A healthy 27-year-old male and his partner have been attempting to conceive for more than 1 year. As part of their evaluation he has a semen analysis. His ejaculate volume is 3.5 mL, sperm concentration is 8 million/mL, sperm motility is 65%, oval forms comprise 60% of the sperm, and fructose is present in the ejaculate.
The man is treated with clomiphene for a presumptive diagnosis of male factor infertility. Though clomiphene is an unproven and unapproved therapy for male infertility, what is the earliest that a semen analysis should be done to detect an improvement in his semen parameters?
- 33 days
- 53 days
- 73 days
- 90 days
- 120 days
Answer(s): D
Explanation:
The cycle of spermatogenesis is 73 ± 5 days.
This is the time required for maturation of spermatogonia to spermatozoa. The cycle is at different stages along the seminiferous tubules, necessary to ensure the presence of sperm in each ejaculate. Further, spermatozoa require approximately 3 weeks to traverse the ductal system and appear in the ejaculate.
Knowing this has important implications: any therapy intended to stimulate spermatogenesis must be continued for at least the duration of one spermatogenic cycle to determine whether there is a beneficial effect. While impaired spermatogenesis may occur late in the cycle of spermatogenesis and improvement with clomiphene may occur sooner, the semen analysis should still be delayed for 90 days to provide better evidence for the presence or absence of improvement in the semen analysis.
Results must be interpreted with caution because there
is great biological variability in semen parameters: what is interpreted as a therapeutic effect may only be natural biological variation. Ultimately, pregnancy is the only meaningful measure of treatment success and pregnancy may have occurred despite the therapy, not because of it.