There is no evidence to prove that fertility is affected by moderate alcohol consumption. However, since alcohol should be avoided completely during pregnancy, and you wouldn't know exactly when conception has happened, it is advisable to avoid alcohol altogether if you can help it for the sake of your fetus. http://www.webmd.com/baby/guide/8-ways-to-boost-your-fertility?page=2
To me, anything that is toxic maybe able to affect the chances. Afterall is toxic to the body. With moderation if you are saying a glass of wine occasionally may be alright. Bur if you are a heavy drinker, ill suggest for you to change your lifestyle.
yes thats why most ob gyne would recommend abstaining from alcohol and caffeine if you’re trying for a baby
thanks