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There is a Buddhist parable of blind men describing an elephant. The man facing the elephant says it’s thick like a snake. The man who grabs its large floppy ear thinks it’s fan-shaped. The man who grabs its leg insists that it’s a tree trunk and the one on its side believes it to be a wall. All of them right, sort of. But the big picture’s missing, isn’t it?
Given that the semen analysis has been the cornerstone of the male fertility evaluation for at least 50 years, it’s remarkable for how long we’ve gotten by with so little information.
We love to count things. Maybe, by so ordering our universe, we get a sense of belonging or control over the environment. And of course, for the last 100 years or so, we have counted the sperm in our semen. But unlike a blood glucose level, which is incredibly tightly regulated, sperm are part of a more loosey-goosey biological secretion that varies by year, season and even by day. This makes “normal” values or “reference” ranges for semen quality complicated and somewhat artificial. Bottom line: unless it reads zero, the semen analysis is a poor measure of a man’s true fertility potential.
Despite these caveats, the semen analysis has some value. When viewed over time, it may reveal health-related patterns. Like the slowly declining sperm counts associated with the progressive effects of a varicocele, increased obesity or uncontrolled diabetes. More profound is the recently described relationship of semen quality as a “biomarker” of disease, mortality, and higher rates of later cancers in men. Yes, although this onion is not fully peeled, semen quality appears to a window into men’s current and future health.
A Man’s Story
When taken in full clinical context, along with the clinical history and physical examination, the semen analysis can often tell a story. Think of sperm production as an engine that wants to run hard, at full tilt. When all is well and the body is at peak performance, the semen analysis tends to be normal. However, with ill health or a bad diet, sperm production is hampered and sperm counts fall.But the bean-counted semen analysis is only part of the story. Men with normal semen analyses can be frankly infertile and men with abnormal semen quality can be fully fertile. In fact, there is virtually no linearity to the relationship between semen quality and fertility. What gives? Much of the secret to fertility, we're learning, has nothing to do with sperm numbers or movement but is to be found in the health of the sperm DNA payload. The way that sperm DNA is packaged (fragmentation) and marked (epigenetics) matters immensely not only to conception but also to fetal development. And as our understanding of what determines the build quality of the DNA payload improves, it is our belief that the single most important factor will end up being the health of the man who makes it. And, lucky for us this is something we can do something about.