The diagnosis of oligospermia is determined through a semen analysis (spermiogram) test. To ensure accurate results, the semen sample must be collected following a strict 3-day period of sexual abstinence. Samples obtained after periods significantly shorter (e.g., 1 day) or longer (e.g., 10 days) than this recommended window will not yield reliable diagnostic information. It is crucial that the male observes this 3-day abstinence before providing the sample for analysis.