Yes, sterility after a vasectomy does not occur automatically. Although this surgery cuts the vas deferens, it is normal for viable residual sperm to remain in the ducts. Therefore, during the first few months after the vasectomy, those live sperm continue to be released during ejaculation.
However, the expulsion of these sperm does not depend solely on the amount of time that has passed since the procedure, but also on the frequency of ejaculations. Generally, between 20 and 30 ejaculations are required to clear the tubes.
For this reason, patients are advised to use another form of birth control, such as condoms, until post-vasectomy follow-up semen analyses are performed. Only when the laboratory confirms azoospermia—the total absence of sperm in the sample—can the patient be medically cleared, and the vasectomy considered a permanent method of birth control.
