10 Things to know about Sperm and Male Fertility
It takes two to make a baby, often in clinic I see women making huge effort and lifestyle changes but not much is changing for men, so here are 10 easy things men can do to help male fertility.
No 1. In the 6th edition of the WHO manual on semen analysis (2021), sperm parameters have been updated from standard values to ranges. Take normal forms as an example. I believe this change reflects what is actually required for good fertility. Previously, 4% was classed as ‘normal’ because, globally, this is the average percentage of normal forms in semen. FYI, I have never seen anyone in the “normal” group 1 in my clinic.
· Normal: greater than or equal to 14%
· Borderline: between 4-13%
· Pathological: less than 4%
No 2. Male infertility is not just about sperm; it’s also linked to overall health. Risk factors for the following conditions increase with male infertility:
· Testicular cancer
· Melanoma
· Prostate cancer
· Thyroid cancer
· Non-Hodgkin lymphoma
· Acute lymphoblastic leukaemia
No 3. It takes at least 90 days to improve sperm quality, with 10 weeks being the absolute minimum. Sperm cells spend 64 days in the testes, then are transported to the epididymis (next to the testes) for final maturation over the remaining days.
No 4. Approximately 300 million sperm cells enter the vagina during intercourse, but only about 300 make it to the egg. At conception, a “team” of about 100-150 sperm work together to penetrate the zona pellucida (the egg’s outer layer), but only one fertilizes the egg.
No 5. Sperm can survive for up to 7 days in the female genital tract (with 4-5 days being the average), but the ideal fertilization day is the first day of entering the female body.
No 6. Interestingly, the egg “chooses” the sperm and can fix certain DNA issues. The first three days of embryo development are driven by maternal mitochondria, while paternal DNA takes over after day 3. So, if embryo development consistently stops after day 4, further investigation into sperm quality is needed. A 5-day blastocyst is only possible if the male DNA is good.
No 7. A single sperm contains about 35 megabytes of data. Therefore, an average ejaculate contains roughly 1500 terabytes of data-the equivalent of downloading 10 billion Facebook photos.
No 8. A thorough semen analysis is essential. Many markers should be checked, including pH, appearance, viscosity, liquefaction, round cells, head shape, leukocytes (indicating infection), as well as the usual parameters like count, motility, morphology, and viability. A DNA fragmentation test is also crucial.
No 9. Like women, men’s fertility declines with age, and paternal age is on the rise. The chance of conceiving within the first year for a man over 35 is 50% lower than for a man under 25. While paternal age is not an absolute barrier to conception, there are increased DNA strand breaks in the sperm of older men. This DNA fragmentation leads to a higher rate of early miscarriages.
No 10. Lastly, women are often criticized for being overweight (or underweight) when it comes to fertility, but this is often overlooked in men. It is equally important for men. A 2006 study found that male fertility decreases by 10% for every 10% increase in body weight. Overweight men have a higher rate of azoospermia (no sperm) or oligospermia (low sperm count). They are also more likely to have poor sperm morphology, vitality, motility, and DNA integrity.