Perhaps you should try some spelling variations:
decreases sperm » decreased sperm (Expand search), decreases serum (Expand search), decreasing sperm (Expand search)
sperm decrease » term decrease (Expand search), speed decrease (Expand search), speed decreases (Expand search)
decrease any » decrease and (Expand search), decreases and (Expand search), decreased and (Expand search)
any decrease » and decrease (Expand search), can decrease (Expand search), may decrease (Expand search)
decrease of » decrease in (Expand search)
of decrease » or decrease (Expand search), not decrease (Expand search), to decrease (Expand search)

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

• Removing quotes may allow a broader search: (( decrease any decrease of decrease ) OR ( decreases sperm decrease AND object ))~.