Perhaps you should try some spelling variations:
decreases sperm » decreased sperm (Expand search), decreases serum (Expand search), decreasing sperm (Expand search)
after decreases » after deceased (Expand search), water decreases (Expand search), after decades (Expand search)
decrease after » disease after (Expand search)
sperm meters » speed meters (Expand search), sperm parameters (Expand search), sperm after (Expand search)
decrease or » decrease of (Expand search), decrease pro (Expand search), decrease toc (Expand search)
or decrease » of decrease (Expand search), not decrease (Expand search), to decrease (Expand search)
decrease on » decrease in (Expand search), decrease of (Expand search), decrease and (Expand search)
on decrease » on decreased (Expand search), of decrease (Expand search), and decrease (Expand search)

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( decrease OR decrease on decrease ) OR ( decrease after decreases sperm meters ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease or decrease on decrease ) OR ( decrease after decreases sperm meters ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease or decrease on decrease ) OR ( decrease after decreases sperm meters ))*.