Alcohol
Alcohol restriction is generally recommended to the woman when one is seeking fertility treatment. It is possible that even a minor daily alcohol intake (1 to 5 drinks weekly) may reduce fecundity. When pregnant – no alcohol consumption is recommended.
Alcohol consumption does not seem to influence sperm quality if the intake is reasonable. High daily alcohol consumption is related to increased estrogen levels in males and is associated with impaired fertility.
Tobacco
It is proven that fecundity is severely impaired among women who smoke. Among males the sperm quality is reduced by smoking. You should stop smoking before initiating fertility treatment, whether you are a man or a woman.