Can caffine negatively effect the male sperm count?

Inconclusive evidenc: The data on this are inconclusive. In 1 study, high caffeine use (>14 0.5-l bottles/week) and/or caffeine (>800 mg/day) was associated with reduced sperm concentration and total sperm count. But these results were only significant for cola. http://www.ncbi.nlm.nih.gov/pubmed/20338976 the men in these studies could have had other unhealthy lifestyle practices too.

Yes: Caffeine can decrease sperm count. When couples are trying to get pregnant it can be helpful for both partners cut back. Caffeine itself does not decrease it enough to use as a birth control method.