Is fresh or frozen semen to be used in in vitro fertilization with donor sperm?

Sixty-six partners of either severely oligoasthenospermic or azoospermic men were treated by in vitro fertilization with donor sperm (IVF-D), usually (86%) after failure of artificial insemination with donor sperm. One hundred twenty-nine IVF trials were performed with either fresh (59%) or frozen-thawed (41%) donor sperm. Characteristics of sperm preparations were significantly lower in the frozen-thawed group (P less than 0.001). In the latter group, fertilization rates had slightly decreased (but without statistical significance); embryonic vitality scores and cryopreservable spare embryos had significantly decreased (P less than 0.05). However, cumulative ongoing pregnancy rates were strictly equivalent in both groups (40% after three trials). Frozen-thawed sperm thus can be substituted for fresh donor sperm without entailing impairment of the outcome of IVF, and this method must be preferred for its greater safety regarding transmission of human immunodeficiency virus.