Optimization of IVF pregnancy outcomes with donor spermatozoa.

PURPOSE: To identify risk factors for suboptimal IVF outcomes using insemination with donor spermatozoa and to define a lower threshold that may signal a conversion to fertilization by ICSI rather than insemination.

METHOD: Retrospective, age-matched, case-control study of women undergoing non-donor oocyte IVF cycles using either freshly ejaculated (N=138) or cryopreserved donor spermatozoa (N=69). Associations between method of fertilization, semen sample parameters, and pregnancy rates were analyzed.

RESULTS

In vitro fertilization of oocytes with donor spermatozoa by insemination results in equivalent fertilization and pregnancy rates compared to those of freshly ejaculated spermatozoa from men with normal semen analyses when the post-processing motility is greater than or equal to 88%. IVF by insemination with donor spermatozoa when the post-processing motility is less than 88% is associated with a 5-fold reduction in pregnancy rates when compared to those of donor spermatozoa above this motility threshold. When the post-processing donor spermatozoa motility is low, fertilization by ICSI is associated with significantly higher pregnancy rates compared to those of insemination.

CONCLUSION

While ICSI does not need to be categorically instituted when using donor spermatozoa in IVF, patients should be counseled that conversion from insemination to ICSI may be recommended based on low post-processing motility.