Penetration of zona-free hamster ova and bovine cervical mucus by fresh and frozen human spermatozoa.

Semen samples from 25 fertile donors and 34 infertility patients were analyzed and evaluated both fresh and frozen with the zona-free hamster egg penetration test (EPT) and the bovine cervical mucus penetration test (MPT). Cryopreserved sperm penetrated 47.2% (average) of the hamster eggs, and fresh sperm penetrated 55.9%. Frozen sperm retained 86% of the fresh EPT values (P, not significant), but only 38% of the fresh MPT values (P less than 0.001). Cryopreserved sperm yielded the same fertility classification as fresh sperm in 94% of the cases with the EPT but only 43% with the MPT. The use of cryopreserved sperm simplifies the procedure and should enable more laboratories to utilize the EPT, but the poor results with the MPT preclude utilization of cryopreserved sperm for routine fertility evaluation with the MPT.