluate for infection/STI) from harmless immature germ cells.
- Anti-sperm antibodies — follow disruption of the blood-testis barrier (trauma, mumps orchitis, vasectomy → ASA in 60–80%); IgA and IgG predominate. Test only if it will change management (not before ICSI); ICSI gives higher pregnancy rates than IUI in affected couples.
- Sperm aneuploidy testing (FISH for chromosomes 13, 18, 21, X, Y) — indicated for recurrent pregnancy loss.
- Fructose (from the seminal vesicles) — low semen fructose suggests ejaculatory-duct obstruction.
Serum Hormones
FSH and morning total testosterone are not first-line; obtain them for azoospermia, oligozoospermia (<10 million/mL), impaired libido, ED, atrophic testes, or a hormonal abnormality on exam. FSH indirectly reflects germ-cell mass: a testis <4.6 cm with FSH >7.6 IU/L suggests spermatogenic failure, whereas a larger testis with FSH <7.6 suggests obstruction. If morning testosterone is <300 ng/dL, add free/bioavailable testosterone, LH (distinguishes primary from secondary hypogonadism), estradiol (a total T:E ratio <10:1 indicates reproductive dysfunction), and prolactin (a labile assay — confirm before acting; MRI if very high).
| Hormone | Severe spermatogenic failure | Obstructive azoospermia | Hypogonadotropic hypogonadism |
|---|---|---|---|
| LH | ↑ or normal | Normal | ↓ |
| FSH | ↑ | Normal | ↓ |
| Testosterone | ↓ or normal | Normal | ↓ |
Post-ejaculate Urine
A post-ejaculate urinalysis diagnoses retrograde ejaculation; viable sperm recovered from the urine can be used with ART.
Self-Test
1. List the WHO semen parameters and their lower reference limits. Volume 1.5 mL; total sperm number 39 million/ejaculate; concentration 15 million/mL; total motility 40%; progressive motility 32%; normal morphology 4%; vitality 58%.
2. List six causes of low semen volume. Obstruction/hypoplasia (CBAVD), severe androgen deficiency, ejaculatory-duct obstruction, retrograde ejaculation, α-blockers, and incomplete collection (or short abstinence).