Fertility Blood Markers

Total volume of ejaculate. Low volume may indicate obstruction, retrograde ejaculation, or hormonal insufficiency.

PED: AAS use suppresses gonadotropins (LH/FSH) which can reduce seminal fluid production from accessory glands. Volume may decrease on cycle but is typically the least affected semen parameter. HCG use on cycle helps maintain testicular contribution to volume. Recovery is usually relatively quick post-PCT compared to concentration and motility.

Number of spermatozoa per milliliter of ejaculate. WHO 6th edition lower reference limit is 16,000,000/mL (16 million/mL).

PED: CRITICAL: AAS cause profound suppression of spermatogenesis via HPT axis shutdown. FSH suppression removes the primary signal for Sertoli cells to support sperm development. Most AAS users become severely oligospermic (<5 million/mL) or azoospermic (zero sperm) within 2-3 months of cycle start. HCG maintains intratesticular testosterone but does not fully preserve spermatogenesis without FSH. Recovery post-PCT is highly variable: 6-12 months typical, but some users experience prolonged or incomplete recovery. Values near zero on cycle are expected and not alarming if temporary.

Percentage of sperm showing any movement (progressive + non-progressive). WHO 6th edition lower reference limit is 42%.

PED: Motility is severely impaired by AAS-induced hormonal disruption. Even residual sperm during AAS use often show poor motility due to disrupted epididymal maturation from low intratesticular testosterone. During recovery post-PCT, motility typically lags behind concentration recovery — sperm may return before quality does. HCG on cycle provides some protection. Values near zero on cycle are expected.

Percentage of sperm moving actively forward. WHO 6th edition lower reference limit is 30%. Most clinically relevant motility parameter for natural conception.

PED: Progressive motility is the most functionally important parameter for fertility — sperm must swim forward to reach the egg. AAS suppress this severely. During recovery, progressive motility is often the slowest parameter to normalise. A semen analysis showing adequate concentration but poor progressive motility still indicates impaired fertility. Monitor this marker closely during PCT and recovery if fertility is a goal.

Acidity of the ejaculate. Reflects the balance between the alkaline seminal vesicle fluid and the acidic prostatic secretion.

PED: Rarely abnormal and rarely acted on in isolation, but it becomes genuinely useful in one specific situation: a low volume, acidic, sperm-free sample points toward obstruction or absence of the vas deferens or seminal vesicles rather than a production problem. That distinction matters because it separates a plumbing issue from a spermatogenesis issue, and the two have completely different management. Alkaline pH above about 8 is more often infection or inflammation. On its own an odd pH means little; read it with volume and count.

Motile sperm sticking to each other, head to head or tail to tail. Distinct from aggregation, where sperm clump to debris or immotile cells.

PED: The reason this is on the report is that agglutination is the classic screening clue for anti-sperm antibodies, an immune cause of infertility that a count and motility check will not reveal. Antibodies can follow testicular trauma, infection, torsion, biopsy or vasectomy including reversal, all of which are more common in this population than average. It is graded rather than measured, so a result of 0 is what you want and anything persistent warrants an anti-sperm antibody test rather than a supplement.

Sperm clumping to mucus, debris or non-motile cells, rather than to each other. Less specific than agglutination.

PED: Usually non-specific and much less concerning than agglutination, but persistent aggregation alongside raised white cells can point to genital tract inflammation or infection, which is itself a driver of DNA fragmentation. Read it with the rest of the sample rather than on its own.

The percentage of sperm showing no movement at all. Grade d in the WHO a/b/c/d motility classification, and the arithmetic complement of total motility.

PED: Carries no information beyond total motility when everything is working, since the grades sum to 100%. It becomes interesting when it is very high, because a near-total absence of movement raises questions a motility percentage alone does not: are the sperm dead, or alive but unable to move? That distinction matters. Alive-but-immotile points toward structural problems such as primary ciliary dyskinesia, whereas dead sperm point toward toxic, thermal or oxidative insult. Labs typically run a vitality test when total motility falls below about 20% for exactly this reason.

