Additionally, a reduction in
metabolizable substrates or an increase in metabolic waste
products in the stored semen might also contribute to a
decline in sperm quality. It has recently been shown that
sperm quality (motion characteristics and DNA quality) can
be prolonged (4 days) by centrifuging stored semen and
replacing the supernatant with fresh extender daily [7].
However, whether the resulting improvement in sperm
quality using this technique would improve fertility is unknown.