It has been the custom to require that complete azoospermia be demonstrated in at least 2 specimens to conclude that sterility has been achieved.
The review by ASERNIP-S (Australian Safety and Efficacy Register of New Interventional Procedures – Surgical) published in December 2003 concluded that azoospermia demonstrated in 1 test is sufficient, provided that the test is performed at least 3 months after vasectomy and after at least 20 ejaculations.
ASERNIP-S publication is available at:
Clear written instructions should be provided regarding sample collection and transportation.
Samples should not be collected until after a minimum of 24 ejaculations post-vasectomy with a post-operative interval of 16 weeks.
Collection should occur following an ejaculatory abstinence of no less than 48 hours and no more than 7 days.
The sample should be collected in a wide mouth container and the complete ejaculate must be collected.
The sample should be transported to the laboratory in less than one hour following ejaculation and should be maintained between 20°C and 32°C (see Semen analysis - fertility).