Semen Analysis: What Do the Results Mean?

A semen analysis (spermogram) is the primary diagnostic test used to evaluate male fertility. It assesses both the quantitative and qualitative characteristics of seminal fluid and sperm cells.

While a semen analysis provides important diagnostic information, a single abnormal result does not automatically mean a man is infertile. Semen parameters naturally fluctuate due to recent illness, stress, abstinence length, lifestyle factors, and lab variability. Understanding what each parameter measures — and how the results are interpreted together — is essential.

Semen volume (total fluid per ejaculate) — ≥1.4 mL. Sperm concentration (cells per mL) — ≥16 million/mL. Total sperm count per ejaculate — ≥39 million. Total motility — ≥42%. Progressive motility (forward movement) — ≥30%. Morphology (share of normally shaped cells under strict criteria) — ≥4%. pH — ≥7.2. Total motile count (volume × concentration × % progressive motility) — ≥15–20 million.

Semen volume reflects the combined secretions of the seminal vesicles (~65–70%), prostate (~25–30%), and bulbourethral glands. A low volume (6.0 mL) may dilute sperm concentration or indicate active inflammation in the accessory glands.

Concentration is the density of sperm in one milliliter of fluid, while total sperm count multiplies concentration by the entire ejaculate volume. This distinction matters: a man with a lower concentration but a higher volume may still have a healthy total sperm count.

For natural conception, sperm must swim progressively through the female reproductive tract: progressive motility means moving actively forward or in large circles; non-progressive motility means moving the tail without forward progress; immotile sperm show no movement.

Morphology assesses the shape and physical structure of sperm under a high-power microscope. A normal cell has an oval head, an intact acrosome cap, a well-defined midpiece, and a single straight tail. Under strict WHO criteria, having as few as 4% normally shaped sperm is still considered normal for natural fertility.

When parameters fall below reference values, doctors use specific terms: normozoospermia — all parameters within normal limits; oligozoospermia — low sperm concentration or count; asthenozoospermia — reduced motility; teratozoospermia — reduced normal morphology; OAT syndrome — a combination of low count, motility, and shape; azoospermia — complete absence of sperm in the ejaculate; aspermia — a total absence of ejaculated fluid.

Varicocele — enlarged scrotal veins that raise testicular temperature and adversely affect count, motility, and morphology. Hormonal imbalances — low LH/FSH or elevated prolactin. Infections — prostatitis, epididymitis, or sexually transmitted infections causing temporary damage or obstruction. Lifestyle and environmental exposure — heat (saunas, hot tubs), smoking, excessive alcohol, heavy cannabis use, obesity, and severe psychological stress. Medications — anabolic steroids, testosterone therapy, and certain prescription drugs.

Because sperm development (spermatogenesis) takes approximately 72 to 90 days, semen parameters vary naturally over time, and a single test result should never be treated as a final diagnosis.

Routine follow-up is typically recommended 2 to 4 weeks after the initial analysis to establish a true baseline. After a recent illness or fever — a high fever or viral infection can temporarily impair sperm production for up to 3 months, so repeat testing should be delayed until 8 to 12 weeks after recovery. Following lifestyle changes or treatment — when evaluating medical therapy, varicocele repair, or lifestyle changes, repeat testing is generally scheduled 3 months later to allow a full new cycle of sperm development.

Preparation requirements for repeat testing: a strict abstinence window of 2 to 7 days, collecting the entire sample directly into a sterile container, protecting the sample from temperature extremes, and delivering it to the laboratory within 30 to 60 minutes if collected off-site.

Can a man with a low sperm count get his partner pregnant? Yes. Lower parameters reduce the overall statistical probability per cycle, but pregnancy is still possible as long as viable, progressively motile sperm are present.

Does abnormal morphology mean a child will have birth defects? No. Morphology describes the physical shape of the sperm cell and its ability to penetrate an egg — it does not correlate with genetic abnormalities or congenital defects in offspring.

What is the difference between azoospermia and aspermia? Azoospermia means semen is ejaculated but contains zero sperm cells. Aspermia means there is a total absence of ejaculated fluid altogether.