OHSU

OHSU Center for Women's Health

Where Healing, Teaching and Discovery Come Together


Optimized Sperm Penetration Assay (SPA)

Specialized Method of Semen Analysis

The routine semen analysis is a relatively insensitive method of assessing male fertility since a significant number of fertile and infertile men have similar semen parameters. The Optimized SPA is a second generation test for the evaluation of sperm function. The optimized SPA method enables the doctor to more accurately select those patients who will benefit most from IUI, IVF, or ICSI regardless of semen quality.

The population suitable for SPA testing includes

  • Infertile couples experiencing unexplained infertility
  • Patients with a normal semen analysis that have failed >3 IUI attempts
  • Male factor patients considering IVF

The SPA specifically measures sperm capacitation. That is the capacity of sperm to undergo the complex membrane changes necessary to fertilize a human egg. For this test, specially prepared hamster eggs are used to detect such sperm function. Only after sperm capacitate are they able to bind to and penetrate these hamster eggs. Therefore, by measuring the degree to which sperm penetrate hamster eggs, one can determine functional potential for these sperm with human eggs.

For the SPA we can obtain specimens from the patient locally or offsite via Mail-in (e.g. FEDEX).We find no differences in the analysis between locally obtained specimens and those that are shipped.

Sperm Penetration Assay

This zona-free hamster egg contains more than 20 penetrated sperm. The sperm heads swell as the tightly packed DNA begins to disperse to start forming chromosomes.

Schedule an Appointment

503 418-4500
or
855-230-4500 (toll-free)