How fast sperm actually travel, measured by computer-assisted semen analysis. Reported by labs running CASA systems such as the Hamilton-Thorne IVOS.

PED: Only appears on reports from labs using computer-assisted analysis, so it is absent from most manual semen analyses. It adds a little to progressive motility by describing speed rather than just direction: sperm can be graded progressive while moving too slowly to be useful. Interpret it against the reference the analysing lab printed, because CASA parameters are not standardised across machines and a number from one system does not transfer to another.

The share of sperm with head defects. Reported as a breakdown of the abnormal forms, not as a share of all sperm.

PED: Deliberately carries no reference range, because it is descriptive rather than pass or fail. Under strict Kruger criteria only about 4% of sperm are normal even in fertile men, so a figure like 96% here is arithmetic, not alarm: almost every abnormal sperm has some head irregularity. Judge morphology from [Sperm Morphology](/markers/fertility/sperm-morphology) and the [Teratozoospermia Index](/markers/fertility/teratozoospermia-index) instead. Head defects are the sub-type most linked to fertilisation failure, since the head carries the DNA and the acrosome, so a high head-defect share alongside high DNA fragmentation is a more meaningful pairing than either alone.

The share of abnormal sperm with mid-piece defects. The mid-piece houses the mitochondria that power movement.

PED: No reference range, for the same reason as the other morphology sub-types: it is a breakdown of the abnormal forms, not a pass or fail. Its interest is mechanistic. The mid-piece contains the mitochondria, so mid-piece defects tend to travel with poor motility and poor velocity, and both respond to the same mitochondrial support. Excess residual cytoplasm is usually reported nearby and is the more informative of the two.

The share of abnormal sperm with tail defects: coiled, bent, short or doubled flagella.

PED: No reference range, as with the other morphology sub-types. Generally the least clinically weighty of the three, though coiled tails specifically are worth noting because they are associated with osmotic stress and with prolonged abstinence, both of which are easy to change. A high coiled-tail share is one of the few morphology findings with a straightforward practical fix.

Sperm retaining surplus cytoplasm around the mid-piece, a sign they were released before finishing maturation.

PED: The most informative of the morphology sub-types and the one most worth understanding. Retained cytoplasm is not merely cosmetic: it is loaded with enzymes that generate reactive oxygen species, so these sperm actively produce oxidative stress inside the sample rather than just tolerating it. That makes excess residual cytoplasm a mechanistic link to DNA fragmentation, and a plausible explanation when fragmentation is high while count and motility look acceptable. It reflects spermatogenesis being rushed or disrupted, which is exactly what suppression, heat and varicocele do.

The percentage of sperm carrying fragmented DNA. A standard semen analysis counts sperm and looks at how they swim and how they are shaped; this looks at whether the genetic payload is intact, which those measures cannot detect.

PED: This is the parameter most often missed in enhanced athletes, because a semen analysis can come back entirely normal while fragmentation is high. Count, motility and morphology describe the delivery; fragmentation describes the cargo. The main driver is oxidative stress in the epididymis, which is why it responds to things a normal semen analysis does not: heat, smoking, varicocele, infection, obesity, age, and long abstinence. AAS use matters indirectly. Suppressed intratesticular testosterone impairs spermatogenesis, and a stressed spermatogenic environment produces more fragmentation, but the bigger practical issue is that men often check a semen analysis post-cycle, see acceptable numbers, and assume fertility has recovered. Elevated fragmentation is associated with lower natural conception rates, lower IVF fertilisation and higher miscarriage risk even when conventional parameters look fine. Because the spermatogenic cycle is roughly 74 days, nothing you change today shows up for about three months, so retest at 3 months rather than 3 weeks. Methods differ (Halosperm, SCSA, TUNEL, comet) and their thresholds are not interchangeable, so compare against the range your own lab printed rather than a number from a forum.

Sperm concentration multiplied by semen volume, giving the total number of sperm in the whole ejaculate. WHO lower reference limit is 39 million.

