Recent publications have shown that less time between semen production and analysis significantly influence pregnancies and live birth (1).

One of the reasons is probably the fact that ejaculates show rapid increase in osmolality, which affects motility when exposed a medium with lower osmolality (2).

Interesting reading, recommended!


  1. Time intervals between semen production, initiation of analysis, and IUI significantly influence clinical pregnancies and live births U.Punjabi et al, Center for reproductive medicine ,Belgium  Journal of Assisted Reproduction and genetics nov.2020
  2. Hypotonic challenge reduces human sperm motility through coiling and folding of the tail. Holmes E et al Andrologia 2020