Alcohol- Having a glass of beer or wine occasionally probably won't affect your chances of getting pregnant, but having two or more drinks a day should be avoided.
Trans fats- This is found in many processed and fast foods, they may be related to ovulation problems and to lower sperm counts and semen quality in men.
Caffeine- Although, there is no substantial evidence that suggest how caffeine impacts fertility. Low to moderate caffeine consumption (less than 200 milligrams a day) shouldn't affect your chances of getting pregnant. But some experts suggest reducing the intake or completely avoiding it especially if you are having difficulty conceiving or if you are undergoing in vitro fertilization.