PED: Often a better measure than concentration alone, because concentration is diluted or concentrated by whatever volume the accessory glands happened to produce that day. A man with a low concentration but a large volume can have a perfectly normal total count. On suppressive compounds this falls along with concentration and is one of the clearest numbers to track through recovery, since it captures both the volume and concentration effects in a single figure.

Volume multiplied by concentration multiplied by motility: the number of actually moving sperm in the whole ejaculate. Widely used to decide between natural conception, IUI and IVF.

PED: The single most practically useful number on a semen analysis, because it combines the three parameters that matter into one figure and maps directly onto treatment decisions. Rough clinical bands: above 20 million is generally reassuring for natural conception, 5 to 20 million is where IUI is typically considered, and below about 5 million tends to push toward IVF or ICSI. It falls hard on suppressive compounds and recovers as concentration and motility recover. If you track one fertility number through a recovery protocol, this is the one, since it will not flatter you the way an isolated normal-looking concentration can.

The average number of defects per abnormal sperm. A single sperm can have a head defect, a mid-piece defect and a tail defect at once, and this captures how many faults the abnormal ones carry on average.

PED: Reported alongside morphology by labs using strict WHO criteria, and usually flagged above about 1.80. It adds information morphology alone does not: two men can both have 4% normal forms, but one whose abnormal sperm carry a single minor defect each is in a different position from one whose abnormal sperm are multiply defective. A rising index alongside falling morphology suggests spermatogenesis is under more strain rather than simply producing fewer good cells, which is the pattern seen with suppression, heat and oxidative stress.

Percentage of sperm with normal shape and structure (strict Kruger criteria). WHO lower reference limit is 4%.

PED: Morphology reflects the quality of spermatogenesis. AAS-disrupted hormonal milieu produces abnormal sperm forms (teratozoospermia). Even naturally, only a small percentage of sperm are morphologically normal — the 4% threshold is already low. During AAS use, morphology typically drops below this threshold. Recovery of normal morphology post-PCT can take 3+ months after concentration recovers, as it reflects a full spermatogenic cycle (~74 days). Persistently abnormal morphology after prolonged recovery may warrant fertility specialist referral.

A hormone secreted by the Sertoli cells of the testes that reflects the integrity of the seminiferous tubules and the level of spermatogenesis. It provides negative feedback on pituitary FSH secretion and correlates with sperm production and testicular volume.

PED: One of the most useful markers of testicular reserve in AAS users. Exogenous androgens shut down LH and FSH, which starves the testes of the signals that drive spermatogenesis; inhibin B falls as Sertoli-cell output declines. A low inhibin B in a suppressed athlete signals impaired spermatogenesis and, alongside FSH and sperm analysis, helps predict how readily fertility will recover during a PCT or a restart protocol. A very low or undetectable inhibin B after long or heavy cycles is a warning sign that recovery may be slow or incomplete.

A hormone produced by the granulosa cells of ovarian follicles in women and by the Sertoli cells of the testes in men. In women it is the standard marker of ovarian reserve (the remaining egg supply), and in men it reflects Sertoli-cell mass and testicular function. Levels are relatively stable across the menstrual cycle, which makes AMH a convenient single-draw test.

PED: In men, AMH is a marker of Sertoli-cell function and sits alongside inhibin B and FSH in a fertility workup. Unlike the female picture, adult male AMH is inversely related to intratesticular testosterone: it is high before puberty and is suppressed by the high intratesticular testosterone that normal (or AAS-driven) androgen exposure produces. Because AAS shut down the gonadotropin signals that maintain Sertoli-cell activity and spermatogenesis, a fertility panel in a suppressed athlete is better anchored on inhibin B, FSH, and a semen analysis; AMH is supportive rather than the primary readout in men. For any female users, AMH is the single most useful test of ovarian reserve, important context for those planning fertility while using compounds that disrupt the cycle. Interpret female AMH strictly against age-specific ranges.