First recorded pregnancy and normal birth after ICSI using electrophoretically isolated spermatozoa

BACKGROUND: DNA damage in the male germ line is associated with poor fertilization and cleavage rates, impaired embryo quality and early pregnancy loss. Given these associations, embryologists are keen to develop techniques that will allow the selection of viable spermatozoa exhibiting low levels of DNA damage for assisted conception purposes. METHODS: In this article, we describe a novel electrophoretic approach for the rapid isolation of cells possessing little DNA damage. The limits of the method were examined using cryostored and snap-frozen semen samples as well as testicular biopsy material. In addition, clinical utility was demonstrated in a case study involving treatment of a patient exhibiting persistently high levels of DNA damage in his spermatozoa. RESULTS: From a range of difficult starting materials (biopsies, cryostored semen and snap-frozen sperm suspensions), the electrophoretic system rapidly isolated populations of motile, viable, morphologically normal spermatozoa exhibiting high levels of DNA integrity. Clinical application in a couple suffering from long-term infertility associated with extensive DNA damage in the male germ line led to the first human pregnancy following such electrophoretic sperm isolation. CONCLUSIONS: The electrophoretic procedure holds promise as a convenient method for the rapid preparation of high-quality spermatozoa for assisted conception purposes.